Abstracts from the 2024 AMSA Reciprocal Meat Conference 

1 USING ONLINE ATTITUDINAL AND COMPLETION TESTS TO UNDERSTAND CONSUMER PERCEPTION OF PROBIOTIC DRY-FERMENTED SAUSAGE

M. M. S. Karwowski¹, E. Francisco-Maffezzolli², E. C. Boiko¹, R. E. F. Macedo^1,*, ¹Graduate Program in Animal Science, ²Business School, Pontifical Catholic University of Parana, Curitiba, Brazil *renata.macedo@pucpr.br

Objectives: This study aimed to assess consumer perceptions and the connections between consumers’ health-related concerns and their perceptions of probiotic fermented sausage.

Materials and Methods: The study was carried out using a 4-step online questionnaire composed of (1) identification and recruitment; (2) application of the completion test; (3) attitudinal exploration; and (4) socioeconomic inquiry. The online test was focused on identifying the key factors influencing consumers’ choices when purchasing fermented sausages, both traditional and probiotic. The data were collected using QualtricsXM software® and distributed through social media using snowball sampling. For the completion test, participants were asked to complete 4 dialogues simulating a purchase situation. The participants were also asked to answer a questionnaire on how much they agreed with a list of sentences about their attitude toward health. A total of 201 participants were considered.

Results: Sixteen categories emerged from the terms mentioned by consumers that encouraged or restricted the intention to purchase fermented sausage. Three different consumer groups were formed from the attitudinal profile results (High Health Concerned [HHC], Moderate Health Concerned [MHC], and Low Health Concerned [LHC]). No significant differences were observed among clusters concerning the reasons that encourage the purchase of dry-fermented sausage (χ2 = 6.57, P =0.765) and probiotic sausage (χ2 = 16.06, p = 0.488). Considering the entire consumer group (N = 201), the leading categories that encourage the purchase of traditional sausages were “good flavor” (35%) and “consumption preferences” (23%). Within HHC, “good flavor” was mentioned by 36% of respondents, while MHC mentioned it in 41% of cases and LHC in 23%. Similarly, the leading categories that encourage the purchase of probiotic sausage were “healthy” (45%), and “curiosity” (42%). “Healthy” was more frequently mentioned by consumers in HHC. In contrast, consumers in MHC expressed a greater frequency of “curiosity.” Regarding the reasons that restrict the purchase of dry-fermented sausage, whether traditional or probiotic, marginal differences (P < 0.10) were found among clusters (χ2 = 29.61, P = 0.076 for traditional and χ2 = 27.07, P = 0.078 for probiotic sausage). The main limitations for the purchase of traditional sausage were “unhealthy” (48%), “expensive” (25%), and “disinterest” (14%). “Unhealthy” was the most mentioned category by HHC. On the other hand, “expensive” was mentioned at a higher frequency by MHC. The main category that restricted the intended purchase of functional sausage was “probiotic unawares” (48%), followed by “unpleasant flavor” (44%) and “unhealthy” (29%). Interestingly, consumers of HHC showed a similar lack of knowledge about probiotic meaning as consumers of LHC.

Conclusion: The driving factors that encouraged the intention to purchase probiotic sausage were the product’s association with health benefits and curiosity. The belief that the functional product is not tasty and the unfamiliarity with the probiotic concept restricted the intention to purchase it. A multifaceted marketing approach is needed for the market of probiotic fermented sausage with a focus on the education of consumers about the health benefits and the sensory attributes of the product.

Keywords: consumption, functional food, health, projective techniques

2 IMPACT OF TRAINING ON ANCHORING BIAS IN SURVEY QUESTIONS REGARDING PERCEPTION OF FRESH PORK PRODUCTS

J. Girman^1,*, C. Gill¹, N. Adolph¹, B. Harsh¹, A. C. Dilger¹, ¹Animal Sciences, University of Illinois, Urbana-Champaign, Illinois, United States *jenngirman@gmail.com

Objectives: Price, convenience, freshness, and perception of quality are among the top traits consumers select for when purchasing fresh meat products (Lusk and Briggeman, 2009). Consumers struggle to make analytical decisions during purchasing, and rather utilize their knowledge, the media, and other measurable factors such as labels (Hoque et al 2018). The anchoring effect is a type of consumer bias that proposes consumers are not necessarily rational when they make decisions and instead use the most accessible information that they have at the time to make decisions and answer questions (Shan et al., 2020). The present study aimed to investigate the impact of anchoring bias on consumer responses regarding fresh pork products.

Materials and Methods: Consumers were assigned one of 3 conditions for this experiment before completing a series of survey questions. These conditions included orientation, completion of a pork appearance card-sorting activity, and no orientation or sorting activity. The orientation included what consumers should look for in terms of pork color and marbling, with specific photos and examples of light versus dark color and slight versus heavy marbling. The card-sorting activity placed 5 photos of pork loin chops between 2 anchor points and asked participants to place them in rank order to the best of their ability (for groups assigned no orientation). Groups assigned orientation were asked to place cards from lightest to darkest between the anchor points. An additional 2 sets of cards analyzed consumer ability to perceive marbling and placed 7 cards between 2 anchor points, asking consumers to sort them from least to most amount of marbling. Qualitative responses were analyzed for keywords (light coloring, dark coloring, and marbling) used in the orientation. Responses were coded (Yes = 1, No = 0) for instances of keywords. Frequency of keyword usage in responses were calculated for each experimental group. Additionally, keyword frequency was also calculated for groups based on age, gender, and ethnicity.

Results: If no anchoring effect were present, consumer use of keywords would be expected to be similar between all conditions. Significant differences (P < 0.05) were found in participants that received orientation and participants that completed a card-sorting activity regarding color and marbling of fresh pork-loin chops compared with groups that completed their survey without any orientation or activity. Usage of keywords was greater in groups that received orientation only and groups that completed the card-sorting activity compared with groups that did not receive orientation and completed a card-sorting activity after taking the survey. Keyword usage frequency did not differ between age or gender groups (P > 0.69). However, significance was found in comparing means among different ethnic groups (P < 0.05). Specifically, consumers that identified as African American or Caucasian responded with proportionally higher frequencies of keywords compared to the other ethnic groups.

Conclusion: This study suggests that consumers are influenced by information given prior to completing survey questions, which could impact recorded responses. Consumers may respond with biased opinions that do not directly reflect their actual purchasing behavior. Similar studies could be conducted to determine the influence bias has on consumer attitudes related to the meat industry.

Funding Source: University of Illinois Meat Science Lab

Keywords: anchoring bias, consumer perception, marbling, pork color, pork quality

3 U.S. CONSUMER PERCEPTION OF BEEF COLOR—A MIXED METHODS APPROACH

A. J. Thies^1,2,*, B. A. Altmann³, A. M. Countryman⁴, C. L. Smith², M. Holloway², M. N. Nair², ¹Institute of Market Analysis, Johann Heinrich von Thuenen Institute, Braunschweig, Germany, ²Department of Animal Sciences, Colorado State University, Fort Collins, Colorado, United States, ³Faculty of Organic Agricultural Sciences, University Kassel, Kassel, Germany, ⁴Department of Agricultural and Resource Economics, Colorado State University, Fort Collins, Colorado, United States *colton.smith@colostate.edu

Objectives: Discoloration of beef products leads retailers to discount or discard beef products due to consumer rejection. This practice contributes to food waste, which leads to the wastage of economic and natural resources associated with meat production. Therefore, the objective of this study was to analyze U.S. consumers’ attitudes and willingness to pay (WTP) for beef based on color.

Materials and Methods: A mixed methods design, including a discrete choice experiment (DCE) and focus group discussions, was developed. The consumer survey included 3 sections: 1) color perception, 2) beef purchasing behavior and attitudes, and 3) a hypothetical DCE. The DCE included 3 product attributes: 1) beef color, 2) price, and 3) discount. Consumer preferences for steak color and price, as well as discount, were modeled using a mixed logit model (MLM). Based on the results of the consumer survey, 4 qualitative focus groups were conducted to assess consumers’ perceptions of beef color in more detail. All focus group sessions were audio-recorded and transcribed, and a qualitative content analysis was applied to evaluate the text material.

Results: Results of the MLM showed that participants would “purchase” one of the 2 beef steaks presented to them. Negative and significant coefficients for beef steak after 4,7, and 9 d of retail display demonstrated that consumers perceive, prefer, and see color nearly linearly across days. A steak with 0 d of retail display was the most preferred, whereas 9 d of retail display was the least preferred. Consumers’ WTP was negative for all days of retail display and decreased with an increase in discoloration. Respondents would spend $20 per lb. less for steak after 9 d of retail display compared to 0 d. Based on the text material of the focus group sessions, 4 main categories (i.e., “beef purchasing behavior, beef color perception, food and meat waste awareness, future buying decisions based on beef color”) and 11 sub-categories were identified. Focus group participants associated a bright cherry red color with freshness, beef quality, and eating satisfaction. Participants largely rejected discoloration and linked a brownish color to concerns about food safety, toughness, and dryness.

Conclusion: U.S. consumers perceive discrete differences in beef color and prefer color nearly linearly across days of retail display. Beef steak with 9 d of retail display is hardly marketable, even with significant discounts. Targeted marketing measures could be used to address beef buyers in order to ensure timely sales of beef products and thus reduce waste.

Funding Source: Funding was provided by the German Academic Exchange Service (DAAD) and the German Agricultural Society (DLG). This work was also partially supported by the USDA National Institute of Food and Agriculture, Multi-State Hatch project COL00276B (W5177).

Keywords: None

4 THE EFFECTS OF AGING TIME ON EATING QUALITY OF BICEPS FEMORIS STEAKS

M. J. Prester^1,*, L. M. Frink¹, S. L. Witberler¹, J. F. Legako², D. R. Woerner², R. K. Miller³, C. R. Kerth³, M. N. Nair⁴, J. M. Lancaster⁵, T. G. O’Quinn¹, ¹Animal Sciences & Industries, Kansas State University, Manhattan, Kansas, ²Animal & Food Sciences, Texas Tech University, Lubbock, Texas, ³Animal Science, Texas A&M University, College Station, Texas, ⁴Animal Science, Colorado State University, Fort Collins, Colorado, ⁵National Cattlemen’s Beef Assocation, Centennial, Colorado, United States *mason578@ksu.edu

Objectives: The objectives of this study were to identify consumer sensory, instrumental color, and objective tenderness traits of biceps femoris steaks from 8 different aging periods (14–70 d).

Materials and Methods: Beef sirloin top butt subprimal cuts (N = 80) were collected from a commercial beef processing facility. Subprimal cuts were then aged for 8 aging periods: 14, 28, 35, 42, 49, 56, 63, or 70 d at 2°C to 4°C. Once the aging period concluded, the biceps femoris and gluteus medius were separated, and 2.54-cm thick steaks were fabricated, frozen at −20°C, and stored for further analysis. Steaks were analyzed for instrumental raw and cooked color traits, instrumental tenderness, and consumer sensory analysis. Steaks were thawed for 24 h at 1°C to 4°C and then allowed a 30-min bloom period in ambient temperature prior to color evaluation. L*, a*, b* readings and spectral data were used to calculate hue angle, chroma, and percentage of oxymyoglobin (OMb), metmyoglobin (MMb), and deoxymoyglobin (DMb) on the steak surface. Steaks were cooked using a flat top griddle at 191°C to 68°C, then pulled and allowed to rise to a peak temperature of 71°C, with temperatures monitored using a thermocouple connected to an electronic reader. Once steaks reached peak temperature, they were sliced at a 45-degree angle to expose the internal surface, and after a 3-min bloom period, L*, a*, b* readings, spectral, and cook loss data were collected. After chilling steaks at 1°C to 4°C for 24 h, Warner-Bratzler shear force (WBSF) was measured using an INSTRON Model 5569 machine. For sensory analysis, steaks were divided into equal thirds, and consumers were provided an approximately 5-cm² sample for 5 samples representing different aging periods. Consumers (N = 96) evaluated overall tenderness, flavor, and juiciness liking on 1- to 10-point line scales and determined if the sample was acceptable for each trait (yes/no). Data were analyzed as a completely randomized design with aging period as fixed effect.

Results: There were no differences (P > 0.05) among aging treatments for overall, flavor, juiciness, and tenderness liking, and the percentage of samples rated acceptable for biceps femoris steaks; however, more than 90% of samples from each aging period were rated acceptable overall. Cooked steaks also showed no difference (P > 0.05) in cooking loss, WBSF, and cooked color readings among aging treatments. However, color data for raw steaks showed differences (P < 0.05), with a* and b* readings decreasing over time with the 14- and 28-d aged steaks having the highest (P < 0.05) readings for both measures and the 42- and 49-d aged steaks the lowest (P < 0.05) readings. Similarly, 14- and 28-d aged steaks had the lowest (P < 0.05) OMb percentage and highest (P < 0.05) DMb percentage of all aging periods, while 70-d aged steaks had the highest (P < 0.05) OMb percentage and the lowest DMb percentage.

Conclusion: Regardless of the aging period, consumers reported a high level of eating quality, with more than 90% of samples rated acceptable for biceps femoris steaks. No differences among aging periods were found for palatability and instrumental color readings of cooked samples, with the aging period having only minor impacts on raw color. These results indicate that the aging period has little impact on the quality traits of biceps femoris steaks.

Funding Source: Research coordinated by the National Cattlemen’s Beef Association, a contractor to the Beef Checkoff.

Keywords: beef, biceps femoris, consumer, flavor, palatability

5 THE EFFECTS OF AGING TIME ON THE EATING QUALITY OF SEMIMEMBRANOSUS STEAKS

L. M. Frink^1,*, S. L. Witberler¹, M. J. Prester¹, J. F. Legako², D. R. Woerner², R. K. Miller³, C. R. Kerth³, M. N. Nair⁴, J. M. Lancaster⁵, T. G. O’Quinn¹, ¹Animal Sciences and Industry, Kansas State University, Manhattan, Kansas, United States, ²Animal and Food Sciences, Texas Tech University, Lubbock, Texas, United States, ³Animal Science, Texas A&M University, College Station, Texas, United States, ⁴Animal Science, Colorado State University, Fort Collins, Colorado, United States, ⁵National Cattleman’s Beef Association, Centennial, Colorado, United States *lfrink@ksu.edu

Objectives: The objective of the study was to evaluate the palatability, instrumental tenderness, and objective color traits of semimembranosus steaks aged from 14 to 70 d.

Materials and Methods: Beef semimembranosus muscle (n = 10 cuts/aging time) was collected and aged as subprimal cuts for 14, 28, 35, 42, 49, 56, 63, or 70 d at 2°to 4°C in the absence of light. Cuts were fabricated into 2.54-cm steaks, frozen, and stored at −10°C until analyzed. One steak from each subprimal was allocated to tenderness and color evaluations, and a separate steak was assigned to sensory evaluation. After thawing, packages were opened and allowed a 30-min bloom period prior to measuring L*, a*, b*, and spectral data to calculate the hue angle, chroma, and percentage of oxymyoglobin (OMb), metmyoglobin (MMb), and deoxymyoglobin (DMb) from the surface of the steak. Steaks were cooked at 191°C on a flat top griddle to 68°C, then pulled off the grill and allowed to rise to a peak temperature of 71°C. Steaks were sliced at a 45° angle to expose the internal surface and allowed a 3-min bloom period before cooked color readings. Steaks were chilled at 1°to 4°C for 24 h before Warner-Bratzler shear force testing. For consumer sensory analysis, cooked steaks were divided into equal thirds for the consumers to evaluate. Consumers (N = 96) were asked to evaluate overall, flavor, tenderness, and juiciness liking on verbally anchored 1–10 line scales and asked if the sample was acceptable for each attribute. All data were analyzed as a completely randomized design with the aging period as a fixed effect.

Results: For consumer sensory analysis, there were no differences (P > 0.05) among aging periods for flavor and juiciness liking, and no differences (P > 0.05) in the percentage of samples rated acceptable for overall, flavor, and juiciness. Consumers rated 14 d aged steaks lower (P < 0.05) than 56 d steaks for overall liking and tenderness liking. There was a difference (P < 0.05) in the percentage of samples rated acceptable for tenderness, with a higher percentage of 70 d steaks rated acceptable than 14 d steaks. WBSF differed (P < 0.05) among aging periods, with 14 and 35 d steaks having higher shear values than 28, 42, 49, 56, 63, and 70 d steaks. For color analysis, no difference (P > 0.05) was found in raw hue angle or cooked L*, a*, b*, MMb, OMb, and DMb percentages, or cooked chroma, hue angle, and cooking loss. There was a difference (P < 0.05) for raw L*, with 14 and 28 d aged steaks having a lower (P < 0.05) L* value than 56 d. The raw a* and b* were different (P < 0.05), with 14 d steaks having a lower (P < 0.05) value for both when compared to 70 d. Also, 70 d steaks had a higher (P < 0.05) MMb percentage than 28 d steaks and a higher (P < 0.05) OMb percentage than both 49 and 56 d steaks. Additionally, 28 d steaks had a higher (P < 0.05) DMb percentage than 70 d steaks. The chroma value was higher (P < 0.05) for 14, 28, and 49 d steaks than for 63 and 70 d steaks.

Conclusion: Aging period had only minor impacts on many of the palatability traits of semimembranosus steaks, but steaks aged for only 14 d were tougher and less accepted by consumers in all attributes than steaks aged for longer periods. These results indicate that increased aging time for this muscle positively impacts tenderness without negatively impacting the other traits of flavor, juiciness, and overall liking.

Funding Source: Research coordinated by the National Cattlemen’s Beef Association, a contractor to the Beef Checkoff.

Keywords: beef, consumer, flavor, palatability, semimembranosus

6 CONCENTRATION OF ALPHA-GAL IN PROCESSED MEATS AND ITS POTENTIAL IMPACTS ON RURAL KANSAS COMMUNITIES

S. R. Hene ^1,*, J. T. Looper ¹, S. D. Lee ¹, Y. Park ², P. Brenes ³, M. D. Chao ¹, ¹Department of Animal Science & Industry, ²Department of Entomology, ³Department of Food, Nutrition, Dietetics and Health, Kansas State University, Manhattan, Kansas, United States *srhene@ksu.edu

Objectives: Alpha-gal syndrome (AGS) is an acquired sensitivity to galactose-alpha-1, 3-galactose (α-Gal) after a tick bite from the lone star tick (Amblyomma americanum). Affected individuals can experience a range of symptoms from mild itching to potentially fatal anaphylaxis after consuming red meat products. Recently, an increased number of AGS cases have been reported in Kansas (KS); however, little is known about the prevalence across the state. Furthermore, no work has been conducted to quantify the amount of α-Gal present in different meat products or to evaluate the potential impact of processing technique on α-Gal concentration. Thus, the two objectives for this study are 1) to gain a better understanding of the prevalence of AGS in rural KS communities and 2) to quantify the α-Gal concentration in various processed meat products to better understand the dosage required to elicit an immune response.

Materials and Methods: Incentivized surveys (160) were sent out to custom-exempt, state and federally inspected meat processors across the state. Survey questions aimed to understand AGS prevalence in KS and the respondents’ prior knowledge of AGS. To determine the α-Gal content of processed meats, 10 batches of 8 different processed meat products were purchased from a local grocer (n = 80). These samples consisted of pork bratwurst, fully cooked bacon, deli ham, beef hot dog, classic hot dog (mostly chicken, but with pork and beef added), beef summer sausage, beef jerky, and fully cooked beef patty. Whole muscle protein was extracted from each sample and separated by gel electrophoresis, transferred, and immunoblot against anti-α-Gal IgG1. Additionally, each gel included a reference sample of α-Gal conjugated-human serum albumin (HSA) with a known α-Gal content of 59.2 pmol. The concentration of α-Gal was determined as the ratio of the lane densities of the sample and the HSA reference multiplied by the known α-Gal content of HSA reference.

Results: Of the 160 surveys sent, 28 were returned. Survey results showed that 28.6% of respondents knew at least one person in their area with AGS. The geographical distribution of these cases was concentrated in the south central and southeastern regions of KS, which is consistent with the range of the lone star tick. Furthermore, only 53% of respondents knew that red meat allergy is related to tick bites, and 92.8% of them expressed that there is not enough public information about AGS. It was determined that pork brats and beef hot dogs had the highest concentration of α-Gal with 3.29 and 3.26 pmol of α-Gal/g of protein, respectively, followed by cooked beef patty with 2.76 pmol of α-Gal/g of protein, beef jerky at 2.45 pmol/g of protein, cooked bacon with 2.11 pmol/g of protein, beef summer sausage with 1.77 pmol/g of protein, deli ham with 1.37 pmol/g of protein, and with classic hot dog having the lowest concentration of α-Gal at 0.88 pmol/g of protein (P < 0.01).

Conclusion: Our preliminary survey results indicated a need for AGS education in KS rural communities and those located in geographically high-risk areas. Our data suggested that α-Gal content may be influenced by species, types of edible casing, and different processing techniques. However, further research is needed to quantify α-Gal content in lipid to better elucidate the influence of processing techniques as potential interventions to reduce the α-Gal content in meat products.

Keywords: α-Gal, alpha-gal syndrome, glycoprotein, processed meats

7 ANTIMICROBIAL RESISTANT BACTERIA IN ORGANIC, NATURAL, AND CONVENTIONAL GROUND BEEF FROM RETAIL SAMPLES COLLECTED IN THE UNITED STATES

R. L. Jimenez^1,*, J. Butts¹, M. X. Sanchez-Plata¹, M. M. Brashears¹, ¹ICFIE, Texas Tech University, Lubbock, Texas, United States *reagan.brashears@ttu.edu

Objectives: United States ground beef labeled as “natural” or “organic” is commonly perceived by the consumer as safer, and therefore likely to contain lower levels of antimicrobial resistant bacteria than conventionally processed ground beef. While there is a regulatory standard for “organic,” there is not one for “natural” products. The objective of this study was to survey and determine the levels of antimicrobial resistant bacteria in ground beef labelled as “natural,” “organic,” or “conventional” from retail samples collected in the United States. The hypothesis of this study is that no significant difference in levels of antibiotic resistance will be observed between the 3 sample varieties.

Materials and Methods: To meet the objectives of this study, a descriptive epidemiological study was conducted. A total of 36 ground beef samples were collected from retail settings that were labeled “natural,” “organic,” and with no label claim (conventional) to determine the presence of antibiotic resistant bacteria. Each sample was processed utilizing the Kiby Bauer Disc Diffusion methodology for antibiotic sensitivity against ampicillin, penicillin, novobiocin, and a control disc (no antibiotic). The zone of inhibition was measured to determine the resistance or susceptibility status of each sample to each antibiotic.

Results: Of the observed 36 samples, 14 displayed antimicrobial resistance to at least one antibiotic. The “natural” ground beef had the most resistance, with 6 of 9 samples having resistance to each of the utilized antibiotics. Of the organic meat, 66% displayed resistance to each ampicillin and penicillin, and 0% showed resistance to novobiocin. All the observed conventional meat samples showed resistance to ampicillin, 33% of samples were resistant to novobiocin, and all samples were susceptible to penicillin. Overall, the most resistance was observed to ampicillin, as 7 of the 9 ground beef samples tested against ampicillin showed resistance to this antibiotic.

Conclusion: The results of this study indicate no significant difference between the amount of antimicrobial resistant bacteria in organic, natural, and conventional ground beef obtained from retail samples in the United States. Antimicrobial resistance in animal products is thought to be associated with animal handling practices related to antibiotic use prior to harvest, and this study indicates that more research is needed to understand the emergence of resistance in the meat supply.

Funding Source: The funding for this project was provided by the International Center for Food Industry Excellence (ICFIE).

Keywords: antibiotic resistance, antimicrobial resistance, antimicrobials, ground beef, Salmonella

8 IMPACT OF RESIDUAL FEED INTAKE CLASSIFICATION ON MEAT QUALITY TRAITS OF NELLORE BULLS: “OBJECTIVE AND SENSORY ANALYSIS”

D. Alvarado Vesga^1,*, I. Alexandre Reis¹, R. C. Rodrigues¹, L. A. Chardulo Loyola^1,2, Y. T. Granja Salcedo³, P. H. Vilela Carvalho⁴, M. Narayanan Nair⁵, M. Coutinho⁶, G. Rovadoski⁶, W. A. Baldassini^1,2, ¹Animal Science, Sao Paulo State University, Jaboticabal, Brazil, ²Animal Science, Sao Paulo State University, Botucatu, Brazil, ³Animal Science, Colombian Agricultural Research Corporation, San Roque, Colombia, ⁴Animal Science, Ag Next Colorado State University, Fort Collins, Colorado, United States, ⁵Animal Science, Colorado State University, Fort Collins, Colorado, United States, ⁶Meat Quality, Brazil Beef Quality, Piracicaba, Brazil *c837286605@colostate.edu

Objectives: Improving feed efficiency (FE) can increase profitability and reduce the environmental impact of livestock production. However, the use of residual feed intake (RFI) could compromise beef quality. The objective of this study was to analyze objective and sensory meat quality traits of Nellore bulls feedlot finished and classified as efficient (low RFI) versus inefficient (high RFI).

Materials and Methods: One-hundred Nellore bulls (body weight [BW] = 323.7 ± 28.2 kg) were submitted to a FE test (21-d adaptation + 70-d data collection) to identify their RFI class. Daily dry matter intake (DMI) and average daily gain (ADG) were recorded using automatic feed bunkers and scales. RFI was computed using the DMI observed during the test period and regression coefficients derived from mid-test metabolic live weight (BW^0.75) and ADG. The animals were grouped into 2 categories: low RFI (<0.5 standard deviations below the mean; efficient) and high RFI (>0.5 standard deviations above the mean; inefficient). Subsequently, all animals were slaughtered on the same day, with average final body weight of 583.3 ± 31 kg. At deboning (24-h postmortem), carcass traits such as marbling score (MAR), ribeye area (REA), and backfat thickness (BFT) were evaluated. Longissimus thoracis samples from the low-RFI (n = 20) and high-RFI (n = 20) animals were collected for laboratory and sensory assays. Meat pH, color (L* = lightness, a* = redness, b* = yellowness), intramuscular lipid content (ILC), myofibrillar fragmentation index (%MFI), Warner-Bratzler shear force (WBSF), and cooking losses (CL) were evaluated. For sensory analysis, untrained consumers assigned scores from 0 to 100 on unstructured hedonic scales to the following meat quality traits using the Sensory Meat software v.1.6 (Brazil Beef Quality Ltd., Sao Paulo, Brazil): tenderness (TE), liking of flavor (FL), juiciness (JU), and overall acceptance (OA), which was based on MSA consumer testing. Data were submitted to the analysis of variance (ANOVA) using the F test. When differences were detected, the means were compared using the Tukey test at a significance level at (P < 0.05).

Results: Animals classified as Low-RFI had a decrease (P < 0.01) in DMI (−0.53 kg/d) compared to High-RFI animals. Moreover, Low-RFI animals had greater (P ≤ 0.04) REA (68.85 vs. 67.4 cm²), CL (28.7% vs. 25.7%), %MFI (31.35% vs. 28.20%), L* (38.26 vs. 36.18), and WBSF (7.53 vs. 7.02 kg) compared to High-RFI animals. However, Low-RFI animals had a decrease (P = 0.04) in %ILC (1.49% vs. 1.71%) and tended to decrease (P = 0.09) MAR (1.3 vs. 1.6) compared to the High-RFI group. Low-RFI animals had decreased (P < 0.02) JU (55.47 vs. 59.80) and OA (58.71 vs. 62.10) compared to high-RFI. However, in the sensory analysis, there was no difference (P = 0.10) between the low-RFI versus high-RFI groups in WBSF (55.61 vs. 58.89).

Conclusion: In general, the results of the present study indicate that grading Nellore bulls by RFI may result in differences in objective and sensory meat quality traits, particularly intramuscular fat content. Therefore, classifying animals with Low-RFI could affect meat quality traits and impact consumer acceptability.

Funding Source: The study was financed in part by CAPES–Finance Code 001. We also thank the Fundación para el Futuro de Colombia/COLFUTURO’s loan-scholarship program.

Keywords: beef cattle, feed efficiency, meat quality, sensory

9 LET’S SEE WHAT THEY ARE TALKING ABOUT: UTILIZING SPROUT SOCIAL’S LISTENING BOARDS TO EVALUATE PUBLIC OPINION OF MEAT RESIDUES

R. Lux^1,*, L. Fischer¹, ¹Agricultural Education and Communication, Texas Tech University, Lubbock, Texas, United States *rlux@ttu.edu

Objectives: One of the major obstacles for the meat industry is the spread of incorrect or false information. To properly understand the context and sentiment of shared information, the industry must learn to harness tools to understand diverse perspectives. Social media monitoring (e.g., Sprout Social) tools electronically monitor messages being posted about chosen topics, allowing communicators to analyze trends, sentiments, and opinions. This tool would help the industry get ahead of issues by monitoring the surrounding conversation and finding solutions to regulate how the topic needs to be addressed. The main objective of this study was to explore what topics consumers are discussing on social media regarding meat residues.

Materials and Methods: Keywords were selected based on their relationship with the topic, popular press, and prior literature. The chosen keywords include the following: meat residues, testing, beta-agonists, growth promoters, food safety, ractopamine, and clenbuterol. These served as targets for the software to find user-generated messages posted to Facebook, Twitter/X, Instagram, Reddit, and YouTube. Along with the copy evaluated in each post, we collected key metrics (e.g., engagement, reach, potential impressions). Data were collected from February 17 to March 28, 2024, by Sprout then exported to Microsoft Excel. The social media content was then analyzed using descriptive statistics outlined by Field (2013) in SPSS 29. The analysis was based on a codebook designed to collect information on topic, message type (original, share, or mention), and author information outlined in the researcher-developed codebook. The descriptive statistics were analyzed using frequency counts. Sprout’s listening feature collected 103 posts across social media platforms.

Results: After analyzing the posts, 14 topics were discovered: company promotion, cooking, degree options, diet preferences, fake meat, feed additives, food safety, growth promoters, imports, meat processing, policy, recall, research, and travel. These posts came from 87 unique authors and had an average of 12,947 followers and 2 engagements per post. The overall sentiment detected by Sprout was 64% negative. Together, these posts had over 1,259,000 total potential impressions, or the possible number of times users could have seen the post.

Conclusion: After evaluating each post’s content, we found the conversation pool is shallow but wide—with diverse topics. Companies and consumers use social media to discuss issues and ideas of the industry every day. We recommend practitioners and academics begin taking more advantage of the potential reach social media has to communicate about meat science. Sprout’s listening capabilities allow researchers to collect publicly shared posts. This listening board was designed to collect data on what information has been posted on meat residues and food safety, a goal we achieved. Using this technology for research projects, such as this one, can be useful in understanding public opinion toward specific topics, like meat science, significantly cutting down data collection time and allowing for more detailed analysis of public opinion. While this study was descriptive in nature, future studies could utilize this tool to provide comparisons between topics, such as what is regarded as “fake” or misinformation versus credible. Findings from this research may inform more effective future science communication to debunk myths about the meat science industry.

Keywords: communication, consumer opinion, food safety, meat residues, social media

10 THE EFFECTS OF AGING TIME ON EATING QUALITY OF GLUTEUS MEDIUS STEAKS

S. L. Witberler^1,*, L. M. Frink¹, M. J. Prester¹, J. F. Legako², D. R. Woerner², R. K. Miller³, C. R. Kerth³, M. N. Nair⁴, J. M. Lancaster⁵, T. G. O’Quinn¹, ¹Animal Sciences and Industry, Kansas State University, Manhattan, Kansas, United States, ²Animal and Food Sciences, Texas Tech University, Lubbock, Texas, United States ³Animal Science, Texas A&M University, College Station, United States, ⁴Animal Science, Colorado State University, Fort Collins, United States, ⁵National Cattlemen’s Beef Assocation, Centennial, Colorado, United States *switberler26@ksu.edu

Objectives: The objective of this study was to determine the palatability characteristics and color traits of gluteus medius steaks aged 14, 28, 35, 42, 49, 56, 63, and 70 d.

Materials and Methods: Beef top sirloin butts (N = 80) were collected from a commercial packing plant 48 h postmortem and aged for 14, 28, 35, 42, 49, 56, 63, or 70 d at 2 to 4°C in vacuum packaging as subprimals. Once subprimals reached their designated age time, the gluteus medius and biceps femoris were separated and fabricated into 2.54 cm thick steaks, packaged, frozen at −20°C, and stored. Steaks were designated for consumer sensory panels, Warner-Bratzler shear force (WBSF), and raw and cooked color evaluation. Prior to all analyses, steaks were thawed for 24 h at 1 to 4°C. Steaks for shear force were removed from the package and allowed approximately 30 min to bloom before raw L*, a*, b*, and spectral data were collected using a HunterLab MiniScan spectrophotometer (Illuminant A, 10° observer, 2.54 cm aperture). These data were used to calculate percent deoxymyoglobin (DMb), oxymyoglobin (OMb), metmyoglobin (MMb), chroma, and hue angle according to the AMSA Guidelines for Meat Color Measurement. Steaks were cooked on a flat top griddle to an internal peak temperature of 71°C, sliced at a 45° angle parallel to the muscle fiber orientation, and allowed 3 min bloom time before measuring internal cooked color. Samples were cooled at 1 to 4°C for 24 h before WBSF evaluation. Steaks designated for consumer sensory panels were cooked to an internal peak temperature of 71°C, sliced into 3 approximately 5 cm × 5 cm pieces, and served to consumers. Consumers (N = 96) evaluated 5 samples of varying age times for overall liking, juiciness liking, tenderness liking, and flavor liking on 10-point line scale with 1 being dislike extremely and 10 being like extremely. Additionally, each sample was evaluated for acceptability of each trait (acceptable/unacceptable).

Results: Consumers found no difference (P > 0.05) among aging treatments for overall, juiciness, tenderness, or flavor liking. While there were no differences (P > 0.05) in the percentage of samples rated acceptable for overall, juiciness, tenderness, or flavor, all treatments had at least 81% of samples rated acceptable overall by consumers. Furthermore, there were no differences (P > 0.05) in cooking loss, cooked L*, a*, b*, DMb, OMb, MMb, chroma, or hue angle among treatments. Steaks aged 14 d had greater WBSF values than all other treatments, and 63 and 70 d were more tender (P < 0.05) than samples aged 42 d or less. While there were differences found in raw color, there were few apparent trends. Steaks aged 14, 49, and 56 d were redder (P < 0.05) than 63 and 70 d steaks. Steaks aged 14 d were darker (P < 0.05) than steaks aged 49 d or more. Though there were no differences (P > 0.05) in raw calculated MMb, DMb was greater (P < 0.05) in 14, 35, 49, and 56 d steaks than 63 and 70 d. Additionally, OMb was greater (P < 0.05) in 63 d than 14, 35, 42, and 56 d.

Conclusion: Aging gluteus medius steaks from 14 to 70 d had no impact on the palatability traits evaluated by consumers. However, increased aging time was associated with improved tenderness and steaks that were lighter in color. These results indicate that extended aging time has only limited impact on palatability and color characteristics of steaks from the gluteus medius.

Funding Source: This research was coordinated by the National Cattlemen’s Beef Association, a contributor to the Beef Checkoff.

Keywords: beef, consumer, flavor, gluteus medius, palatability

Education and Extension Tools

11 IMPACT OF THE NEBRASKA YOUTH BEEF LEADERSHIP SYMPOSIUM

B. A. Reiling¹, B. M. Garcia^1,*, G. Sullivan¹, A. Benes¹, A. Raymond¹, B. French¹, J. Wicks¹, K. Stanke², ¹Animal Science, ²Statistics, University of Nebraska-Lincoln, Lincoln, Nebraska, United States *breiling2@unl.edu

Objectives: The Nebraska Youth Beef Leadership Symposium (NYBLS) was established in 2004 for high school youth to (1) encourage pursuit of careers in the beef industry, (2) better understand importance of value-added beef products, (3) develop confidence in educating consumers, and (4) enhance communication, interpersonal skills, leadership, and teamwork. To date, NYBLS boasts 809 alumni. Since 2009, the focal project of NYBLS has been to engage youth in a culinary challenge. By asking youth to develop a unique retail product for potential sale, youth learn about meat science, beef product utilization, and consumer perceptions. Upon developing business and marketing plans, they learn about finance and business management. Working in teams, youth practice interpersonal skills learning the impact of leadership, communication, and collaboration. The specific objective of this study was to analyze post-program evaluations, amalgamated across years to determine sustained effectiveness and impact of NYBLS on youth education and leadership development in the beef industry.

Materials and Methods: A voluntary post-program evaluation asked participants (2009–2022) to rate their agreement with several statements before and after NYBLS. Responses were aggregated across years. Survey response number (n = 176–426) varies by question as some questions were not asked every year. Options for each question were a partially anchored, ordered series from 1 (strongly disagree) to 5 (strongly agree). Confidence intervals (95%) were formed for the percentage of positive responses using the Agresti-Coull approximate binomial method, and significant differences were calculated using McNemar’s Chi-squared test for paired proportions with α = 0.05.

Results: The percentage of positive responses for survey statements is shown in Table 1. Post-program evaluations indicate NYBLS participation helped youth better understand beef production, beef as a meat product, consumer trends, and related career opportunities. In addition, NYBLS reinforces the importance of communication, teamwork, and leadership development. With an average score of 4.73 ± 0.61 (n = 424), more than 95% of NYBLS participants would recommend this symposium to other youth.

Conclusion: NYBLS provides an example of how an interactive, hands-on symposium can not only stimulate the passion of youth for agriculture and allied industries but encourage engagement of consumers while enhancing leadership skills.

Keywords: beef, leadership, youth

12 YOUTH LIVESTOCK EXHIBITORS EXPERIENCE SAMPLING LAMB, GOAT, AND BEEF

J. B. Van Buren^1,*, B. S. Epperson¹, M. N. Wootton¹, C. R. Shaw¹, J. A. Nasados¹, J. B. Glaze¹, P. D. Bass¹, M. J. Colle¹, ¹Animal, Veterinary, and Food Sciences, University of Idaho, Moscow, Idaho, United States *jvanburen@uidaho.edu

Objectives: While lamb and goat production has increased in popularity commercially and with youth livestock exhibitors, the average consumption of lamb in the U.S. is less than one pound per year, and goat consumption is so low that it is not recorded. Consumption of these meats is likely higher than average within farming and ranching populations, but previous Extension programming showed that a limited number of youth livestock exhibitors had previously sampled lamb or goat. The objectives of the study were to (1) evaluate meat consumption in youth livestock exhibitors and (2) evaluate youth acceptability of different proteins.

Materials and Methods: This study was classified as exempt by the University of Idaho Institutional Review Board. During the meat science sessions (4 rotations) at the 2023 Youth Sheep and Goat Field Day, 71 youth (ages 7 to 17) completed the taste panel with parental/guardian consent. Youth were asked demographic questions: previous meat consumption (beef/chicken/goat/lamb/pork), favorite meat (beef/chicken/goat/lamb/pork), species exhibited (beef/goat/poultry/sheep/swine), and age. Each youth was served one sample of lamb, beef, and goat. Beef bone-in ribeye steaks, lamb chops, and goat chops were cooked to an internal temperature of 71°C on a two-sided electric grill. Samples were served one at a time in individual sample cups. Following sampling youth were asked to identify the species (beef/goat/lamb), likeness of the sample (1-dislike extremely; 10-like extremely), and willingness to eat again (no/unsure/yes). Demographic data were analyzed in Microsoft Excel. Sampling likeness data were analyzed using a mixed model analysis of variance using SAS 9.4. The results of willingness to eat again were converted into scores of 1 = yes, 0 = no/unsure, and whether the participant correctly identified the species was converted into scores of 1 = yes, 0 = no. Binomial data were analyzed using a generalized linear model in SAS. Species treatment was assumed as a fixed effect. Significance was determined at P < 0.05.

Results: When asked which specie(s) participants exhibited, most exhibited goats, followed by sheep, beef, poultry, and swine. Nearly all participants had sampled beef, chicken, and pork previously, but less than half had sampled lamb, and only a quarter had sampled goat. This is likely higher than the average population, but it validated a knowledge gap in the youth exhibitors regarding the final product of their animals. When asked their favorite meat, nearly half the youth selected beef, followed by chicken, pork, goat, and lastly lamb. Youth consistently incorrectly guessed which species they were consuming (P = 0.08), showing an inability to distinguish between the proteins. Youth preferred the lamb sample to the beef and goat samples (P = 0.038). However, all species had an average likeness within 5 to 7, which may be due to the lack of seasoning on the samples unlike how a youth would consume meat at home or at a restaurant. Youth were also more willing to eat the lamb sample again as compared to the beef and goat samples (P = 0.028).

Conclusion: Previously, youth livestock exhibitors had minimal exposure to goat and lamb, and preferred beef. Due to the blind sampling, youth were able to separate previous perceptions from the evaluation of the meats and expand their palate to enjoy new protein sources, with lamb being the favored sample.

Funding Source: We gratefully acknowledge financial support from the Idaho Ag Experiment Station.

Keywords: consumption, livestock, meat, youth

13 PERCEPTIONS OF THE MEAT PROCESSING INDUSTRY: PRE- AND POST-360-DEGREE IMMERSIVE VIDEO EXPERIENCE OF THE MEAT CUTTING PROCESS

T. Chandrasekera¹, M. Pfeiffer^2,*, A. Jayadas¹, ¹Design and Merchandising, ²Animal and Food Science, Oklahoma State University, Stillwater, Oklahoma, United States *aditya.jayadas@gmail.com

Objectives: This study aimed to evaluate the impact of a 360-degree immersive video on changing perceptions of the meat processing industry among agriculture students. It sought to determine whether exposure to the entire meat cutting process via immersive video could alter students’ views on the attractiveness and engagement of careers in this sector.

Materials and Methods: Twenty undergraduate students at a Midwestern university, majoring in agriculture business, animal science, or food science, participated in the study. Their average age was 20.33 ± 2.76 years, with a gender distribution of 10 females, 9 males, and 1 participant who opted not to disclose their gender. Participants watched a comprehensive 360-degree video covering all stages from stunning to packaging in the meat processing workflow. They then assessed their perceptions of the industry using a Likert scale ranging from 1 (very negative) to 5 (very positive) in terms of enjoyment, fun, interest, and attention. A one-tailed paired t-test was conducted to analyze perceptual changes, with a significance threshold set at 0.05.

Results: Despite initial positive expectations about the industry being enjoyable, fun, interesting, and attention-grabbing, the statistical analysis indicated no significant change in perceptions post-video exposure (enjoyment: P = 0.31; fun: P = 0.31; interesting: P = 0.06; attention: P = 0.33). This outcome suggests that the participants’ prior familiarity with agricultural practices may have buffered any potential shifts in perception.

Conclusion: The findings suggest that 360-degree immersive videos have limited effectiveness in altering perceptions among students already acquainted with agricultural practices. This indicates that immersive recruitment and educational tools might be more impactful when targeted at individuals without prior exposure to the field. Meat processing facilities need to consider the baseline industry knowledge of their target audience when designing such tools. Future research should investigate the effectiveness of immersive technologies on a more diverse audience to enhance the specificity and efficacy of recruitment strategies in the meat processing industry.

Funding Source: College of Education and Human Sciences, Oklahoma State University.

Keywords: 360-degree immersive video, attention, enjoyment, interest, meat cutting and processing

14 ENHANCING SKILL ACQUISITION IN THE MEAT INDUSTRY: IMPACT OF VIRTUAL REALITY TRAINING ON PERCEIVED MEAT CUTTING COMPETENCE AND USEFULNESS OF VIRTUAL REALITY–BASED SKILLS TRAINING TO CUT MEAT

M. Pfeiffer¹, A. Jayadas^2,*, T. Chandrasekera², ¹Animal and Food Science, ²Design and Merchandising, Oklahoma State University, Stillwater, Oklahoma, United States *aditya.jayadas@gmail.com

Objectives: This study aimed to evaluate the efficacy of virtual reality (VR) training in improving perceived competence in meat cutting tasks and assessing the perceived usefulness of VR-based skills training within the meat processing industry. The objective was to determine whether VR can serve as a cost-effective and engaging alternative to traditional training methods amid ongoing labor shortages.

Materials and Methods: Participants included 20 undergraduate students from a Midwestern university majoring in agriculture education, animal science, or food science. The average age of participants was 20.42 ± 2.83 years. Using VR headsets, participants engaged in a simulated task of cutting primal cuts on a virtual beef carcass. A pre- and post-intervention survey measured perceived competence and usefulness of the training on a 5-point Likert scale. A one-tailed paired t-test was utilized to analyze the data, with significance levels set at 0.05.

Results: The study revealed a statistically significant improvement in the perceived competence of participants to cut meat (P = 0.005) and in their perception of the usefulness of VR-based training (P = 0.04). These findings suggest that VR training effectively enhances both the skills and the appreciation of the training method among participants.

Conclusion: VR training demonstrates considerable potential in addressing training challenges in the meat processing industry by reducing time and costs associated with traditional methods. The increased perceived competence and usefulness point towards VR’s capability to provide engaging and effective training, making it a viable solution for mitigating labor shortages. Further research should investigate the long-term effects of VR training on skill retention and compare it to traditional training outcomes to fully understand VR’s impact and optimize its implementation.

Funding Source: College of Education and Human Sciences, Oklahoma State University

Keywords: meat cutting and processing, perceived competence to cut meat, usefulness of virtual reality training, virtual reality

15 PREPARING STUDENTS FOR THE SPANISH-SPEAKING WORKFORCE IN NEBRASKA

L. G. Venzor^1,*, G. A. Sullivan¹, L. Karr¹, ¹Animal Science, University of Nebraska-Lincoln, Lincoln, Nebraska, United States *lvenzor3@huskers.unl.edu

Objectives: According to the National Agricultural Workers Survey (2019–2020), 68% of US farm workers are foreign-born, with 62% reporting Spanish as their dominant language. Borys and Ingran (2008) reported that the number of Spanish-speaking workers continues to grow as they become critical in many segments of agriculture. With 1 in 4 jobs in Nebraska relating to agriculture (USDA NASS, 2017), the need to prepare the next generation of graduates for a Spanish-speaking workforce is of utmost importance. In the state of Nebraska, Hispanics accounted for 56% of the population growth between 2000 and 2017, primarily driven by growth in the meat and cattle industries. The objective of this curriculum development was to provide a Spanish in Agriculture course to prepare non–Spanish-speaking students for industry through basic communication, agriculture terminology, and cultural awareness training.

Materials and Methods: The Spanish in Agriculture class was offered as a zero-credit course, once a week for an hour and a half. Students were evaluated at midterm based on ability to teach an agriculture-focused skill in Spanish and execution of an interview of a Spanish speaker at course completion. Those who fulfilled the requirements of the course received a digital badge. Students were asked to complete an anonymous post-course survey to evaluate learning outcomes and confidence of resulting Spanish application. The objectives of the course and overall satisfaction were evaluated using a 5-pt Likert scale (0: fully disagree; 4: fully agree). Students were also asked a series of yes or no questions with further explanation requested for either answer. Nineteen (19) students over 2 semesters were surveyed, where 13 were undergrads and 6 were graduate students. Majors represented include Animal Science, Agricultural Economics, Integrated Sciences, Water Science, and Grassland Systems.

Results: All student survey respondents reported that the Spanish in Agriculture course increased their Hispanic cultural awareness. Seventy-six percent (76%) of students reported that they were comfortable or very comfortable with agricultural terminology at course completion. Additionally, survey results indicated that 81% of students were satisfied or very satisfied with what they learned in the course. When asked if they felt comfortable with basic sentence structure or giving and understanding basic instructions in conversational Spanish, 63% and 57.9% of students reported being comfortable or very comfortable, respectively. Course and instructor satisfaction was notably high with 78.9% and 94.7% reporting to be satisfied or very satisfied, respectively. Furthermore, all but 2 students surveyed reported that the course descriptions matched their learning outcomes.

Conclusion: Overall, students reported being satisfied with the course, level of work, resources provided, and with the instructor. Students that reported being less satisfied were Water Science majors. This may be attributed to the course being focused on the agricultural industry in Nebraska. Past students of the course have also reported using skills learned in this course in the dairy and swine industries, along with high school vocational agriculture lessons. Further work surveying course alumni would be beneficial to quantify the effect of this Spanish in Agriculture course in the respective careers of past students.

Keywords: agriculture, language learning, Spanish, workforce

16 ACADEMIC MOTIVATION AND GOAL ORIENTATION OF RURAL VERSUS URBAN STUDENTS IN ANIMAL SCIENCE AT THE UNIVERSITY OF NEBRASKA-LINCOLN

L. G. Venzor^1,*, J. Jeffries², B. L. Weinandt¹, G. A. Sullivan¹, L. Karr¹, ¹Animal Science, ²Educational Psychology, University of Nebraska-Lincoln, Lincoln, Nebraska, United States *lvenzor3@huskers.unl.edu

Objectives: The Department of Animal Science at the University of Nebraska-Lincoln (UNL) has seen an increased proportion of urban students due in part to the growth of the pre-veterinary option. The purpose of this study is to evaluate the academic motivation of changing student demographics in animal science and explore the potential correlation between goal orientation and geographical origin. The 2x2 goal orientation framework (Elliot & McGregor, 2001) is divided into mastery and performance goal orientations between 2 dimensions, approach, and avoidance. Mastery goal orientation is exhibited by the desire to learn new skills and increase competence, while performance goal orientation is based on competition, recognition, and demonstration of superiority. Approach dimensions focus on positive outcomes and are considered adaptive while avoidance dimensions focus on avoiding negative outcomes and are maladaptive. Previous research has linked adaptive goal orientations (Mastery Approach, Performance Approach) to higher student achievement and engagement.

Materials and Methods: A Qualtrics survey was distributed via university email and Canvas announcement to determine categorical demographics (gender, race, ethnicity, classification, major, option, and high school location) and evaluate goal orientation. Goal orientation questions (12), based on the 2x2 paradigm, aimed to evaluate the 4 types of achievement goal theories, Mastery Approach, Mastery Avoidance, Performance Approach, and Performance Avoidance based on a 7-point scale: 1 “not at all true of me” to 7 “very true of me”. Classifications of geographic origin used USDA ERS Rural-Urban Continuum Codes, which distinguish counties by population, adjacency, and degree of urbanization. Eligible respondents (n = 92) were 17 years or older and were enrolled or completed ASCI 95–Animal Science Orientation after 2020. Data were analyzed using the linear model regression procedure in R Studio 2023.12.1.

Results: Based on the Rural Urban Continuum codes, 41.8% of respondents originated from rural counties and 58.2% from urban or suburban counties across 14 states (n = 86). An overwhelming 89.1% of respondents identified as White, followed by Hispanic (6.5%), African American (2.2%), and Asian (2.2%). Female-identifying students accounted for 75% of respondents, with the remaining identified as 22.8% male and 2.2% non-binary or other. There were no correlations between Mastery Avoidance or Performance Avoidance and geographic classification (P = 0.98, P = 0.59, respectively), gender (P = 0.13, P = 0.19), or race and ethnicity (P = 0.44, P = 0.13). Students who were from rural counties were positively correlated with Performance Approach goal orientations (P = 0.016). Non-white students were negatively correlated with Mastery Approach (P = 0.018) but were not positively correlated with any other goal orientation.

Conclusion: These data indicate that respondents are not correlated with maladaptive goals. Furthermore, rural county respondents’ correlation with Performance Approach indicates that these students were motivated by outperforming and overachieving. These survey results indicate that opportunities to compete and be recognized could help motivate students, specifically from rural counites. Further research with larger sample sizes needs to be conducted to determine achievement goal orientations for urban students.

Keywords: animal science, motivation, rural, urban

17 STUDENT WORKFORCE DEVELOPMENT PROGRAM PROMOTING EXPERIENTIAL LEARNING FOR THE MEAT AND POULTRY INDUSTRY, COHORT ONE

L. A. Kinman^1,*, L. G. Garcia², M. M. Franklin¹, T. N. Tolen¹, ¹Department of Agriculture, Nutrition, and Human Ecology, Prairie View A&M University, Prairie View, Texas, United States, ²Department of Animal Science, Ohio State University, Columbus, Ohio, United States *lakinman@pvamu.edu

Objectives: The need to provide food to a growing population has resulted in a shortage of skilled laborers in the meat and poultry industry. Historically, these roles have been filled by immigrants, but there is a need to attract more skilled American workers, especially for smaller processing facilities. Introducing meat science programs could help expose students to career opportunities in this field, but these programs struggle to recruit students, leading to a shortage of qualified workers in the industry. Therefore, the objectives of this study were to provide a workforce development program for high school students on meat processing procedures at Prairie View A&M University (PVAMU) and develop an extension-educational experience designed to enhance work-readiness skills for PVAMU undergraduate students with Ohio State University–Meat Science Extension (OSUMSE).

Materials and Methods: The program was designed in 2 components: 1) PVAMU Meat Master Training Program, a week-long residential program that involved hands-on training; and 2) Experiential learning at OSUMSE. Program 1 covered topics in food safety, carcass fabrication, and processed meat development to high school students (n = 4). Participants were given a Qualtrics questionnaire on the first day to measure their knowledge and confidence to perfom before the program (pre-), and at the end they answered the same questions related to knowledge and confidence (post-). Program 2 involved sending PVAMU undergraduate students (n = 4) to The Ohio State University to work with the extension meat specialist for 3 wk in a summer residential program. Participants developed carcass evaluation skills, as well as communication and leadership proficiencies. Participants were exposed to Ohio county fair carcass shows, national extension programs, and on-farm animal processing. The overall focus was to understand how livestock management practices affect meat quality and safety. Additionally, students were exposed to leadership and STEM skills in the meat industry by working with Ohio communities. In years 2 and 3, a pre-exam and post-exam will be administered to participants.

Results: Participants of the PVAMU Meat Master Training Program (Program 1) demonstrated a significant increase in knowledge scores related to food safety techniques (P = 0.04), general carcass processing techiques (P < 0.05), and significant increase in confidence scores realted to general carcass processing techiques (P = 0.01). Attendees of the Experiential Learning Program at OSUMSE (Program 2) exhibited progress in knowledge and enhanced communication skills in conveying information about carcass evaluation and its significance to the meat industry, as determined through anecdotal evidence.

Conclusion: The PVAMU Meat Master Training Program and the Ohio State University Meat Science Extension Program were effective in developing workforce readiness skills for high school and undergraduate students, respectively. These programs, which incorporate non-traditional practices by exposing students to universities with different philosophies and resources, can serve as models for other institutions seeking to address the shortage of skilled laborers in the meat and poultry industry. Collaboration between universities is a critical component in strengthening the future of agriculture by enhancing the skills of future employees, our students.

Funding Source: USDA-NIFA-1890 CBG

Keywords: experiential learning, higher education, meat industry, meat science extension, workforce development

18 EVALUATION OF STUDENT LITERACY IN LOWER LEVEL MEAT SCIENCE–BASED COURSES VIA VIDEO METHODOLOGY

A. Lake^1,*, M. A. Scott¹, K. Harr¹, G. G. Mafi¹, R. Ramanathan¹, M. M. Pfeiffer¹, ¹Department of Animal and Food Sciences, Oklahoma State University, Stillwater, Oklahoma, United States *madelyn.scott@okstate.edu

Objectives: In-person lecture delivery methods are historically regarded as the most effective instruction method for course success. Determining students’ retention of the information relayed through course lecture is critical to overall success and educational development. Therefore, the study objective was to quantify the understanding of important scientific terminology and concepts among students in meat science courses. This study evaluated the knowledge gained over a semester among 2 courses.

Materials and Methods: Students were selected on a voluntary basis to participate in the meat science literacy study. The students were either enrolled in the Animal Science 2253 “Meat and Carcass Evaluation” (evaluation of carcasses and wholesale cuts of beef, pork, and lamb) or ANSI 2233 “The Meat We Eat” (overview of all animal, poultry, and fish protein sources used for human consumption, but focusing on red meat.) Students were individually asked a series of questions prior to course instruction beginning. Answers were recorded by video, and participants were given a random code. Questions asked of students in 2233: What is meat science?; Name one job associated with meat science?; Is organic, all-natural labeled meat healthier and better for you?; Does meat need to be inspected before it enters the supply chain?; What are processed meats? If you know, give an example.; What is meat’s role in the diet?; What is cutability and/or yield? Why is it important?; What temperature does the USDA recommend you cook most meat and poultry products to?; Give some examples of meat packaging.; What is HACCP? Why is it important? Questions asked of students in 2253: What is cutability?; What is marbling? Does it impact meat palatability?; What are some ways in which value is assessed in the meat industry? Example, how are carcasses priced?; Do genetics influence meat quality?; What are some meat quality defects that can occur because of stress on the animal?; In a typical large scale beef packing plant where is the ribeye area, fat thickness, and marbling score determined on the carcass?; What color is desired in fresh beef, pork, and lamb?; Give some examples of branded meat programs.; Give some examples of careers in the meat industry.; Why is castration important and does it impact meat eating quality? The students (n = 10) were asked the aforementioned questions prior to course instruction, and again following the conclusion of the course. Qualitative responses from both sessions were recorded and compared to a codebook with previously determined key words to identify students’ understanding of course concepts. Responses were coded (correct = 1, incorrect = 0) for instances of keywords. The codebook was evaluated by 3 trained officials. Frequency of keyword usage in responses were calculated using the FREQ procedure of SAS.

Results: Of the total questions asked of ANSI 2233, 64% of the questions were answered correctly before the course. When evaluating the answers to the same questions following the course, an increase in correct answers was observed, as 86% were correct. In ANSI 2253, 52% of total questions asked were answered correctly. Upon completion of the course, 82% of questions were answered correctly.

Conclusion: In conclusion, course instruction is critical to better educate and improve the fundamental understanding of complex meat science concepts in students. Future research could evaluate the relationship between students’ retention and final grades in order to predict course success.

Keywords: literacy, meat science, student

19 MERGING MEAT SCIENCE AND A LEAN SIX SIGMA APPROACH TO IMPROVE FURTHER PROCESSING EFFICIENCY USING BURGER MANUFACTURING AS A MODEL PROCESS: A CASE STUDY

L. Guzman^1,*, A. Morey¹, ¹Poultry Science, Auburn University, Auburn, Alabama, United States *ljg0025@auburn.edu

Objectives: The production efficiency of a further processing plant significantly relies on meat quality, equipment, and operational procedures. This study explores the application of Lean Six Sigma (LSS), an operations management tool designed to enhance the efficiency of beef meat processing plants. This study examines whether LSS, specifically through the DMAIC (Define, Measure, Analyze, Improve, Control) and Kaizen methodologies, can enhance operational stability and enable the plant to achieve its production targets. By conducting a detailed case study and analyzing current processes, the research aimed to determine if these methodologies can effectively identify and reduce sources of shrinkage and waste within the production line. The primary focus was to assess the impact of LSS on process improvement and operational efficiency.

Materials and Methods: This case study employed a systematic in-plant analysis across 4 key production stages: receiving room scales, combo dumping station, water misting process, and empty box tare weights. This involved calibrations, operational training, purge volume analysis, water-nozzle efficiency assessments, and standardizing box tare weights for packaging. Data were collected on 345 meat combos of receiving for scale variance, 145 combos in dumping processes to measure waste and drip loss, 372 burger patties (45.5 g, 76% Lean, 24% Fat) to assess water misting operations, and 1200 cardboard boxes for weight measurements. Utilizing Lean methodologies—such as DMAIC, Kaizen, Poka-Yoke, and 5S—which focus on improving process efficiency by eliminating waste alongside Statistical Process Controls (SPC) and linear regression models via Minitab, the research identified significant efficiency bottlenecks.

Results: Key findings revealed a significant variance in the weights of received meat combos, which directly impacted inventory accuracy. Additionally, at the combo dumping station, purge drip loss showed a correlation with the lean percentage, meat age, and purge volume, highlighting critical factors affecting product loss. Notably, 38% of patties experienced weight loss post-freezing, attributed to water misting inefficiencies, leading to considerable shrinkage. Furthermore, the research determined a standardized box tare weight of 0.92 lb, a reduction of 0.06 lb per box, pinpointing another crucial source of shrinkage in the packaging area.

Conclusion: These results underscore the critical role of LSS methodologies in pinpointing and reducing inefficiencies within beef meat processing plants. The implications of these findings suggest that a convergent approach, incorporating both DMAIC and Kaizen methodologies, significantly improves production efficiencies by addressing and mitigating process variances and waste. Moreover, the results promise notable financial benefits through the optimization of resources and the ruthless elimination of waste, underscoring the potential for substantial cost savings alongside efficiency gains. This research contributes to the operational management field by demonstrating the practical application and benefits of LSS in the food processing industry, proposing a model for future process improvement endeavors that enhances operational performance and ensures economic advantage.

Keywords: continuous improvement, food processing industry, further processing, Lean Six Sigma, process optimization

20 INFLUENCE OF VEGETATIVE DIVERSITY DURING THE STOCKER PHASE ON CARCASS CHARACTERISTICS AND ECONOMIC RETURNS OF BEEF STEERS

S. E. Borders^1,*, J. R. Brennan¹, C. E. Bakker¹, K. R. Underwood¹, J. K. Grubbs¹, J. R. Jaeger¹, K. C. Olson¹, A. D. Blair¹, ¹Department of Animal Science, South Dakota State University, Brookings, South Dakota, United States *sydni.borders@sdstate.edu

Objectives: Stocker cattle can be managed in multiple grazing environments (variable range health, forage quality and quantity), which could impact subsequent performance and carcass attributes. The objective of this study was to determine the influence of different grazing intensities (light, moderate, heavy) on the carcass characteristics and economic returns of beef steers.

Materials and Methods: A long-term grazing study was conducted on 6 different pastures as a randomized complete block with 3 levels of grazing intensity (light = 0.32 AUM/acre, moderate = 0.40 AUM/acre, and heavy = 0.72 AUM/acre) in 2 replicate blocks. Pastures have been similarly stocked since 1942 creating 3 distinct plant communities of rangeland vegetation, ranging from cool-season dominant mid-grasses (lightly grazed) to warm-season dominant shortgrasses (heavily grazed). Forage production was 1276, 1136, and 963 ± 80 kg/ha for light, moderate, and heavy pastures, respectively. To determine the influence of forage diversity created by varying levels of grazing intensity on carcass outcomes, yearling steers (n = 134, 116, and 131, in 2020, 2021, and 2022, respectively) were stratified by body weight to 6 groups and randomly assigned to pastures. At the completion of the stocker phase, steers were weighed and transported to a feedlot where they maintained their pasture groups (one feedlot pen allotted per pasture). At harvest hot carcass weight (HCW), 12^th rib backfat thickness, ribeye area (REA), marbling score, and USDA Quality and Yield grades were recorded. Production (HCW/hectare) and economic return per carcass and per hectare were calculated. Data were analyzed as a randomized complete block design using mixed model procedures. The fixed effects of stocking rate, year, and their interaction were included.

Results: Stocking rate treatment and year did not interact (P > 0.05) for live weight or carcass measurements. Body weight at the end of the stocker phase did not differ across treatments (P > 0.05), but steers were lighter (P < 0.001) in 2022 than in 2020 and 2021. Body weight produced per hectare at the end of the stocker phase differed (P < 0.01) among all 3 treatments with heavy stocking rate yielding the greatest and light stocking rate yielding the least. Stocking rate treatment did not influence (P > 0.05) carcass traits or total carcass value ($/carcass). Steers had greater (P < 0.001) HCW, backfat, yield grade, and marbling scores in 2021 compared to 2020 and 2022, while REA was similar (P > 0.05) in 2021 and 2022 but larger (P < 0.05) than in 2020. Carcass value in 2020 was less (P < 0.001) than 2021 and 2022, which did not differ (P > 0.05). The proportion of steers in each USDA Quality and Yield Grade category did not differ (P > 0.05) between treatments or years. Stocking rate and year interacted (P < 0.01) for HCW (kg per hectare) and carcass value per hectare. Hot carcass weight and value per hectare increased (P < 0.01) as stocking rate increased with the interaction caused by differences among years in whether moderate stocking differed (P < 0.05) from light or heavy stocking.

Conclusion: Differences in vegetative composition driven by stocking rate did not carry over to impact carcass traits. However, heavier stocked pastures returned greater overall beef production and economic value due to the increase in animals produced per unit of land. Findings from this research demonstrated that stocking rate can influence the profitability of an operation without negatively impacting carcass traits.

Keywords: stocking rate, production, carcass traits

21 INFLUENCE OF DIVERSE FINISHING SYSTEMS ON CARCASS AND TENDERNESS CHARACTERISTICS OF BISON HEIFERS

L. M. O’Sullivan^1,*, C. E. Bakker¹, K. R. Underwood¹, E. Huff-Lonergan², J. K. Grubbs¹, L. G. Johnson², S. M. Lonergan², G. T. Weldy¹, C. Kruse³, A. D. Blair¹, ¹Animal Science, South Dakota State University, Brookings, South Dakota, United States, ²Animal Science, Iowa State University, Ames, Iowa, United States, ³Turner, Institute of Ecoagriculture, Bozeman, Montana, United States *lydia.osullivan@sdstate.edu

Objectives: The objectives of this study were to compare the influence of diverse finishing systems on 1) carcass characteristics of bison heifers, and 2) calpastatin activity and tenderness of striploin steaks from bison heifers.

Materials and Methods: At ∼24 mo of age, single sourced bison heifers (n = 276) were randomly assigned to one of 6 finishing systems (n = 46/treatment): 1. Range-finished on a diverse range (R-D), 2. Range-finished with limited forage diversity (R-LF), 3. R-LF with free choice supplementation of corn (R-LFC), 4. Pen-finished with a free choice diet (grass hay, alfalfa, corn) and low stocking density (P-FCL), 5. Pen-finished with P-FCL ingredients in a total mixed ration and low stocking density (P-TRL), or 6. P-TRL with high stocking density (P-TRH). Heifers were slaughtered at ∼30 mo of age. Following carcass chilling, hot carcass weight (HCW), 12^th rib backfat, ribeye area (REA), marbling score, and lean and external fat color (L*, a*, b*) were recorded. One strip loin was removed from a subsample of carcasses (n = 180; 30 closest to the average HCW/treatment) and fabricated into 2.54-cm steaks. One steak from each strip loin was vacuum packaged and stored fresh for 14 d at 4°C for Warner-Bratzler shear force (WBSF) evaluation. Steaks designated for WBSF were weighed before and after cooking to calculate cook loss percentage. One steak from R-D and P-FCL striploins (n = 20/treatment) was aged for 4 d, and heated sarcoplasmic protein extracts from each sample were used to measure calpastatin activity against porcine lung m-calpain. Data were analyzed for the fixed effect of finishing treatment in the MIXED procedure of SAS.

Results: Overall, pen-finished heifers (P-FCL, P-TRL, and P-TRH) had increased (P < 0.05) HCW and marbling scores compared to range-finished heifers (R-D, R-LF, and R-LFC). Backfat thickness of pen-finished heifers was greater (P < 0.05) than R-D and R-LF carcasses, while R-LFC were intermediate and similar (P > 0.05) to all other treatments. The R-D treatment generated the smallest (P < 0.05) REA compared to all other treatments, while pen-finished heifers with low stocking density (P-FCL and P-TRL) had greater (P < 0.05) REA compared to range-finished heifers, with P-TRH intermediate and similar (P > 0.05). The L* and b* of backfat opposite the ribeye from R-D and R-LF heifers was greater (P < 0.05) than all other treatments. Heifers in the R-D treatment had the lowest L* value of the lean surface of the ribeye, while R-D and R-LF had the lowest (P > 0.05) a* values. Finishing treatment did not influence (P > 0.05) WBSF; however steaks from all treatments had a WBSF < 3.0 kg. Steaks from heifers in the R-D and R-LF treatments had a greater (P < 0.05) percentage of cook loss compared to steaks from R-LFC, P-FCL, and P-TRH heifers with P-TRL intermediate and similar (P > 0.05) to all other treatments. Steaks from heifers in the P-FCL treatment had greater (P < 0.05) calpastatin activity compared to R-D.

Conclusion: Pen-finishing generally produced heavier carcasses with increased marbling and backfat. Steaks from pen-finished heifers with access to a free choice diet had greater calpastatin activity than heifers finished on diverse range indicating more inhibition of calpain earlier postmortem. However, this difference did not translate to differences in WBSF, indicating acceptable bison tenderness can be produced with diverse finishing systems.

Funding Source: Turner Institute of EcoAgriculture (grant 3PA166) and the South Dakota State Experiment Station

Keywords: bison, calpastatin activity, diet diversity, finishing system, tenderness

22 FINISHING DIET INFLUENCES COLOR STABILITY OF BISON STRIP LOIN STEAKS

G. T. Weldy^1,*, C. E. Bakker¹, J. K. Grubbs¹, K. R. Underwood¹, L. M. O’Sullivan¹, S. P. Suman², C. Kruse³, A. D. Blair¹, ¹Animal Science, South Dakota State University, Brookings, South Dakota, United States, ²Animal and Food Sciences, University of Kentucky, Lexington, Kentucky, United States, ³Turner, Institute of Ecoagriculture, Bozeman, Montana, United States *19gweldy@gmail.com

Objectives: Both grain- and grass-finishing systems are common in bison production; however, it is unclear how these systems impact meat color during retail display. Therefore, the objective was to determine the influence of finishing systems on color stability of bison strip loin steaks.

Materials and Methods: Bison heifers (24 mo of age) were randomly assigned to 4 finishing treatments (n = 30 per treatment): 1) grass-finished on diverse range (DR), 2) grass-finished with limited diversity (LD), 3) grain-finished with ad libitum access to prairie hay, alfalfa hay, and corn (AL), and 4) grain-finished with access to a total mixed ration (TMR) with ingredients from AL. Heifers were slaughtered at 30 mo of age. Strip loins were collected from a subsample (n = 15 carcasses closest to the treatment average a*) and fabricated into 2.5-cm steaks for a simulated retail display using 2 packaging types. One steak was designated for overwrap (OW) packaging and one was vacuum packaged (VAC). Steaks assigned to OW were placed under a simulated retail display at 1.7°C ± 2.8°C and evaluated for 10 d. Steaks assigned to VAC were placed in dark storage for 10 d, then placed under simulated retail display and evaluated for 29 d. Daily objective color measurements (L*, a*, b*) were recorded during the display period using a colorimeter, and hue angle was calculated as a measure of discoloration. Color measurements were analyzed as a repeated measure with display day, finishing treatment, and their interaction as fixed effects using the MIXED procedure of SAS.

Results: Diet × display day interactions (P < 0.0001) were observed for all color measurements across both packaging types. The a* values of OW steaks from the grass-finished treatments did not differ from day 7 through 10 (P > 0.05), while the grain-finished samples decreased in redness and were less red than the grass-finished (P < 0.05). All OW steaks decreased (P < 0.05) in a* from day 0 to 10. The VAC steaks from grain-finished treatments were redder (P < 0.05) than the grass-finished on day 10; however, by day 29, the grass-finished treatments were redder (P < 0.05) than the grain-finished. The a* value of VAC steaks from the grain-finished treatments decreased (P < 0.05) over the 29-d display period, while the grass-finished steaks did not differ (P > 0.05) from day 0. By day 10, the hue angle of the OW DR samples was less (P < 0.05) than all other treatments indicating less discoloration. All OW steaks increased (P < 0.05) in hue angle from day 0 to 10. The hue angle of the VAC LD samples did not differ (P > 0.05) between day 0 and 29, while the hue angle of all other treatments increased (P < 0.05). The L* of OW steaks from all treatments increased (P < 0.05) from day 0 to 10. When steaks were subjected to VAC, the LD treatment had a lower L* value (P < 0.05), while the L* of grain-finished treatments increased (P < 0.05) from day 0 to 29. The b* value of OW steaks from all treatments decreased (P < 0.05) from day 0 to 10. When subjected to VAC, the b* of steaks from LD and AL treatments did not differ (P > 0.05); however, the b* of VAC steaks from the DR and TMR treatments increased (P > 0.05) from day 0 to 29.

Conclusion: Data indicate that grass-finished bison steaks maintain color longer than grain-finished regardless of packaging. These findings can inform management and packaging strategies aimed at improving the stability of bison color during retail display.

Funding Source: The South Dakota State University Experimental Research Station

Keywords: bison, color stability, discoloration, finishing systems, packaging

23 THE IMPACT OF WILDFIRE ON BEEF QUALITY, AND AMELIORATION STRATEGIES: A REVIEW

M. Hastie^1,*, S. S. Chauhan¹, C. Pfeiffer², R. D. Warner¹, ¹School of Agriculture, Food and Ecosystem Sciences, ²Veterinary Biosciences, The University of Melbourne, Melbourne, Australia *mhastieunimelb.edu.au

Objectives: This review aims to consolidate the current state of knowledge regarding the impact of wildfire on beef quality to inform the development of mitigation strategies.

Materials and Methods: This review focuses on identifying the probable/potential impacts of wildfire on the beef quality attributes of loin pH and color of loin at time of grading. It also proposes mitigation or remediation practices to address these quality issues. Literature focusing on the effects of heat and fire exposure and smoke inhalation on livestock was reviewed, with articles sourced from veterinary, animal, and meat science journals. Upon identification of the influence of these factors on animal physiology and the resulting impacts on beef quality, the same journals were reviewed for amelioration strategies and interventions that would mitigate the effects of wildfire exposure.

Results: Figure 1 summarizes the direct and indirect impacts of wildfire on beef quality. Contact with fire can cause direct physiological stress through heat stress, oxidative stress, and glycogen depletion (Celi, 2011; de Carvalho et al., 2016), as well as physical injury through smoke inhalation or burns (Rogers et al., 2015). In addition, fire destroys pasture and feed and it can disrupt access to water and induce heat stress. Some animals and production systems are more susceptible to fire impacts with grass fed animals more affected than grain fed, and HGP (hormone growth promotant) treated animals more affected than non-HGP treated (Hastie et al., 2022, 2023). Emergency fire response activities can exacerbate animal stress; e.g., fencing may be lost and roads closed due to fire, leading to more stressed cattle upon loading and longer transportation times. Animals may need to be processed quickly, and lairage times and conditions may not allow animal recovery from transportation stress. Beef carcases can be rejected or downgraded at the processor due to high pH or dark color at grading; both quality defects are associated with wildfire exposure and muscle glycogen depletion. For glycogen depleted animals, glycogen may return to basal levels within a week provided further stress is avoided and access to feed and water is provided. However, if animals have had a protracted period with a low metabolizable energy intake, such as occurs with pasture and/or roughage-based diets, feeding a high energy diet for 2 to 3 wk before processing may be required to reduce the incidence of high pH and dark-cutting (Immonen et al., 2000; Knee et al., 2007; McGilchrist et al., 2012). Return to basal glycogen levels can be faster if supplementary energy is provided through water enhancement using glycerol or propylene glycol (Pethick et al.,1999). In terms of ameliorating heat stress and oxidative stress, reducing exposure to heat, correction of acid base balance (reducing oxidative stress), and improving heat tolerance of animals can improve outcomes through (i) physical modification of animal’s environment, (ii) nutritional strategies to reduce metabolic heat production or mitigate the negative effects of heat stress (e.g., anti-oxidant supplementation), and (iii) genetic selection for heat tolerance (Osei-Amponsah et al., 2019). On fire-affected farms in the short term, provision of shade, shelter, and nutritional interventions are the most relevant.

Figure 1.

The impacts of wildfire on loin colour and pH at grading; the direct impacts of wildfire exposure on cattle and the indirect effects of wildfire related to production systems and supply chain

Conclusion: Wildfire exposure is associated with unfavorable beef quality outcomes. As wildfires become increasingly prevalent with global climate change, further research coupled with economic modeling would assist producers with selection of amelioration strategies, especially where supplemental feeding may be required for fire-affected animals.

Funding Source: Meat and Livestock Australia are gratefully acknowledged for funding this project.

Keywords: beef, meat quality, sheep, wildfire

24 THE COMPARATIVE EFFECTS OF ESSENTIAL OIL AND MONENSIN SUPPLEMENTATION ON THE FECAL RESISTOME IN HOLSTEIN STEERS

S. Talukder^1,*, Y. Feng¹, P. H. V. Carvalho^1,2, B. C. Latack³, R. A. Zinn¹, X. Yang¹, ¹Department of Animal Science, University of California, Davis, Davis, California, United States, ²AgNext–Department of Animal Science, Colorado State University, Fort Collins, Colorado, United States, ³Cooperative Extension, Division of Agriculture and Natural Resources, University of California, Holtville, California, United States *stalukder@ucdavis.edu

Objectives: The practice of administering ionophores to cattle for growth promotion has come under scrutiny due to concerns regarding their potential to facilitate the emergence and dissemination of antimicrobial resistance. Therefore, to address the issue, it has become imperative to assess the influence of potential alternatives on the fecal resistome of cattle. The objective of this study was to evaluate the effects of a supplemental blend of essential oils and 25-hydroxyvitamin D3 (EO+HYD) on the fecal resistome of Holstein steers.

Materials and Methods: Seventy-five Holstein steer calves (123 ± 7 kg; 4 mo old) were randomly assigned to 15 pens (5 steers/pen; 5 pens/treatment). Dietary treatments consisted of a steam-flaked corn-based diet supplemented with (DM basis): (1) no additives; (2) 30 mg/kg DM of monensin; (3) 200 mg/kg DM of a mixture of EO+HYD. Pen floor fecal samples were collected at 6 distinct time points, specifically on days 0, 36, 96, 156, 216, and 278. Total microbial DNA was extracted from the fecal samples using the DNeasy PowerSoil Pro Kit, following the manufacturer’s protocol, shotgun sequencing was performed using Illumina NovaSeq 6000 platform followed by library preparation using Illumina TruSeq library kit, and the subsequent resistome analysis was conducted. Alpha and beta diversities were assessed using Chao1 and Shannon indices and Non-Metric Multidimensional Scaling (NMDS) using Bray-Curtis dissimilarity, respectively. ANOVA was used to compare the relative abundances of antimicrobial resistance genes (ARG) among treatment groups. All statistical analyses were conducted in R (v4.1.2) with an alpha level set as 0.05.

Results: The findings of the study revealed that while alpha diversity of fecal ARG did not differ among treatment groups, variations (P < 0.05) were observed over time, indicating a decrease in ARG richness as cattle age, irrespective of supplementation. Beta diversity analysis showed no significant differences (R² = 0.028, P = 0.249) in resistome profiles of ARG among treatment groups, suggesting minimal influence of either monensin or EO+HYD supplementation. Similarly, no distinctions were found in the composition of fecal antimicrobial resistance at the mechanism level (R² = 0.03, P = 0.244), or drug level (R² = 0.026, P = 0.308) among treatment groups across different sampling times. The most abundant genes associated with the antimicrobial resistance mechanisms found in all the samples are Macrolide-resistant 23S rRNA mutation (35.89%), Aminoglycoside-resistant 16S ribosomal subunit protein (23.06%), and Oxazolidinone-resistant 23S rRNA mutation (14.5%). The steers in the EO+HYD and monensin-supplemented groups had a lower (P < 0.05) abundance of resistance genes associated with Macrolide-resistant 23S rRNA mutation and Aminoglycoside-resistant 16S ribosomal subunit protein compared to the steers from control groups. In addition, ARG are most commonly associated with resistance to Macrolide-Lincosamide-Streptogramin (MLS) (38.06%), Aminoglycosides (23.76%), Oxazolidinone (14.5%), and Tetracyclines (13.37%). Steers from the EO+HYD and monensin group were found to have a lower (P < 0.05) abundance of MLS resistance genes in their feces than the steers from the control group.

Conclusion: The present study indicates that there was no substantial change observed in the fecal resistome of the steers supplemented with either antibiotics or EO+HYD. It underscores the need for further research on phenotypic expression coupled with genotypic potential which may provide insights into the dynamic regulation of specific AMR genes, including potential downregulation mechanisms.

Funding Source: This project was supported through the California Department of Food and Agricultulture.

Keywords: diversity, essential oil, Holstein steers, monensin, resistome

25 A PRELIMINARY STUDY TO DETERMINE THE IMPACT OF FEEDLOT AMBIENT TEMPERATURE EFFECT ON DARK-CUTTING SEVERITY

B. Robbins^1,*, M. A. Scott¹, K. Harr¹, G. G. Mafi¹, R. Ramanathan¹, J. A. Scott¹, M. M. Pfeiffer¹, ¹Department of Animal and Food Sciences, Oklahoma State University, Stillwater, Oklahoma, United States *madelyn.scott@okstate.edu

Objectives: Dark-cutting (DC) beef is a condition that can be caused by long-term stress prior to slaughter resulting in discounted carcasses and decreased consumer acceptance. Research has shown that heat and cold stress can predispose cattle to DC conditions. However, limited studies have examined the effects of feedlot temperature on severity of DC conditions. Therefore, the study objective was to evaluate the impact of ambient feedlot temperature on DC severity in beef.

Materials and Methods: The data for this study were derived from 5 feedlots in the Midwestern U.S. Two to nine cattle were selected from each feedlot and harvested on April 5^th and 6^th, 2023. At the time of harvest, 2 carcasses were over 30 mo and 19 were under. Ten of the cattle were steers and 11 were heifers. Fourteen of the cattle were identified as black Angus; 7 were from other breeds not identified. All cattle were finished on grain. Carcasses were selected based on the visual severity of darkening in the ribeye (n = 21). A USDA grader assisted in segregating DC carcasses from those exhibiting a normal bright cherry-red (BCR) color in the ribeye (Longissimus dorsi), following the parameters outlined by our laboratory. Carcasses were allocated to treatments as follows: one-half, two-thirds, and full DC, and a normal BCR colored control. Based on geographical location data provided by AccuWeather, the average temperature during the 90 d prior to harvest for these cattle was calculated utilizing the high and low averages every 30 d. Temperature and severity of DC were compared using the GLIMMIX procedure of SAS to determine differences in average temperature impact on severity of DC with α set at 0.05.

Results: The average high temperatures over 90 d for all feedlots for normal BCR colored control, one-half, two-thirds, and full DC were 10.88, 10.99, 10.25, and 10.55°C, respectively, while the average low temperatures were −6.38, −5.7, −6.36, and −6.2°C. The average high temperatures for the 3 d prior to harvest for normal BCR colored control, one-half, two-thirds, and full DC were 15.09, 16.78, 14.39, and 15.07°C, respectively, while the average low temperatures were 1.73, 0.55, −0.39, and 2.45°C. The average 12^th rib fat thickness for normal BCR colored control, one-half, two-thirds, and full DC were 1.22, 1.57, 1.47, and 1.57 cm, respectively, while the average ribeye areas were 97, 95, 95, and 93 cm². The average hot carcass weights for normal BCR colored control, one-half, two-thirds, and full DC were 381, 376, 390, and 383 kg, respectively. The average marbling scores for normal BCR colored control, one-half, two-thirds, and full DC were Sm⁰⁹, Mt³⁰, Mt⁴⁶, and Mt⁴⁰, respectively.

Conclusion: The results of this study indicate no significant temperature effect for DC severity in the ribeye (P > 0.05). Carcasses were selected from feedlots in near proximity to each other resulting in minimal change in weather patterns and similar changes in conditions. Further research utilizing more severe temperatures and greater differences, as well as a larger carcass sample set, would be beneficial to determine weather impacts on severity of DC.

Keywords: beef, dark-cutting, feedlot, temperature

26 EFFECTS OF BACTERIAL DIRECT-FED MICROBIAL SUPPLEMENTATION ON IN VITRO TRUE DIGESTIBILITY, FERMENTATION KINETICS, AND GREENHOUSE GAS PRODUCTION IN BEEF CATTLE ON A HIGH CONCENTRATE RATION

T. B. Mckinzie^1,*, B. Q. Reis¹, J. O. Sarturi¹, D. R. Woerner¹, ¹Animal and Food Sciences, Texas Tech University, Lubbock, Texas, United States *taylor.schertz@ttu.edu

Objectives: Direct-fed microbials (DFM) have been investigated for gas emission reduction and improved digestibility of nutrients in beef cattle in an effort by every sector of the beef industry to develop new strategies to meet the demand of sustainable red meat production. Thus, more DFM have come to market. Therefore, the objective of the study was to evaluate in vitro true digestibility of nutrients, fermentation, and the gas production profile of a beef cattle finishing diet inoculated with a novel Bacilli DFM.

Materials and Methods: Rumen fluid collected from 2 ruminally cannulated steers adapted to a beef cattle finishing diet was used to perform 7 in vitro batches in a complete, randomized block design (block = incubation batch). An animal-equivalent dose of the DFM solution (Bacillus licheniformis, 4.54 × 10¹⁰ CFU/lb; Bacillus subtilis, 4.54 × 10¹⁰ CFU/lb) was proportionally scaled to the in vitro unit volume (ruminal inoculum [50 mL] + buffer [150 mL] =200 mL), assuming an average ruminal volume of 70 L. The recommended dose of the DFM is 2 mL/hd/d; therefore, treated in vitro flasks (250 mL) received 5.71 μL of the DFM. Each batch of 10 flasks included triplicates of control (CON) and treatment (TRT), and duplicates of a blank chamber and known internal standard. The CON and TRT flasks were inoculated with 0.005 kg of a high-concentrate diet substrate, the known internal standard had 0.005 kg of a low-quality forage substrate, and the blank chambers did not have feed. Flasks (250 mL) were coupled to ANKOM gas collection systems and set to take continuous gas measurements for 24 h. The in vitro true digestibility of dry matter, organic matter, and fiber components (neutral detergent fiber [NDF] and acid detergent fiber [ADF]) were measured from in vitro residues after the 24 h incubation. Gas was analyzed for total gas production, methane (CH₄), and CO₂, using gas chromatography. Ruminal fluid pH and ammonia-N measurements were recorded after the 24 h incubation period. Data were analyzed using PROC GLIMMIX of SAS, where treatment served as a fixed effect.

Results: NDF digestibility was different between treatments (P < 0.05), where TRT had the highest percent NDF digestibility(P < 0.05). When analyzing NDF alone, TRT resulted in a 15% improvement in fiber digestibility and a 2% improvement in energy efficiency. In vitro true dry matter and organic matter digestibility, as well as ADF digestibility, were not different between CON and TRT (P > 0.05); however, TRT values were numerically higher. No differences were observed for ammonia, pH, and gas production factors between treatment groups (P > 0.05). Across batches, TRT was numerically higher for total gas volume, with similar CH₄ and less CO₂ levels; however, the higher total gas volume could be attributed to greater nutrientdigestibility of the DFM in TRT.

Conclusion: The use of a Bacilli DFM in a beef cattle finishing diet can improve nutrient digestibility, resulting in greater energy efficiency. Further calculations should be assessed to understand the CH₄ and CO₂ levels produced relative to an increase in dry matter intake. Additionally, a live-animal study would be beneficial to analyze the effects of the DFM on animal health and performance in a feedlot setting, as well as its translation to red meat yield and quality.

Funding Source: South Plains Compost

Keywords: cattle, direct-fed microbials, digestibility, in vitro, nutrient

27 FATTY ACID COMPOSITION OF “GRASS-FED” AND “GRAIN-FED” BEEF RAISED IN SOUTHEAST ARIZONA

L. D. L. C. Garcia^1,*, A. C. Skulas-Ray², S. R. Garcia¹, D. M. Wulf¹, ¹Animal and Comparative Biomedical Sciences, ²Nutritional Sciences and Wellness, The University of Arizona, Tucson, Arizona, United States *lucilagarcia@arizona.edu

Objectives: Previous studies have shown that beef from cattle fed a grass-based diet has a different fatty acid composition than beef from cattle fed a grain-based diet. This study compared the fatty acid composition of “grass-fed” beef to “grain-fed” beef from cattle raised in the Madrean Archipelago Ecoregion of southeast Arizona.

Materials and Methods: Longissimus muscle (MUS) and subcutaneous adipose tissue (FAT) were sampled from 27 beef carcasses originating from 7 southeast Arizona livestock producers. Based on producer claims, carcasses were classified as either grain-fed (n = 15) or grass fed (n = 12). Data were analyzed separately for MUS and FAT as well as for 80/20 and 90/10 ground beef; fatty acid quantities in ground beef were determined for each animal by creating ground beef blends mathematically based on total fatty acid amount of individual MUS and FAT samples. Statistical significance was determined using a mixed model, with treatment as a fixed effect and producer nested within treatment as a random effect; animal was the experimental unit.

Results: Grass-fed carcasses had lighter hot carcass weights (244 vs. 368 kg), less fat thickness (4.2 vs. 17.7 mm), smaller ribeye areas (61.5 vs. 85.3 sq cm), less kidney/pelvic/heart fat (1.4% vs. 3.0%), lower USDA yield grades (2.09 vs. 3.69), and lower marbling scores (Slight 80 vs. Modest 02) than grain-fed carcasses (P < 0.05). Grass-fed MUS has lower amounts of C18:0, C18:1-cis, C22:4, and total fatty acids and greater amounts of C18:3(n3), C20:5, C22:5(n3), C22:6, and C24:1 than grain-fed MUS (P < 0.05). Grass-fed FAT had lower amounts of C:18:1-cis, C18:2-cis, C20:1, C22:4, total monounsaturated fatty acids, and total fatty acids and greater amounts of C16:1-trans, C18:2-trans, C18:3(n3), C20:0, C20:5, C22:0, C24:0, and total saturated fat than grain-fed FAT (P < 0.05). Grass-fed 80/20 ground beef had lower amounts of C18:1-cis, C18:2-cis, C20:1, C20:4, C22:4, C22:5(n6), and total monounsaturated fatty acids and greater amounts of C16:1-trans, C18:0, 18:2-trans, C18:3(n3), C18:3(n6), C20:0, C20:5, C22:0, C22:5(n6), C22:6, C24:0, C24:1, and total saturated fats than grain-fed 80/20 ground beef (P < 0.05). Grass-fed 90/10 ground beef had lower amounts of C18:1-cis, C18:2-cis, C20:1, C22:4, and greater amounts of C16:1-trans, C18:2-trans, C18:3(n3), C18:3(n6), C20:0, C20:5, C22:0, C22:5(n3), C22:6, C24:0, C24:1, and total saturated fats than grain-fed 90/10 ground beef (P < 0.05). In all products, grass-fed beef had a greater amount of total n-3 fatty acids (1.10 vs. 0.44 mg/g for 90/10 ground beef) and a lower n-6:n-3 ratio (3.0:1 vs. 8.6:1 for 90/10 ground beef) (P < 0.05). In both ground beef products, grass-fed beef had a greater amount of total trans fatty acids (4.69 vs. 2.94 mg/g in 90/10 ground beef) (P < 0.05).

Conclusion: Grass-fed cattle from the Madrean Archipelago Ecoregion of southeast Arizona produced lighter weight and leaner carcasses, beef products with more n-3 fatty acids and lower n-6:n-3 ratios, and ground beef products with more saturated fat and trans fatty acids than grain-fed cattle. Marketing claims regarding greater n-3 fatty acids in grass-fed beef are valid; nevertheless, due to higher saturated and trans fatty acid proportions, human health implications of consuming grass-fed versus grain-fed beef should be further investigated.

Keywords: Arizona, fatty acid, grain-fed, grass-fed, Madrean Archipelago Ecoregion

28 A COMPARATIVE ANALYSIS OF ESSENTIAL OIL AND MONENSIN SUPPLEMENTATION EFFECTS ON THE FECAL MICROBIOME IN HOLSTEIN STEERS

M. S. Islam^1,*, S. Talukder¹, Y. Feng¹, B. C Latack², R. A Zinn¹, P. H V Carvalho^1,3, X. Yang¹, ¹Department of Animal Science, University of California, Davis, Davis, California, United States, ²Cooperative Extension, Division of Agriculture and Natural Resources, University of California, Holtville, California, United States, ³AgNext–Department of Animal Science, Colorado State University, Fort Collins, Colorado, United States *mspislam@ucdavis.edu

Objectives: The composition and diversity of the fecal microbiome play a critical role in livestock health and performance. The ban on growth-promoting antibiotics in animal feeds in different nations has resulted in a heightened focus on alternative approaches to enhance animal productivity. This study was conducted to assess the effects of a combination of supplemental essential oil (EO) and 25-hydroxyvitamin-D3 (HYD) to monensin (MON) on the fecal microbiome in Holstein steers receiving a standard growing-finishing diet.

Materials and Methods: Ninety Holstein steer calves (average weight: 123 ± 7 kg; aged 4 mo) were randomly assigned to 3 dietary treatment groups (6 steers/pen, 5 pens/treatment). The dietary treatments included a steam-flaked corn-based diet with the following supplements (on a dry matter basis): (1) no additives (CON); (2) 30 mg/kg of dry matter (MON); (3) 200 mg/kg of dry matter of a blend of EO+HYD. Fecal samples were collected from each pen floor on separate days (D0, D36, D96, D156, D216, and D278) and subjected to shotgun metagenomic sequencing. Microbiome analysis was conducted to calculate the alpha diversity of the microbial species (Shannon and Chao1 indices), while beta diversity was determined by the non-metric multidimensional scaling plot. Two-way ANOVA was performed to determine the difference among abundant taxa. All the analyses were performed in the R program (version 4.3.2) with a significance level set at α = 0.05.

Results: Alpha diversity analysis revealed fecal microbial richness changed (P < 0.05) over time. However, the alpha diversity index was not different (P > 0.05) among the treatment groups. In addition, the fecal microbial composition of the cattle remained the same (P > 0.05) among the treatment groups on early sampling days but was different (P < 0.05) at the end of the production (on day 278). The phylum Firmicutes (69.9%) was the most abundant (P < 0.05) detected in fecal samples, followed by Actinobacteria (16.8%), Euryarchaeota (5.9%), Bacteroidetes (4.3%), and others. Moreover, the most abundant genera were Clostridium (10.5%), Turicibacter (9.1%), Sarcina (8.4%), Bifidobacterium (6.9%), Methanobrevibacter (5.1%), Corynebacterium (4.2%), and others. The abundance of Bifidobacterium was lower (P < 0.05) in the MON groups compared to the CON group, indicating that MON inhibits the growth of Bifidobacterium, which is a Gram-positive bacterium. Moreover, Bifidobacterium and Corynebacterium were also more abundant (P < 0.05) in the CON than in the EO group, suggesting that EO may have inhibitory effects on these bacteria, as their growth is comparatively lower in the EO group.

Conclusion: While the overall fecal microbiome of cattle fed different dietary treatments did not exhibit distinct differences in the present study, the abundances of specific bacterial genera were influenced by the combination of supplemental EO and HYD or MON. Further investigations are necessary to evaluate the impact of antibiotic alternatives on the microbiome across different segments of the digestive tract of cattle, as microbiome composition varies within these segments.

Funding Source: This research project was funded by California Department of Food and Agriculture.

Keywords: cattle, essential oil, fecal microbiota, microbial population, monensin

29 EFFECT OF XANTHAN-LOCUST BEAN GUM MIXTURES ON THE PHYSICOCHEMICAL, TEXTURE, AND SENSORY PROPERTIES OF LOW-FAT SAUSAGE

S. Massey^1,*, R. Flinchum¹, H. Khouryieh², L. Silva¹, ¹Department of Agriculture & Food Science, ²Food Processing & Technology, School of Engineering & Applied Sciences, WKU, Bowling Green, Kentucky, United States *samantha.massey289@topper.wku.edu

Objectives: Sausages enjoy widespread popularity throughout the United States, yet they are known for their elevated fat content. High fat consumption has been linked to various health issues such as cardiovascular diseases, obesity, cancer, and hypertension. As a result, health-conscious consumers are actively seeking healthier and more functional foods. This study aimed to explore how substituting some of the fat with different combinations of xanthan gum and locust bean gum (XLB) would impact the physicochemical and sensory properties of low-fat sausages.

Materials and Methods: To prepare sausage formulations, beef lean trimmings and beef fat trimmings were acquired from Western Kentucky University (WKU) Meat Science Lab. After grinding, the meat trimmings were stored at −20°C until emulsion preparation. Other ingredients used in the sausage formulations included spices blend, sodium chloride, curing salt, sodium phosphate, sodium erythorbate, xanthan gum, and locust bean gum. Six sausage formulations were prepared to evaluate the effect xanthan and locust bean gum mixture (XLB) inclusion level on the sausage quality: high fat control (HF, 20% fat), low fat control (LF, 10% fat), and LF with 4 levels of XLB mixture (LF+0.5%XLB, LF+1%XLB, LF+1.5%XLB, and LF+2%XLB). The formulations were replicated for 3 d. The sausages were evaluated for quality parameters like proximate analysis, pH, emulsion stability, water activity, color, texture profile analysis (TPA), and sensory attributes. The TPA and color were evaluated on both day 1 and 28. The sensory evaluation was conducted with 6 trained panelists, who scored the flavor and texture attributes of hardness, cohesiveness, juiciness, and flavor using an 8-point scale. The data were analyzed by SAS software using PROC MIXED procedure, and the means were compared using Tukey’s test at 5% significance level.

Results: The results showed that moisture content was lower for HF than all other treatments (P < 0.05), but it did not differ among the treatments with XLB (P > 0.05). Protein content was significantly higher in HF than all other treatments (P < 0.05). There was no significant difference (P > 0.05) among treatments for water activity. There was also no significant difference in pH (P > 0.05). The L* and a* color values were not significantly (P > 0.05) affected among treatments or days, while b* values on day 28 were significantly (P < 0.05) lower in HF, LF, LF+0.5%XLB, and LF+1%XLB compared to LF+1.5%XLB and LF+2%XLB. The TPA results revealed hardness on day 1 was higher (P < 0.05) in HF than LF+0.5%XLB, LF+1%XLB, LF+1.5%XLB, and LF+2%XLB. No significant differences in hardness were observed on day 28 among all treatments. Sensory analysis revealed that no significant (P > 0.05) differences were observed in flavor intensity between HF, LF, LF+0.5%XLB, and LF+1%XLB. Juiciness did not exhibit any significant (P > 0.05) differences among all treatments.

Conclusion: Adding up to 1% XLB led to satisfactory sensory results for the sausage formulation, suggesting its promise as a fat substitute in low-fat sausages. Substituting part of the fat with a XLB gum mixture in meat emulsions has the potential to create healthier restructured meat products that contain less fat.

Funding Source: USDA, WKU FUSE grant

Keywords: locust bean gum, low fat, physicochemical properties, sausage, xanthan gum

30 QUALITY AND SENSORY ATTRIBUTES OF TUMBLED OR MARINATED BEEF JERKY

A. L. McGinn^1,*, D. L. Boyle², T. G. O’Quinn¹, E. A. E. Boyle¹, ¹Animal Science, ²Biology, Kansas State University, Manhattan, Kansas, United States *ashton.mcginn5@gmail.com

Objectives: This research evaluated quality and sensory characteristics of vacuum-packaged shelf-stable beef jerky produced using tumbling or marination.

Materials and Methods: Twelve USDA select beef inside top rounds (semimembranosus) were held at 2°C for 10 to 14 d before processing. Each of the 12 rounds was trimmed and weighed, and pH was measured before being manually cut in half. Once halved they were divided into 2 treatments of tumble or marinade before being sliced using a slicer into 3 mm slices. These raw samples were later analyzed for moisture, fat, and protein. Transmission electron microscopy (TEM) and light microscopy (LM) were used to assess structural changes, sarcomere length (SL), and myofiber diameter (MD). After tumbling or marination, percent pick up, sodium chloride content (SCC), structural changes, SL, and MD were determined. After thermal processing, percent cook yield, water activity (a_w), pH, moisture and protein content, color, shear force (SF), sensory, SCC, SL, and MD were measured. Vacuum-packaged jerky was stored at 20°C and evaluated after 3 and 6 mo of storage for color, sensory, a_w, SF, SCC, moisture, structural changes, SL, and MD.

Results: Data were analyzed using a 3 × 2 factorial design where fixed effects were tumbling and marinating of raw, raw tumbled, and raw marinated samples stored at day 0, 3, and 6 mo with individual rounds as a random blocking factor. The SL and MD results were analyzed separately based on the main effects of the treatment method. There was no difference (P > 0.05) in pH, moisture, fat, or protein content among raw top round samples, as well as no difference (P > 0.05) in SL and MD. After tumbling and marination, there was no difference (P > 0.05) in the SCC, SL, or MD samples. The percent pick-up was higher (P < 0.05) in tumbled than marinated slices. After thermal processing (day 0), there was no difference (P > 0.05) between treatments for percent cook yield, pH, a_w, SF, protein or SCC, SL, and MD. The moisture content was higher (P < 0.05) in jerky produced using tumbling. Jerky produced using tumbling had lower L* and higher a* values than marinated beef jerky. Regardless of the processing method, after 6 mo of storage beef jerky was darker (P < 0.05) and became more red (P < 0.05) compared to jerky at day 0 and 3 mo of storage. Shear force values were lower (P < 0.05) in tumbled versus marinated beef jerky. The trained panelists found that tumbled jerky was more tender, less brittle, and more flavorful than marinated jerky (P < 0.05). Tenderness and flavor declined (P < 0.05) at 3 mo of storage, and texture became more brittle (P < 0.05) at 6 mo of storage. This is similar to the LM and TEM data which showed visual differences and decreased structural integrity in raw top rounds, raw marinated or tumbled slices, and jerky from day 0 to 6 mo of storage. There was a decrease (P < 0.05) in SCC during storage and an interaction (P < 0.05) with the b* value that decreased for tumbling with process treatment and storage time but did not change for marination. All the other variables of a_w, SF, moisture, and MPR were similar (P > 0.05).

Conclusion: Tumbling produced a jerky product that was more tender, less brittle, and more flavorful during 6 mo of storage compared to marination as a processing method. Although tumbling yielded a higher percent pick-up and was darker in color than marination, the processing method did not influence the SCC, a_w, or MPR of jerky produced.

Keywords: beef jerky, marinade, microscopy, sensory, tumble

31 EVALUATING THE IMPACT OF DIFFERING SURFACE AREAS IN TRI-GAS MODIFIED ATMOSPHERE MASTER BAGS ON RETAIL DISPLAY OF BEEF STRIP LOIN STEAKS

G. E. Harris^1,*, M. Pfeiffer¹, R. Ramanathan¹, G. G. Mafi¹, ¹Animal and Food Sciences, Oklahoma State University, Stillwater, Oklahoma, United States *grace.harris@okstate.edu

Objectives: It is widely accepted that meat color is one of the greatest influences on consumer purchasing decisions, and divergence from the preferred bright cherry-red color negatively influences those decisions. Modified atmosphere packaging (MAP) has demonstrated color stability improvement of steaks during retail display. There are no standards on the weight of meat or surface area exposed within a master bag to achieve optimal retail display life. Thus, the objective of this study was to determine the effect of differing surface areas of beef strip loin steaks packaged in tri-gas MAP (CO-MAP) master bags on retail display.

Materials and Methods: Five USDA Choice strip loins were obtained at 14 d postmortem from a commercial processing plant and transported to Oklahoma State University for further processing. Strip loins were aged in vacuum packages at 2.0 ± 1°C for an additional 7 d. Following aging, strip loins were numbered 1–5 and cut to obtain four 3.8-cm steaks and eight 1.9-cm steaks. Steaks from loins 1–4 for both groups were randomly assigned to one of 8 master bags, which were preassigned to hold either 3.8-cm steaks for an average surface area of 350 cm² (normal surface area; NSF) or 1.9-cm steaks for an average of 700 cm² (doubled surface area; DSF). Therefore, 1 thick steak and 2 thin steaks from each of the 4 loins were placed into their respective master bags. Thick (3.8-cm) and thin (1.9-cm) steaks were alternately cut from the anterior end of each strip loin to have double the surface area in master bags of thin steaks while maintaining similar weight of all bags. Steaks from loin 5 were packaged and used for initial headspace analysis and oxygen depletion. Steaks were overwrapped in foam trays with polyvinyl chloride film and sealed in CO-MAP master bags (30% CO₂, 0.4% CO, 69.9% N₂) with an oxygen scavenger. Master bags were kept in dark storage at −1.0 ± 2°C for 15 d. Upon conclusion of the dark storage, headspace readings were collected on each bag before removing and placing steaks into a coffin-style retail display case under continuous LED lighting at 3.0 ± 2°C for 7 d retail display. Each day trained panelists evaluated steaks for lean color, surface discoloration, and overall acceptability. Instrumental color was measured each day in triplicate across the steak surface using a HunterLab MiniScan spectrophotometer. Data were analyzed using the GLIMMIX Procedure of SAS; differences were considered significant at P < 0.05.

Results: Residual oxygen increased over the initial 6 h in master bags for both thick and thin steaks. From h 6 to 24, NSF bag oxygen levels dropped while DSF bags stayed consistent for the remainder of the analysis period (48 h). Trained panelists scored (P < 0.05) NSF steaks brighter cherry-red colored for each day of display. All steaks had similar (P > 0.05) discoloration d 0–2 of retail display; however, NSF steaks had less (P < 0.05) discoloration than DSF steaks on d 3 through 6. Panelists reported that NSF steaks had greater (P < 0.05) acceptability on all but d 0 of retail display compared to DSF steaks. NSF steaks had higher (P < 0.05) a*, b*, and chroma values on each day of retail display.

Conclusion: Increased surface area of steaks packaged in CO-MAP master bags reduced retail display. Further research should be conducted to determine the optimal surface area, gas flush, and oxygen scavenger size used in CO-MAP packages to fully capitalize on the benefits.

Keywords: beef, packaging, retail color

32 EFFECT OF STORAGE TEMPERATURE AND DURATION ON COLOR AND ODOR DETERIORATION OF DIRECT ACIDIFIED PORK SAUSAGES FORMULATED WITH PRE-CONVERTED BEET AND CHERRY POWDER

S. Bentz^1,*, D. Setyabrata², J. R. Tuell¹, ¹School of Agricultural Sciences, Northwest Missouri State University, Maryville, Missouri, United States, ²Department of Animal Science, University of Arkansas, Fayetteville, Arkansas, United States *jtuell@nwmissouri.edu

Objectives: While the effects of storage duration on emulsion pork sausages formulated with alternative curing and reducing agents have been well documented, the influences of storage temperature and duration in direct acidified, semi-dry pork sausage have not been fully considered. This study evaluated the inclusion of pre-converted beet powder and cherry powder in direct acidified pork sausage stored at refrigeration and room temperatures in comparison to conventional sodium nitrite and sodium erythorbate.

Materials and Methods: Three independent batches were prepared consisting of 800 g of pork M. semimembranosus and M. biceps femoris and 200 g of pork backfat in each formulation. To each, 2.3% NaCl, 1.0% dextrose, 8.0% iced distilled water, and 1.0% encapsulated citric acid were included. Four formulations were prepared which included: (T1) sodium nitrite at 125 ppm ingoing nitrite, (T2) T1 + 547 ppm sodium erythorbate, (T3) pre-converted beet powder at 125 ppm ingoing nitrite (based on manufacturer recommendation), (T4) T3 + 1000 ppm cherry powder, and a control batch (CON) with no curing agent or accelerator. After thermal processing to 69°C, sausages were sectioned, vacuum packaged, and assigned to storage at 4°C (REF) or 21°C (ROOM) for 1, 7, 21, or 35 d. Cured color characterization, cured color fading, and off-odor were assessed by trained panelists (n = 8). Instrumental A₁₀ color attributes were measured in triplicate. The study was a complete block design. The fixed effects of formulation, storage temperature, storage duration, and interactions were analyzed using the PROC GLIMMIX procedure of SAS.

Results: T3 and T4 had lower CIE L* compared to T1 and T2, and all formulations were darker than CON (P < 0.05). Regardless of formulation and storage duration, REF maintained higher CIE a* than ROOM (P < 0.05). At 35 d of storage, samples including a cure accelerator (T2 and T4) maintained higher CIE a* and chroma values and lesser hue angle than T1 and T3 (P < 0.05). Sausages including beet (T3 and T4) were more yellow than sausages with sodium nitrite (T1 and T2; P < 0.05). Regarding the interaction of formulation and storage temperature, T4 in REF maintained greater R650/570 nm (cured color intensity) than T3 in ROOM (P < 0.05). Trained panelists observed cured color fading in T3 compared to T1 and T2 stored in REF at 21 d (P < 0.05). Additionally, within ROOM, fading was observed in T3 over T2 at 7 d and in T1 and T3 over T2 and T4 at 21 d (P < 0.05). The inclusion of a cure accelerator resulted in greater cured color characterization scores in T4 over T1 and T3, as well as in T2 over T1 (P < 0.05). Formulation did not influence off-odor development (P > 0.05), although off-odors were apparent by 21 and 35 d of storage (P < 0.05), especially apparent in ROOM.

Conclusion: Overall, pre-converted beet and cherry powders (T3 and T4) are effective at generating and maintaining cured color and delaying oxidation relative to conventional sodium nitrite and sodium erythorbate. The use of a cure accelerator (T2 and T4) is beneficial to cured color during storage shown by greater redness and saturation and lower hue angle relative to formulations without (T1 and T3). Pre-converted beet powder without cherry powder (T3) appears more prone to color deterioration when stored at ROOM or for an extended duration.

Funding Source: This work was funded by the Northwest Missouri State University Faculty Research Committee.

Keywords: alternative curing, cured meat color, oxidative stability, sensory analysis, storage conditions

33 ALTERNATIVE CURING AND REDUCING AGENTS IN DIRECT ACIDIFIED PORK SAUSAGES HELD OVERNIGHT OR IMMEDIATELY THERMALLY PROCESSED ON YIELD, TEXTURE, AND COLOR

H. Francis^1,*, S. Bentz¹, D. Setyabrata², J. R. Tuell¹, ¹School of Agricultural Sciences, Northwest Missouri State University, Maryville, Missouri, United States, ²Department of Animal Science, University of Arkansas, Fayetteville, Arkansas, United States *jtuell@nwmissouri.edu

Objectives: Consumer demand for alternative curing and reducing agents over conventional options has increased. Most literature evaluates the inclusion of these ingredients in emulsion sausages; however, use in pork sausages directly acidified with encapsulated citric acid has not been comprehensively assessed. This study evaluated the inclusion of pre-converted celery and beet powders, as well as cherry powder, in direct acidified pork sausages with or without overnight holding prior to thermal processing.

Materials and Methods: For each independent batch (n = 3), 2 pork legs were thawed for 72 h at 4°C, and M. biceps femoris and M. semimembranosus were excised. Muscles were ground through a 10 mm then 4.5 mm plate. A 3 × 3 × 2 factorial arrangement of treatments was prepared by adding curing salt #1 (NITRITE; 6.25% NaNO₂, 93.75% NaCl) or pre-converted celery (CELERY) or beet (BEET) powders targeted to 125 ppm of ingoing nitrite based on supplier recommendation. Additionally, sodium erythorbate (ERYTH) at 547 ppm, cherry (CHERRY) powder at 1000 ppm, or no cure accelerator (NONE) were included. All formulations included 2.3% NaCl, 1.0% dextrose, 1.0% encapsulated citric acid, and 8.0% distilled water. Sausages were stuffed into 3.81 cm diameter fibrous casings and held either overnight at 4°C for 16–18 h (OVERNIGHT) or not (IMMEDIATE) prior to thermally processing to 69°C in a commercial smokehouse. Measures of yield were taken at the completion of the thermal process, and texture profile analysis and A₁₀ instrumental color attributes were measured after 21 d of storage at 4°C under vacuum. Data were analyzed using PROC GLIMMIX of SAS 9.4 with a model analyzing the fixed effects of curing agent (NITRITE, CELERY, BEET), reducing agent (ERYTH, CHERRY, NONE), holding period (OVERNIGHT, IMMEDIATE), and their interactions.

Results: Curing and reducing agents did not impact yield; however, sausages from IMMEDIATE (83.6%) had improved yields over OVERNIGHT (81.8%; P < 0.05). Sausages from OVERNIGHT with CHERRY had slightly lower cohesiveness and chewiness than OVERNIGHT with ERYTH (P < 0.05). OVERNIGHT with CHERRY was less springy than IMMEDIATE with NONE (P < 0.05). Hardness was not significantly affected by any treatment combination. BEET was found to have greater CIE b* over NITRITE and CELERY (P < 0.05), while CHERRY had greater CIE b* than ERYTH and NONE (P < 0.05). IMMEDIATE processing with ERYTH created the most intense cured color indicated by the ratio of reflectance at 650 to 570 nm, followed by IMMEDIATE with CHERRY (P < 0.05), over all other treatment combinations. OVERNIGHT holding resulted in poorer color attributes compared to IMMEDIATE, regardless of curing or reducing agent, evidenced by lower CIE a* and chroma values (P < 0.05).

Conclusion: Alternative curing and reducing agents have minimal impacts on yield and texture attributes of direct acidified pork sausage. IMMEDIATE processing is advantageous over OVERNIGHT holding for yield and cured color, probably due to premature breaking of the encapsulation in the latter. Accordingly, the inclusion of ERYTH or CHERRY is recommended for achieving optimal cured color. The use of BEET and CHERRY increases yellowness of the sausages, likely owing to the pigmentation of the powders themselves, although CELERY was mostly similar to NITRITE.

Funding Source: This research received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors.

Keywords: alternative curing, cured meat color, holding period, sensory analysis, texture profile analysis

34 INNOVATING HYBRID BEEF-LENTIL BARS, AND THEIR PHYSICOCHEMICAL PROPERTIES AND SENSORY APPEAL

Y. Lin¹, Y. Ai¹, P. Shand^1,*, ¹Food and Bioproduct Sciences, University of Saskatchewan, Saskatoon, Canada *phyllis.shand@usask.ca

Objectives: Amid growing health and sustainability concerns, integrating plant-based proteins such as lentils into conventional meat products offers a nutritional enhancement without compromising flavor. This study aimed to assess the potential of the innovative integration of lentil flour into beef bars, focusing on physicochemical and sensory attributes.

Materials and Methods: Eston lentil seeds (10.6% seed moisture) were either tempered to target moisture content 25% or non-tempered (NT) then both infrared heated to inactivate deleterious enzymes, courtesy of InfraReady Products (1998) Ltd. Tempered seeds exhibited increased damaged starch content, indicative of higher starch gelatinization (HG). Beef outside rounds were trimmed, ground (3/8’’, 9.5 mm), then mixed with 6% (NT6, HG6), 12% (NT12, HG12), and 18% (NT18) lentil flours, with the inclusion of salt, brown sugar, soy sauce, acidulants, spices, and sodium nitrite. Mixtures were stuffed out as bar strips, then dried and cooked in a combi-oven to target water activity of 0.90. Treatment HG18 was attempted, but the mixture was too viscous for stuffing. A beef-only control (Con) was also produced. Cooked strips were equilibrated for 7 d before testing, and 3 replications of all treatments were prepared. Take-home evaluation packages were provided to 47 panelists. Numbers were limited due to sample availability and restricted gathering. Intensity, hedonic, and just-about-right scales were used. Results were analyzed by linear mixed models using R.

Results: Samples of all treatments reached an internal temperature of 72°C, with a pH below 5.3 and water activity under 0.90, aligning with Canadian regulations for shelf-stability. Cook losses were consistent across treatments, averaging 37%, with no significant (P < 0.05) differences observed. The introduction of lentil flour significantly (P < 0.05) reduced fat contents while enriching carbohydrate levels including fiber. Higher lentil flour addition (HG12, NT18) resulted in a significantly (P < 0.05) lighter (higher L* value) and more yellow (higher b* value) surface color than Con. Consumer panelists rated NT18 as the most yellow (P < 0.05), but also the lowest color acceptability (P < 0.05). Higher lentil flour addition (NT12, HG12, NT18) significantly (P < 0.05) increased Warner Bratzler shear values compared to HG6 and Con, while starch gelatinization showed little influence. However, panelists rated NT12 significantly (P < 0.05) firmer than HG12. NT18 beef-lentil bars exhibited greater (P < 0.05) stiffness by three-point bending test and was associated with significantly (P < 0.05) lower texture acceptability. Perception of dryness significantly increased (P < 0.05) with each 12% increment in lentil flour addition. No significant difference was found in aroma acceptability, flavor intensity, and acceptability across treatments. The overall acceptability of the hybrid beef-lentil bars remained comparable to Con (5.5–5.9 out of 8; 8 = like extremely).

Conclusion: This study underscores the promising role of lentil flour as a viable alternative protein in hybrid meat products, with overall acceptability remaining consistent across treatments. A 12% lentil flour inclusion emerged as the optimal level, closely mirroring the sensory attributes of beef-only control, and effectively addressing variations in color and texture. Starch gelatinization level did not influence most assessed parameters.

Funding Source: Saskatchewan Agriculture Development Fund

Keywords: consumer, dried meat snack, hybrid, lentil, texture

35 EFFICACY OF COMMERCIALLY AVAILABLE LOW-SODIUM ORGANIC ACID SALTS AGAINST LACTOBACILLUS SAKEI IN A CURED AND UNCURED TURKEY DELI MEAT

R. Furbeck^1,*, K. Rumbaugh¹, J. Saha¹, E. Heintz², S. Kumar¹, ¹Food Protection and Preservation, Kerry, Beloit, Wisconsin, United States, ²Food Protection and Preservation, Niacet - A Kerry Company, Tiel, Netherlands *rebecca.furbeck@kerry.com

Objectives: The aim of this study was to evaluate the efficacy of sodium and potassium based organic acid salts against Lactobacillus sakei in reformed turkey deli meat at refrigerated storage (4°C).

Materials and Methods: Reformed turkey deli meat was manufactured in 10 treatments (0.25%–0.75% potassium acetate/diacetate dry powder blend (Provian K), 1.25%–3.50% liquid potassium lactate/sodium diacetate commercial blend), 100 ppm sodium nitrite in the highest concentration of both antimicrobials, and uncured and cured (100 ppm sodium nitrite) control (no antimicrobial). Four 25-gram slices were placed into a vacuum bag and inoculated with (2.5–3.5 log10 CFU/g) L.sakei, vacuum packaged, and stored at 4°C for up to 42 d. At sampling timepoints, duplicate bags were removed from stored, homogenized, and plated onto deMan, Rogosa, Sharpe agar for enumeration of lactic acid bacteria. Samples were considered spoiled at 6 log10 CFU/g. Treatment performance was compared using ANOVA in SAS JMP 17. Significance in this study was set at (P < 0.05).

Results: Deli formulations with no antimicrobial had 77.66% moisture content and 0.9730–0.9732 water activity. Potassium acetate/diacetate formulations had 74.69%–77.23% moisture and water activity 0.9612–0.9690, while potassium lactate/sodium diacetate had 76.61%–77.45% moisture and 0.9654–0.9732 water activity. Inoculation level of 2.5–3.5 log CFU/g of L. sakei was achieved on day 0 for all treatments. Potassium acetate/diacetate blend (0.75%) greatly enhanced shelf life compared to control (which reached spoilage at 15 d), imparting 14 d of extension to 29 d. On day 29, the highest levels of potassium acetate/diacetate and potassium lactate/sodium diacetate commercial blend were significantly lower (P < 0.05) than all other treatments, exhibiting 5.68 log10 CFU/g and 5.75 log10 CFU/g respectively, while all other treatments had exceeded 7 log10 CFU/g.

Conclusion: Potassium acetate/diacetate blends can provide significant shelf-life extension in turkey deli meat systems contaminated with Lactobacillus sakei. Performance is comparable to commonly used commercial solution (potassium lactate/sodium acetate) but, as it is dry, at a use rate almost 5 times lower (0.75% compared to 3.50%). As microbial efficacy is equivalent at lower use rate, processors have a more sustainable option, requiring less freight for the same impact in product.

Keywords: frankfurter, lactic acid bacteria, processed meats, sodium reduction, spoilage

36 USE OF VINEGAR NATURAL FLAVOR SOLUTION TO CONTROL SPOILAGE ORGANISMS IN MECHANICALLY SEPARATED CHICKEN

R. Furbeck^1,*, J. Saha¹, E. Heintz², S. Kumar¹, S. Potkamp², ¹Food Protection and Preservation, Kerry, Beloit, Wisconsin, United States, ²Food Protection and Preservation, Niacet - A Kerry Company, Tiel, Netherlands *rebecca.furbeck@kerry.com

Objectives: The aim of this study was to evaluate the antimicrobial efficacy of a vinegar natural flavor solution (NouriShield D4010) in mechanically separated chicken.

Materials and Methods: Mechanically separated chicken (MSC) was obtained from a commercial abattoir, transported on refrigeration on day of production. Raw materials included skeletal portion from production of thighs, and chicken paws. At time of receiving, a baseline assessment of physiochemical attributes was conducted, including direct pH measure, and moisture content. The following treatments were prepared by blending ingredients of interest with MSC in a stand mixer: No preservative control, 0.6% vinegar solution (IsoAge DV 110), and 0.6% vinegar-natural flavor solution. Product was inoculated with 2–3 logs of Leuconostoc mesenteriodes to investigate spoilage organism control. Day of inoculation was referred as “Day 0”. The meat was placed into sampling bags and stored at 4°C over 4 d. Daily, duplicate samples were homogenized and plated onto deMan, Rogosa, Sharpe agar (MRS) for enumeration of lactic acid bacteria (LAB). Treatment effect was evaluated with one-way ANOVA in SAS JMP 17. Significance in this study is set at P ≤ 0.05.

Results: The mechanically separated chicken had a moisture content of 71% and pH of 6.72. On day zero, there was no significant treatment effect, as all treatments had approximately 4 log CFU/g LAB. The additional log of bacteria can be attributed to background microbes from the initial raw material. At day 2, the no preservative control exceeded the 6 log10 CFU/g spoilage limit, and the antimicrobial treatments were significantly (P ≤ 0.05) lower at 4.1–4.3 log10 CFU/g. At this time, the no-preservative control exhibited significant malodor, while antimicrobial treatments maintained odor typical of MSC. A significant (P ≤ 0.05) increase in growth was observed with other treatments on last day of testing (day 3), where vinegar-natural flavor treatment exhibited best performance at inhibiting outgrowth.

Conclusion: Currently, meat processors must consider the time-sensitive nature of MSC utilization due to its short shelf life as a raw material as high-water activity and free mineral content support microbial growth. This study suggests use of vinegar-natural flavor can mitigate outgrowth of Leuconostoc mesenteriodes in raw MSC, maintaining product organoleptic quality 33% longer than traditional organic acid systems, increasing flexibility in its utilization.

Keywords: antimicrobials, lactic acid bacteria, microbiology, poultry, raw materials

37 REPLACEMENT OF LACTATE-BASED SOLUTIONS WITH NO-SODIUM ALTERNATIVES IN A FRESH PORK SAUSAGE APPLICATION

R. Furbeck^1,*, J. Saha¹, M. McGough², R. Weyker², P. Ludtke², S. Kumar¹, ¹Food Protection and Preservation, ²Meat Applications, Kerry, Beloit, Wisconsin, United States *rebecca.furbeck@kerry.com

Objectives: This study was performed to determine antimicrobial solutions that can replace lactate-based solutions in fresh pork sausage microbial shelf life.

Materials and Methods: A no-antimicrobial control, 2.20% potassium lactate control, 0.50% potassium acetate/diacetate treatment, and 0.50% potassium acetate/diacetate with (0.30%) smoke fraction and (0.01%) natural flavor were chosen as treatments to evaluate performance of various antimicrobial in a fresh sausage system. Fresh pork trim was ground with ice water, seasoning blend, and antimicrobial fractions when applicable. Sausage batter was stuffed into collagen casings forming 25-g links. Four links were placed into polystyrene trays (CKF Inc., Rexdale, Ontario) and overwrapped. Product had starting pH of 6.11 ± 0.04, moisture content of 60.19 ± 2.64%, and salt (measured as percent chloride) of 1.11 ± 0.01%. Sausage was placed into dark storage at 4°C for evaluation of uninoculated shelf life. At each sampling timepoint, duplicate packages were removed from storage, sterile buffer added, and stomached. Dilutions were plated onto TSA for aerobic plate count and MRS for lactic acid bacteria, VRBA for Enterobacteriaceae, and CFC for Pseudomonas spp. TSA was incubated at 37°C for 48 h, MRS at 37°C for 48 h anaerobically, VRBA at 37°C for 24 h anaerobically, and Pseudomonas spp. at 25°C for 48 h. An additional subset of sausages was inoculated with Lactobacillus sakei. Using a sterile syringe, inoculum was injected into links, to provide 2–3 log10 CFU/g per package. The effect of treatment and day on microbial counts were evaluated in SAS JMP 17 using a generalized linear model. Significance in this study was set at P ≤ 0.05.

Results: There was a significant day by treatment interaction on all microbial counts tested. This can be attributed to all treatments having similar counts at the beginning and diverging separately throughout the experiment (Table 1). Microbial spoilage was delayed by all tested antimicrobials as the no antimicrobial control passed spoilage threshold (∼6 log10 CFU/g) at Day 16, and all antimicrobial treatments had significantly lesser (P < 0.0001) counts. At Day 18 of sampling, no spoilage defects were observed in antimicrobial containing treatments. On day 25, both antimicrobial treatments had visual mold, and thus sampling was concluded. Additionally, lactate and acetate-based solutions exhibited different dominant spoilage organisms. While the lactate samples outgrew with pseudomonads and Enterobacteriaceae, the acetate-based solution was dominated with lactic acid bacteria. The microbiome pivot to lactic acid bacteria is a favorable shift, as these genera tend to be less fastidious than the pseudomonads and less malodorous than the Enterobacteriaceae. It is, however, important to control these organisms as well, which can be assessed with the Lactobacillus sakei inoculated samples. At Day 16, the smoke fraction treatment had significantly less (P = 0.0002) outgrowth than the other treatments, exhibiting 3.69 log10 CFU/g, compared to 5.72–6.42 log10 CFU/g.

Conclusion: Potassium acetate/diacetate is a viable replacement for lactate-based antimicrobial in fresh pork sausage. Smoke fractions can provide additional protection against Lactobacillus sakei.

Keywords: acetate, fresh sausage, lactate, shelf-life, spoilage

38 THE EFFECT OF FAT CONTENT ON THE INACTIVATION OF LISTERIA INNOCUA IN MEAT EMULSIONS AFTER HIGH-PRESSURE PROCESSING

Y. Nino Fuerte^1,*, B. Wang¹, G. Sullivan², S. Shrestha³, M.-G. Danao¹, ¹Food Science and Technology, ²Animal Science, University of Nebraska-Lincoln, Lincoln, Nebraska, United States, ³Food Safety and Quality, Cargill Protein North America, Wichita, Kansas, United States *yninofuerte2@huskers.unl.edu

Objectives: High-pressure processing (HPP) is recognized by the United States Department of Agriculture Food Safety and Inspection Service (USDA FSIS) as a post-lethality method to treat ready-to-eat (RTE) meat and poultry products post-packaging to control Listeria monocytogenes (Lm). However, predictive microbial inactivation tools are still lacking and difficult to develop given HPP’s efficacy is sensitive to product formulation. A scoping review of the literature showed that the inactivation of Lm in RTE meat products with high fat content (>15%) by HPP was lower than in products with low fat content (<15%). However, because few researchers reported fat content and used a wide range of holding times (0.1 to 15 min) and temperatures (10 to 17°C), it was difficult to estimate the potential baroprotective effect by fat content. Hence, the aim of this study was to determine the effect of fat and pressure level on the inactivation of Listeria innocua (a surrogate for Lm) in meat emulsions.

Materials and Methods: A split-plot experiment, with pressure nested within fat content, was designed with over 90% power using a minimum detectable difference of 0.3 log reduction, leading to 5 replications. L. innocua Seeliger strains SLCC 3379 (ATCC No. 33090^™) and DUP-104 (ATCC No. 51742^™) were cultivated in tryptic soy broth (TSB) at 32°C, transferred twice every 24 h, combined into a 2-strain cocktail, and cold adapted at 15°C for 72 h. Afterwards, the cocktail was used to inoculate the surface of 25-g slice samples of pork meat emulsions with varying fat content (5% and 15%) with 2% salt, 0.35% sodium phosphate, 10% water, 156 ppm sodium nitrite, and 547 ppm sodium erythorbate (meat block basis). The inoculum level was 10⁶ to 10⁷ log CFU/g. Each inoculated sample was vacuum-sealed in a pouch, double-bagged, and kept refrigerated for 18 to 24 h. The samples were split into 4 groups according to pressure level, i.e., control (non-HPP), 300, 450, and 600 MPa, which was applied for 3 min (hold time) using chilled water (18°C). L. innocua populations were determined in control and HPP-treated samples using direct plate counts on tryptone soya yeast extract agar (TSYEA) incubated at 32°C for 48 h.

Results: There was a significant interaction (P < 0.0001) between fat content and pressure level on the inactivation of L. innocua. Similar to the results of the scoping review, at 300 MPa, the mean log reductions were not appreciable (<0.12 log) and not significantly different between 5% and 15% fat emulsions. At 600 MPa, reductions (>5 log) were also not significantly different between these two fat levels. However, at a moderate pressure of 450 MPa, reductions were significantly different (P < 0.01) between 5% fat (2.23 ± 0.29 log) and 15% fat (3.11 ± 0.11 log).

Conclusion: These results contradict the results of the previous scoping review in that the inactivation of L. innocua was found to be higher in 15% than in 5% fat meat emulsion although both are relatively lean. Future testing using 25% fat pork meat emulsions is planned to determine whether Listeria inactivation continues to increase with fat content or decrease, which may indicate there is a threshold where fat begins to provide a baroprotective effect.

Funding Source: Financial support was provided by the Department of Food Science and Technology and the Food Processing Center at the University of Nebraska-Lincoln.

Keywords: fat content, high-pressure processing, inactivation, Listeria monocytogenes, ready-to-eat meats

39 MODIFIED ATMOSPHERE PACKAGING COMPOSED OF HIGH OXYGEN, CARBON MONOXIDE, OR NITRIC OXIDE INFLUENCE GROUND BEEF COOKED COLOR, LIPID OXIDATION, AND RESIDUAL NITRITE AND NITRATE

B. J. Carpenter^1,*, T. W. Dobbins¹, M. S. Hernandez¹, S. N. Barker¹, K. R. Loomas¹, W. N. Osburn², J. F. Legako¹, ¹Department of Animal and Food Sciences, Texas Tech University, Lubbock, Texas, United States, ²Department of Animal Science, Texas A&M University, College Station, Texas, United States *Benjamin.Carpenter@ttu.edu

Objectives: The objective of this study was to evaluate the viability of nitric oxide as a novel gas type for ground beef modified atmosphere packaging (MAP) as compared to high oxygen and carbon monoxide through the evaluation of internal cooked color, lipid oxidation, and residual nitrite and nitrate at 3 time points of retail display.

Materials and Methods: Fifteen 4.5 kg chubs of fresh commodity ground beef were allocated to one of 3 MAP treatments: 80% O₂ and 20% CO₂ (HI-OX; n = 5), 0.4% CO, 30% CO₂ and 69.6% N₂ (CO; n = 5), or 0.4% NO and 99.6% N₂ (NO; n = 5). Each chub was ground, formed into 0.45 kg bricks, placed into MAP trays, and flushed with the designated gas. Packages equilibrated in the dark at 2 to 4°C for 48 h prior to display in coffin cases under fluorescent lighting. Samples were vacuum packaged and frozen at −20°C from times of 0, 72, and 120 h of the display. Samples were thawed in refrigeration for 24 h, formed into 150 g patties, and cooked to an internal temperature of 71°C on a flat-top gas grill. Internal cooked color was evaluated by 6-trained panelists using a 7-point scale where 1 = very red and 7 = tan/brown. Instrumental cooked color data of L*, a*, and b* values were also collected. The cooked patties and remaining raw samples were flash frozen and powdered. Raw samples were analyzed for thiobarbituric acid reactive substances (TBARS) through mg malondialdehyde/kg sample. Raw and cooked samples were used for determination of ppm of residual nitrite and nitrate. Data were analyzed as randomized block design with gas type, display time, raw/cook treatment if applicable, and their interaction as fixed effects and chub as the block. Significance was determined at P ≤ 0.05.

Results: There were no gas × time interactions for cooked color scores or instrumental cooked color data (P > 0.05). Gas type influenced cooked color score (P < 0.001) and a* values (P < 0.001), but these variables were not impacted by display duration (P = 0.365; P = 0.781). Ground beef held in NO was pink and had increased a* values (P < 0.05), while beef from CO and HI-OX packages were grayish tan/brown and had similar a* values (P > 0.05). There were no differences in cooked L* or b* values between gas types or display times (P > 0.05). Beef lipid oxidation, indicated by TBARS values, was varied due to gas type (P < 0.001) where malondialdehyde content of beef held in NO was 0.045 mg/kg, CO was 0.046 mg/kg, and HI-OX was 0.047 mg/kg (P < 0.05). Time did not influence TBARS values and there was no gas × time interaction (P > 0.05). Residual nitrite content was impacted by gas type and cooking (P = 0.009). Cooking increased nitrite for all gas types, and cooked NO samples had the most nitrite at 7.8 ppm while raw HI-OX samples had the least at 0.5 ppm (P < 0.05). Residual nitrate content varied due to a gas × time × cook interaction (P < 0.001). Cooked NO samples had the most nitrate and increased over time with 59.8 ppm nitrate at 120 h (P < 0.05). Raw samples had similar nitrate across gas types and display time (P > 0.05) but cooking increased nitrate for HI-OX and CO at 120 h at 18.9 and 11.9 ppm (P < 0.05).

Conclusion: Although NO packages had less TBARS values indicating a possible antioxidant effect, NO also had increased residual nitrite and nitrate. Additionally, NO packages had more red cooked color indicating potential for persistent pinking in cooked ground beef.

Keywords: carbon monoxide, cooked color, ground beef, modified atmosphere packaging, nitric oxide

40 EFFECT OF DEHYDRATION TIME ON SENSORY PROPERTIES OF JERKY-STYLE PET TREATS MADE FROM SWINE PLUCK

H. Carrera^1,*, I. Berganza¹, S. Bryne¹, C. Starkey², J. Starkey ¹, S. Cho¹, ¹Poultry Science, Auburn University, Auburn, Alabama, United States, ²Regulatory and Scientific Affairs, North American Renderers Association, Alexandria, Virginia, United States *hzc0125@auburn.edu

Objectives: The pet food industry is expected to experience a substantial growth, with pet food/treats identified as the leading category for expenditures among pet owners in the U.S. market in 2023. These products often incorporate meat animal processing co-products due to their relatively low market value combined with their high protein and nutrient content. Consequently, swine pluck (SP), a combination of heart, lungs, esophagus, and trachea, can serve as a viable protein source in pet food and treats due to its convenient single-unit removal during swine processing. Sensory parameters such as appearance, color, and texture can play a major role for pet owners when selecting products for their pets. Therefore, understanding human perception can be crucial for product marketability considering pet owners typically have the initial interaction with the product before providing it to their pet. The objective of this study was to evaluate the effect of dehydration time on various sensory characteristics of jerky-style treats made with SP.

Materials and Methods: To prepare samples, raw SP was ground using a 4.76-mm grinder plate, mixed with 1% sodium alginate and 0.85% encapsulated calcium lactate, extruded into jerky strips, and refrigerated for 16 h at 4°C to allow product gelation. Then, 3-inch jerky strip samples were dehydrated at 68°C for 3, 4, 5, 6, and 7 h. As expected, final water activity decreased linearly as dehydration time increased from 3 to 7 h (a_w = 0.94, 0.90, 0.86, 0.81, and 0.80, respectively; P < 0.05), and moisture content also decreased linearly and ranged from 49% to 17% (P < 0.05). Instrumental textural characteristics, CIE L*, a*, b* color, and color delta E values were also recorded. To assess consumer acceptability characteristics, 100 pet owners evaluated 5 jerky samples using a 9-point hedonic scale (1 = extremely dislike, 9 = extremely like) to assess the intent to purchase among pet owners as well as product overall liking, appearance, color, and texture using Red Jade software. Data were analyzed using a mixed model in XLSTAT 2023 version 3.1, with dehydration time as the fixed effect and participants as a random effect. Means were considered different when P ≤ 0.05. Pairwise comparisons were achieved using Tukey’s Honestly Significant Differences (HSD) test.

Results: Overall liking ratings for SP treats ranged from 5.01 to 5.61 (±0.238), and appearance ratings were between 5.11 and 5.30 (±0.20), while overall liking and appearance liking scores were similar among all SP jerky-style treats regardless of product dehydration time (P > 0.05). However, color liking scores among SP treats ranged from 4.60 to 5.08 (±0.15), while panelists preferred the color of SP treats dehydrated for 3 and 4 h over those dehydrated for 7 h (P < 0.05). Texture liking scores were between 4.19 to 5.65 (±0.30), and panelists preferred the texture of SP treats dehydrated for 4, 5, 6, and 7 h compared with those dehydrated for 3 h (P < 0.05). Among pet owners surveyed, the intent to purchase ratings were from 2.79 to 3.23 (±0.13), with least preference shown for SP jerky treats dehydrated for only 3 h (P < 0.05).

Conclusion: Overall, the sensory evaluation of jerky-style pet treats developed using SP provides insight into pet owners’ acceptability and purchasing decisions. Future work will focus on performing preference tests with both owners and their pets.

Keywords: sensory evaluation, color, pet treat, texture, swine pluck

41 PHYSICAL METHODS TO CONTROL TYROPHAGUS PUTRESCENTIAE INFESTATIONS ON DRY CURED HAM: UVC LIGHTING AND CARBOXYMETHYL CELLULOSE BASED FILMS

M. Bishop¹, M. Mosby¹, S. W. Smith^1,*, X. Zhang¹, Z. Molloy¹, G. Tang¹, E. Little¹, L. Zaldivar¹, T. Phillips², M. W. Schilling¹, ¹Department of Food Science, Nutrition and Health Promotion, Mississippi State University, Starkville, Mississippi, United States, ²Department of Entomology, Kansas State University, Manhattan, Kansas, United States *ssmithfoodscience.msstate.edu

Objectives: Tyrophagus putrescentiae is both the most common and the most difficult pest to control in the dry-cured ham industry. Ultraviolet radiation, specifically shortwave type C, shows promise as a physical means to control mite infestations on dry-cured ham. Additionally, carboxymethyl cellulose (CMC) films have also been effective at controlling mite infestations in benchtop studies. Therefore, the two objectives of this study were (1) To investigate the effect of varying Ultraviolet-C (UV-C) exposure times on the mortality rate of ham mites; and (2) To determine whether CMC-based films with various concentrations of glycerol and propylene glycol (PG) could prevent the growth and reproduction of mites on dry-cured hams.

Materials and Methods: (UV-C) In the first experiment, 3 treatments of complete darkness (control), LED white light, and UV-C light were set up in 3 chambers lined with aluminum foil. A 3 × 3 factorial structure within a randomized complete block (RCB) design with 3 replications (blocks) was used to evaluate the impact of light source (darkness, LED, UV-C) and exposure duration (5, 10, 15 min) on the mortality of mites (n = 5/treatment). Fifty adult mixed-sex ham mites were inoculated onto 1 cu. in. ham samples. Following inoculation, ham cubes were carefully placed directly under the light treatment and placed in a ventilated jar for 24 h, and then mobile mites were enumerated. (CMC) In the second experiment, treatment films consist of 1% CMC-based films containing glycerol (0%, 0.5%, 1.0%, 1.5%, and 2.0%) and PG (0% and 10%). An RCB design with 3 replications (blocks) was used to evaluate the impact of the films (n = 5/treatment) treatments. The films were prepared and wrapped around 1 cu. in. ham samples, with 20 large mixed-sex mites inoculated on each ham cube. A negative control (without film), a positive film control (1% CMC + 20% PG), and a positive net control (1% carrageenan + 1% propylene glycol alginate + 40% PG) were also included in the experiment. The ham cubes were placed in ventilated jars and incubated for 2 wk, after which mobile mites were enumerated.

Results: (UV-C) For the lighting treatments, interaction did not exist (P = 0.1582) between lighting and exposure duration. When averaged over exposure duration, the UV-C treatment resulted in a higher mortality rate of 74% (P = 0.0006) compared to the white LED treatment (29%) and the darkness treatment (27%). No time effect was observed (P = 0.7192) when averaged over different lighting. (CMC) For the films, results indicated that all treatments were effective (P < 0.0001) at controlling the mite population compared to the negative control (236 mites). The CMC-based glycerol and/or PG films were as effective (P > 0.05) as the positive film and net controls. The inclusion of glycerol or 10% PG did not (P > 0.05) improve the effectiveness of the CMC-only film at controlling mites, suggesting that the mite-controlling efficacy is primarily attributed to the physical barrier properties of the CMC-based films.

Conclusion: In conclusion, this study emphasizes the potential of both UV-C lighting and CMC-based films with glycerol inclusion as a tool for integrated pest management in the dry-cured ham industry. Future studies will seek to identify the optimal conditions for UV-C lighting as well commercial application of CMC-based films.

Funding Source: Funded by Mississippi State University’s Office of Undergraduate Research and Creative Discovery.

Keywords: edible film, integrated pest management, methyl bromide, stored products

42 DEFINING THE PARAMETERS OF HIGH-PRESSURE PROCESSING NEEDED TO IMPROVE DARK-CUTTING BEEF COLOR

A. Hahn^1,*, L. G. Venzor¹, S. A. Curry¹, G. C. Johnson¹, M.-G. Danao², R. Ramanathan³, J. C. Wicks¹, G. A. Sullivan¹, ¹Animal Science, ²Food Science and Technology, University of Nebraska-Lincoln, Lincoln, Nebraska, United States, ³Food and Animal Sciences, Oklahoma State University, Stillwater, Oklahoma, United States *ahahn17@huskers.unl.edu

Objectives: Persistent issues with dark-cutting beef have inflicted ongoing losses on the beef industry, underscoring the necessity for mitigation strategies. Previous research noted that high-pressure processing (HPP; 300 MPa) has been observed to improve dark-cutting beef color by increasing the redness and lightness value. However, limited knowledge is currently available on the effect of holding time and lower levels of pressure application on the surface color of dark-cutting steaks. Therefore, the objective of this study was to define the parameters of pressure (MPa) and time (s) needed for achieving improved color and appearance of dark-cutting beef using HPP.

Materials and Methods: Eight USDA Choice normal pH (mean pH = 5.6) and 10 dark-cutting (mean pH = 6.6) strip loins were obtained from a commercial beef packing plant that were identified as dark at the time of grading. Five days after initial collection, loins were cut into 5 equal sections (approximately 6.35 cm), vacuum packaged, and randomly assigned to a HPP treatment. Loins were randomly assigned one of 3 pressures: 240, 300, or 450 MPa, and subsequent sections were assigned to one of 5 hold times (in s): 0 (no HPP, control), 1, 30, 60, and 90. Following 48 h of dark storage, loin sections were cut into 3 steaks. One 2.54-cm steak from each section was overwrapped with a polyvinyl chloride (PVC) film and placed in a Styrofoam tray for a 7-d retail display. Instrumental surface color was measured in triplicate on days 0, 3, and 7 with a Minolta CR-400 colorimeter (Minolta, Osaka, Japan) (Illuminant D65) for L*, a*, and b*. The data were analyzed using the GLIMMIX procedure of SAS 9.4 (SAS Institute, Cary, NC, USA) by pressure for the main effects of holding time and dark-cutting classification using a randomized complete block design with loin considered a random effect.

Results: There was no dark-cutting classification by holding time interaction effect for any pressure for day 0 (P > 0.05) except 240 MPa for b* (P = 0.042). For the main effect of HPP holding time on day 0, no differences were observed in L* and a* values at a pressure of 240 MPa at any of the 5 hold times. However, normal pH HPP treated loins had greater b* values (P < 0.05) than all other treatments except the dark-cutting 90-s HPP holding time treatment. At 300 MPa, loin sections subjected to a 90 s hold time had increased (P < 0.05) L* values (lightness) from that of control. Similarly, both a* and b* values also resulted in higher values for sections held for 90 s compared to the control and a hold time of 1 s. Applying HPP at 450 MPa increased lightness (L*), redness (a*), and yellowness (b*) values (P < 0.05), regardless of hold time compared to the control, which had the lowest values for each. On day 3 and day 7 of retail display, similar color trends were identified. For the main effect of dark-cutting classification, high-pH dark-cutting loins had lower L*, a*, and b* values for all HPP pressures regardless of holding time.

Conclusion: These results indicate that a pressure of 300 MPa can increase the L* and a* values, improving the color of dark-cutting beef when held for 30 s or more. Loins subjected to 240 MPa showed little effect. At 450 MPa, loin sections were lighter and more red, but the treatment may result in excessive lightening resulting in a negative visual appearance.

Keywords: beef color, dark-cutting beef, holding time, high-pressure processing

43 AMINO ACID TYPE AND CONCENTRATION IMPACT ON ENDOTHELIAL NITRIC OXIDE ENZYME IN RESTRUCTURED HAMS

A. Reeves^1,*, M. Alnajrani¹, N. Broz¹, A. Harrison¹, T. Wright¹, W. Osburn¹, ¹Animal Science, Texas A&M University, College Station, Texas, United States *arliereeves99@tamu.edu

Objectives: The objective of this study was to determine the effects of amino acid type and concentration on the ability of endothelial nitric oxide (eNOS) enzyme to effectively cure restructured hams.

Materials and Methods: Boneless pork semimembranosus (IMPS 402F) and pork biceps femoris (IMPS 402D) muscle were ground (1/3 through kidney plate, 1/3 through 1.27 cm plate, 1/3 through 0.48 cm plate) and mixed with a 20% brine consisting of 9% salt, 5.75% sugar, 1.75% sodium tripolyphosphate, 550 ppm sodium erythorbate with either 200 ppm sodium nitrite (control) or an amino acid (Arginine [Arg], Citrulline [Cit], Arginine/Citrulline Combination [AC]) at varying concentrations (1000, 3000, 5000 ppm). Meat was hand mixed with brine treatments, double bagged (60% vacuum) then placed into vacuum tumbler at 137895 Pa (20 psi) going 9 rpm for 30 min. Treatments were stuffed into 6.35 cm pre-stuck fibrous casings (0.45 kg chubs) clipped and thermally processed (71.1°C) and chilled (4.4°C) within 10 h. Chubs were vacuum packaged with casings on in high oxygen barrier (Oxygen transmission rate = 2 to 5 cc/100 in²/24 h) packaging and placed in 4.4°C storage until day of analysis (1, 7, 28, and 56) for pH, L* a* b* values, thiobarbituric acid reactive substances (TBARS), residual nitrate (RNO₃), residual nitrite (RNO₂), and nitroslyhemochromagen (NO-Heme). On d 28, a trained sensory panel and objective textural attributes were analyzed. This study was a factorial (3 amino acids × 3 concentrations) randomized complete block design with a nitrite control (200 ppm), 2 samples per treatment and replicated twice. Least-squares means and Tukey’s HSD were conducted with a P < 0.05 significance.

Results: An amino acid × concentration interaction (P = 0.0001) was observed for RNO₃. Trends suggested 1000 ppm concentration for amino acid treatment combinations resulted in higher NO₃ values. The main effects of amino acid type and concentration did not affect RNO₂ values in the restructured hams; however, all amino acid treatments produced ∼1/3 of the amount of RNO₂ of nitrite control and values were stable over d 56 storage. An amino acid type × concentration interaction (P = 0.01) was observed in NO-Heme values as well as an amino acid × storage day interaction (P = 0.001), with Arg ham treatments having similar NO-Heme values as nitrite control. Amino acid type influenced cured ham ID (P = 0.004) and ham flavor aftertaste (P = 0.006), with Arg exhibiting scores similar to the nitrite control. Amino acid type also affected soured aromatic (P = 0.03) and chemical/medicinal/metallic (P = 0.001), with Cit and Arg/Cit treated ham having the highest values for both attributes. An amino acid × concentration (P = 0.0001) interaction was observed for objective hardness values, with Arg treated ham values increasing as concentration increased (1000 to 5000 ppm) and exhibiting values similar to the nitrite control.

Conclusion: Arg effectively cured restructured hams via the eNOS enzyme compared to Cit treatments based on NO-heme and sensory analysis. A concentration of 1000 ppm was sufficient for generating nitric oxide via the eNOS enzyme. Further research should be conducted to evaluate the specific flavor profiles generated by amino acid–treated hams.

Funding Source: This work was funded by USDA-NIFA AFRI under Grant Number 2021-09606.

Keywords: None

44 AMINO ACID TYPE AND CONCENTRATION IMPACT ON VOLATILE COMPOUNDS PRODUCED BY ENDOTHELIAL NITRIC OXIDE SYNTHASE ENZYME IN RESTRUCTURED HAMS

L. Reiling^1,*, A. Reeves¹, C. Kerth¹, W. N. Osburn¹, ¹Animal Science, Texas A&M University, College Station, Texas, United States *lreiling35@gmail.com

Objectives: To determine the effect of amino acid type and concentration on the ability of the endothelial nitric oxide synthase enzyme to produce similar volatile compounds as conventional curing in restructured hams.

Materials and Methods: Boneless pork semimembranosus muscle (IMPS 402F) and pork biceps femoris muscle (IMPS 402D) were ground (1/3 through kidney plate, 1/3 through 1.27 cm plate, 1/3 through 0.48 cm plate) and hand mixed with a 20% brine consisting of 9% salt, 5.75% sugar, 1.75% sodium tripolyphosphate, 550 ppm sodium erythorbate, and either 200 ppm sodium nitrite (control) or Arginine (Arg), Citrulline (Cit), or Arginine/Citrulline (Arg/Cit) Combo at concentrations of 1000, 3000, and 5000 ppm. After mixing, the treatments were doubled bagged, sealed (60% vacuum) and vacuum tumbled (137895 Pa at 9 rpm) for 30 min. Using a hand crank stuffer, 0.45 kg of each treatment was stuffed into 6.35 cm pre-stuck fibrous casings. Treatments were thermally processed to an internal temperature of 71.1°C and chilled to 4.4°C (< 10 hr.). After chill, the hams were vacuum packaged (casings on) in a high oxygen barrier (Oxygen transmission rate = 2 to 5 cc/100 in²/24 h) bag and stored at 4.4°C until day of analysis. On day 28 of storage, samples were flash frozen in liquid nitrogen and pulverized using a Waring blender. Ham samples were analyzed by gas chromatography/mass spectroscopy (GC/MS) to determine volatile compounds associated with sensory characteristics. For volatile analyses, frozen samples (along with 10 μl of 1,3-dichloro-benzene as an internal standard) were placed in a 20 mL glass vial in a heating block (60°C) for 30 min. Then a PDMS-Carboxen solid-phase microextraction (SPME) sampler was inserted into the vial to absorb the volatile compounds for 20 min. The SPME was then inserted into the injection port of a 7820 Agilent gas chromatograph (GC), where compounds were desorbed for 3 min and then released onto a 30 m BPX5 capillary column. Following a temperature ramp (7°C per min) of the GC, volatile compounds were separated and proceeded to an Agilent 5975 mass spectrometer (MS) for identification and quantification. This study was analyzed as a completely randomized design with nitrite source and level as fixed effects.

Results: GC/MS analysis yielded 24 significant volatile compounds between the ham treatments, with 11 alkanes, 4 cycloalkanes, 1 alkene, 1 benzene, 1 amide, 1 monoterpenoid, 1 aromatic compound, and 1 inorganic compound. The Arg/Cit combination treatment, at 1000 ppm, was significantly different (P < 0.05) for 15 volatile compounds when compared to the other treatments. The aromatic/flavor descriptions of most compounds reported are unknown. Heptanal is known for producing a strong, harsh, pungent odor with an unpleasant and fatty taste. The decanal compound can have a sweet, floral, and citrus like fatty odor and flavor. Finally, the volatile compound acetone is known for its pungent odor and slightly sweet taste. Each of these compounds were significantly higher (P values of 0.0421, 0.0065, and 0.0001, respectively) in the Arg/Cit combination treatment at 1000 ppm.

Conclusion: From this study we can conclude that the Arg/Cit combination treatment at the lowest concentration (1000 ppm) had significantly higher concentrations of volatile compounds undesirable for sensory characteristics.

Funding Source: This work was funded by the USDA-NIFA AFRI under Grant Number 2021-09606.

Keywords: endothelial nitric oxide synthase, GC/MS, L-arginine, L-citrulline

45 EVALUATION OF GROUND BEEF COLOR STABILITY UNDER NITRIC OXIDE-MODIFIED ATMOSPHERE AND TRADITIONAL PACKAGING SYSTEMS

E. S. Neal^1,*, T. W. Dobbins¹, B. J. Carpenter¹, S. N. Barker¹, M. S. Hernandez¹, R. Ramanathan², J. C. Brooks¹, D. R. Woerner¹, J. F. Legako¹, ¹Animal and Food Sciences, Texas Tech University, Lubbock, Texas, United States, ²Animal and Food Sciences, Oklahoma State University, Stillwater, Oklahoma, United States *elizneal@ttu.edu

Objectives: The objective of this study was to evaluate the performance of ground beef in nitric oxide-modified atmospheric packaging (MAP) in comparison to traditional packaging technologies.

Materials and Methods: Thirty chubs of 80:20 ground beef (±4.53 kg) were obtained from a commercial purveyor and randomly sorted into 8 batches. Each batch was coarse ground and immediately formed into 0.45 kg bricks. Bricks were randomly assigned to 1 of 5 packaging types: Vacuum (VAC, n = 40), Polyvinyl Chloride overwrap (PVC, n = 40), 80% O2:20% CO2 (HI-OX, n = 40), 0.4% CO:30% CO2: 69.6% N2 (CO, n = 40), or 0.4% NO:99.6% N2 (NO, n = 40). Bricks designated for MAP systems were placed into 2.5 cm deep plastic trays and flushed with their designated gas. Packages were acclimated for 7 d at 0 to 2°C in the dark. After storage, samples designated to PVC were removed from vacuum and overwrapped. All samples were then placed in a simulated retail display, where descriptive and instrumental color were evaluated every 12 h for 96 h. Descriptive color was evaluated by 6 trained panelists using an 8-point scale where 1 = very bright red and 8 = tan to brown, and discoloration was characterized as a percentage in a range of 0–100. Instrumental color was evaluated using a HunterLab spectrophotometer. Surface myoglobin redox forms metmyoglobin (MMb), deoxymyoglobin (DMb), and oxymyoglobin (OMb) were quantified based on spectral data from 474, 530, 570, and 700 nm wavelengths. Data were analyzed as a randomized block design with repeated measures, where packaging type, display time, and their interaction served as fixed effects. Significance was determined at P ≤ 0.05.

Results: An interaction of packaging type × display time impacted a* values (P < 0.001). At 0 h of display, a* values were lowest among HI-OX packages followed by VAC, NO, PVC and CO (P < 0.05). However, after 96 h of display, while HI-OX packages still exhibited the lowest a* values, redness among NO packages increased with time, which was similar to CO especially when compared to PVC and VAC packages (P < 0.05). Furthermore, an interaction of packaging type × display time was observed for descriptive color (P < 0.001), where HI-OX packages from 84 to 96 h were tan to brown (P < 0.05) and CO packages from 0 to 96 h were bright red (P < 0.05). In comparison, throughout display PVC and HI-OX packages exhibited an increase in color score while CO and NO packages both decreased. This is similar to discoloration which was also impacted by a packaging type × display time interaction (P < 0.001). More specifically, at 0 h NO packages exhibited the greatest percentage of discoloration, yet after 96 h NO packages exhibited less discoloration than PVC and HI-OX packages. Likewise, a packaging type × display time interaction (P < 0.001) occurred for MMb, where surface MMb percentages in both CO and NO packages generally decreased from 0 h to 96 h of display.

Conclusion: While ground beef packaged in a CO system maintained the most redness and little discoloration, NO packages increased in a* value, and inherently became more red throughout retail display. With further optimization of a nitric oxide-modifed atmosphere, NO systems could provide a packaging solution to promote redness with prolonged retail display period.

Funding Source: Research coordinated by the National Cattlemens’s Beef Association, a contractor to the Beef Checkoff.

Keywords: ground beef, nitric oxide, packaging

46 EFFECTS OF CITRUS FIBER ON TEXTURE AND WATER-HOLDING CAPACITY OF WOODEN BREAST CHICKEN NUGGETS

M. J. Nawaz^1,*, H. Thippareddi², B. Bowker³, H. Zhuang³, D. Chatterjee³, A. M. Stelzleni¹, ¹Animal and Dairy Science, ²Poultry Science, University of Georgia, Athens, Georgia, United States, ³U.S. National Poultry Research Center, USDA, Agricultural Research Service, Athens, Georgia, United States *junaidnwz@hotmail.com

Objectives: The wooden breast (WB) myopathy causes substantial revenue loss to the poultry meat industry. Wooden breast is described by excessive adipose and connective tissue deposition leading to hardness and diminished water-holding capacity (WHC). Utilizing WB in further processed products is an avenue for value addition. However, incorporating WB in ground products (meatballs and patties) diminished product quality. Citrus fiber was reported to ameliorate texture and WHC of normal chicken patties and meatballs. This study aimed to determine if citrus fiber could improve WHC and textural properties in WB chicken nuggets.

Materials and Methods: Across 3 replications 450 kg of normal and severe woody breast fillets were selected 4 h postmortem from a local commercial broiler facility and transported on ice to the University of Georgia Meat Science and Technology Center. Collected breasts were individually evaluated by manual palpation and visual characterization to confirm normal and severe WB characteristics. Breasts were coarse (1.27 cm) ground and separated into six 11.34 kg batches based on WB content resulting in 2 batches each for 0% WB (WB0), 50% WB (WB50), and 100% WB (WB100). One out of the 2 batches had 0.1134 kg (1%) replaced with citrus fiber resulting in 3 treatment batches with fiber (F) and 3 without fiber (NF). A 2.5% spice blend (0.75% NaCl, 0.65% sucrose, 0.6% onion powder, 0.3% garlic powder, and 0.1% white pepper and paprika) and 10% water was added into each of 6 batches and finely (0.48 cm) ground. Batters were extruded through a three-slot die (0.95 × 3.17 cm) attached to vacuum stuffer to form nugget strips. Strips were subjected to blast-freezing (−40°C) for 30 min and cut into 5 cm long nuggets. Five sets of nuggets (3 nuggets each) per treatment within each replication were randomly selected, vacuum packaged, and frozen for sensory and texture analyses. Data were analyzed as a Randomized Complete Block Design with 2 × 3 factorial arrangements using MIXED procedure of SAS 9.4. Woodiness (WB) and fiber inclusion (FIB) were the fixed effects, and replication was the random term.

Results: Wooden breast blends had different pH (P < 0.01), where WB0 had the lowest pH followed by WB50 and WB100. Fiber inclusion improved cook yield (P < 0.01) by 6.4, 8.5, and 8.9%, respectively, for WB0, WB50, and WB100. There were WB×FIB interactions for shear energy (P < 0.01) but not for shear force (P > 0.05). Fiber incorporation mitigated shear energy and force (P > 0.05) differences between WB0, WB50, and WB100 nuggets, and the nuggets required less energy and force (P < 0.01) to shear than nuggets without fiber. There were WB×FIB interactions for hardness, chewiness, and springiness (P < 0.01). No fiber WB0 were harder and chewier than WB100 nuggets (P < 0.01), but there was no difference in hardness or chewiness (P > 0.05) of FIB incorporated WB0, WB50, and WB100 nuggets, and nuggets with fiber were softer, chewier, and less springy (P < 0.01). Sensory analysis revealed that nuggets with fiber, irrespective of the WB level, were softer, chewier, and less springy (P < 0.01), without affecting sweetness, sourness, juiciness, and spice complex (P > 0.05), but had greater salt detection (P < 0.01).

Conclusion: Fiber inclusion in nuggets formulated with WB meat improved cooking yield and mitigated textural differences without affecting flavor attributes except saltiness.

Funding Source: USDA, National institute of Food & Agriculture (NIFA), Agriculture & Food Research Initiative (AFRI)

Keywords: citrus fiber, wooden breast

47 IMPACT OF MAILLARD REACTION TO MINIMIZE PERSISTENT PINKING IN COOKED GROUND BEEF

M. Goswami^1,2, R. Kumar^1,*, M. Pfeiffer¹, G. Mafi¹, V. Pathak², R. Ramanathan¹, ¹Animal and Food Sciences, Oklahoma State University, Stillwater, Oklahoma, United States, ²Department of Livestock Products Technology, C.V.Sc.&A.H., DUVASU, Mathura, India *rishav.kumar@okstate.edu

Objectives: Persistent pinking refers to a pink color in cooked meat (undercooked appearance) after cooking to a USDA-recommended temperature. A greater than normal postmortem meat pH is considered the most important contributing factor for persistent pinking. This phenomenon can cause consumer concerns as the cooked color deviates from a brownish color. Maillard reaction and myoglobin denaturation are two important reactions that contribute to brown color in cooked meat. The Maillard reaction involves the reaction between a reducing sugar (such as glucose) and an amine side chain containing amino acid (such as lysine) when heated at high temperatures. However, limited studies have considered enhancing Maillard reaction to minimize undercooked appearance in high-pH beef. The objective of the present study was to determine the effects of lysine and glucose on the cooked color of high-pH beef.

Materials and Methods: In the current research, the pH of ground beef was increased to 6.4 by adding phosphate solution. Different combinations of glucose and lysine were added in samples, i.e., C (control): pH 5.8 with 0% glucose and 0% lysine; T1: pH 6.4 with 0% glucose and 0% lysine; T2: pH 6.4 with 0% glucose and 1% lysine; T3: pH 6.4 with 0.5% glucose and 0.5% lysine; T4: pH 6.4 with 1% glucose and 0% lysine respectively. After mixing, 100 g patties were weighed and formed by hand using a KitchenArt Adjust-A-Burger Press. The patties were cooked to internal temperatures of 71°C on a George Foreman clam-shell grill. After cooking, both surface and interior color were measured using a HunterLab MiniScan spectrophotometer. Browning index (reflectance at 630 nm ÷ reflectance at 580 nm), myoglobin denaturation, and Maillard reaction products were also determined. The experiment was replicated 4 times (n = 4). The data were analyzed using the Mixed Procedure of SAS and considered significant at P < 0.05.

Results: Interior and exterior of patties from normal pH beef (C) patties were brown in color, while high-pH patties without the addition of any glucose or lysine had greater (P < 0.05) redness (a* values). In support, high-pH patties without lysine or glucose had lower myoglobin denaturation than normal-pH patties. Interestingly, adding lysine and glucose reduced the cooked redness of high-pH patties. Further, there were no differences in cooked color between lysine or glucose-added patties and normal-pH beef. However, there were no differences (P > 0.05) in internal cooked redness between different combinations of glucose and lysine (T2, T3, and T4). Maillard reaction products were formed more (P < 0.05) in 1% lysine than other treatments.

Conclusion: The addition of glucose or lysine in high-pH beef patties reversed the undercooked appearance. The study suggests that adding naturally present ingredients such as glucose or lysine can minimize cooked color defects in ground beef. Maillard reaction often improves flavor; hence, conducting sensory analysis and also using them in other processed meat products will help maximize their application in the meat industry.

Keywords: cooked meat color, Maillard reaction, myoglobin denaturation, persistent pinking

48 L-ARGININE CONCENTRATION, CURING METHOD, AND LOCATION IMPACT ON ENDOTHELIAL NITRIC OXIDE ENZYME IN PORK BACON

T. Wright^1,*, W. Osburn¹, M. Alnajrani¹, A. Reeves¹, N. Broz¹, A. Harrison¹, L. Reiling¹, ¹Animal Science, Texas A&M University, College Station, Texas, United States *wrighttanner@hotmail.com

Objectives: Previous research has determined that the endothelial nitric oxide (eNOS) enzyme can effectively cure post-rigor pork in benchtop studies. This study was done to determine the effects of L-Arginine (Arg) concentration on the ability of endothelial nitric oxide (eNOS) enzyme to effectively cure pork bacon with different curing methods and location.

Materials and Methods: Six boneless skinless pork bellies (IMPS 409) were portioned (anterior, middle, and posterior) with 2 of each being randomly assigned into curing agent treatments (1000 ppm Arg, 3000 ppm Arg, and 120 ppm nitrite [control]), with each applied to 2 curing methods (injected and vacuum tumbled). Bellies were combined with a 10% brine consisting of 18% salt, 5.5% sugar, 2500 ppm sodium tripolyphosphate, 550 ppm sodium erythorbate, and the assigned curing agent treatment. Brine was injected using a 4-needle hand injector and pumped to 12% then given a 2 h dwell time to achieve final 10% pump. Vacuum tumbled samples were combined with the 10% brine in a vacuum bag sealed at 80% vacuum, tumbled at 137895 Pa (20 psi) and 6 rpm for 2 h, then removed from the bag for thermal processing. Belly portions were thermally processed to 54°C with a 30 min dwell time, and chilled to ≤4°C within 10 h. Bellies were sliced (at 3 mm) and packaged with 6 slices per bag in high oxygen barrier (Oxygen transmission rate = 2 to 5 cc/100 in²/24 h) packaging. Samples were stored at 4°C until day of analysis (d 1, 7, and 28) for residual nitrate (RNO₃), residual nitrite (RNO₂), nitroslyhemochromagen (NO-Heme), and 2-thiobarbituric acid reacting substances (TBARs). RNO₂, RNO₃, and NO-Heme analyses were conducted with excised lean from sample slices. This study was a factorial (2 concentrations × 3 belly locations × 2 curing methods) + 1 nitrite control randomized block design and was replicated twice (n = 18). Least-squares means and Tukey’s HSD were conducted with a P < 0.05 significance. The nitrite control served as a reference and was not included in the statistical analysis.

Results: Arg concentration (P < 0.0001) impacted RNO₂ values with 1000 ppm having lower values (1.19 ppm) than 3000 ppm (1.5 ppm). Day (P < 0.0001) impacted RNO₂ values with values increasing from day 7 (1.06 ppm) to day 28 (1.67 ppm). Day (P = 0.004) impacted RNO₃ with values decreasing from day 7 (7.68 ppm) to day 28 (4.93 ppm). Day (P = 0.01) impacted NO-heme with values increasing from day 1 (5.56 ppm) to day 28 (7.56 ppm). Curing method (P = 0.0025) impacted TBARS values with injected samples having higher values (0.105 ppm) than tumbled samples (0.086 ppm). Although statistically significant differences were found for RNO₂, RNO₃, NO-Heme, and TBARs across treatment main effects, these differences are not of practical significance. Across all analyses when compared to the nitrite control, the Arg treatments exhibited (P < 0.0001) lower in value for RNO₂, RNO₃ and NO-Heme.

Conclusion: Although statistically significant differences were exhibited between arginine concentrations and curing method, values being similar (within 1 ppm) suggest they do not make a practical difference. Results of this study indicate 1000 ppm Arg is sufficient for the eNOS enzyme to generate NO across all locations (anterior, middle, and posterior) and curing method (injected or tumbled) to develop cured meat attributes expected in bacon.

Keywords: endothelial nitric oxide synthase, L-arginine, nitroslyhemochromagen, residual nitrate, residual nitrite

49 EFFICACY OF SOLUBILIZED MYOFIBRILLAR BEEF PROTEIN AS A MEAT BLOCK COMPONENT IN ALL-BEEF FRANKFURTERS

M. Cropp¹, K. Robbins^1,*, M. Stender¹, ¹Food Technologies North America, Kemin Industries, Des Moines, Iowa, United States *michael.cropp@kemin.com

Objectives: The study objective was to determine the impact of solubilized myofibrillar beef protein as a meat material with and without alkaline phosphate for effects on the shelf life, processing, and quality attributes of all-beef frankfurters.

Materials and Methods: Five all-beef frankfurter formulations (75% beef/25% water and non-meat ingredients) were manufactured: a conventional all-beef meat block with (1 “0CP”) and without (2 “0CNP”) alkaline phosphate, an all-beef meat block containing 4% replacement by solubilized myofibrillar beef protein (Proteus® B010) with (3 “4SP”) and without (4 “4SNP”) alkaline phosphate, and (5) an all-beef meat block containing 8% replacement by solubilized myofibrillar beef protein (Proteus® B010) without alkaline phosphate (“8SNP”). All formulations included salt, corn syrup, spices, rosemary extract, buffered vinegar powder, sodium erythorbate, and sodium nitrite. The formulations were vacuum chopped and stuffed into inedible cellulose casing, thermally processed to 71°C, chilled to <4°C, peeled, vacuum packaged, and stored under refrigerated storage conditions at 3°C for analysis over shelf life. Properties evaluated included cooked and chilled yield, microbial analysis (30-d increments from d 0 until logarithmic growth exceeds 6 log CFU/g) and, on days 27 and 82, instrumental internal and external color (L*, a*, b*), texture (hardness, chewiness, resilience, cohesiveness, springiness, and incisor puncture analysis), and sensory properties including appearance, flavor, juiciness, and acceptability. The study was replicated twice, with replications (n = 2) produced on consecutive days. Statistical analysis of formulation and day (main effects) and two-way interactions using STATGRAPHICS Centurion 18 software with significance determined at P < 0.05, trending P values were determined where 0.05 ≤ P < 0.01.

Results: No significant differences (P > 0.05) for cooked and chilled yield were observed among formulations. Microbial growth of spoilage bacteria via total plate count (TPC) and lactic acid-producing bacteria (LAB) were not significantly different (P > 0.05) across any formulation. Instrumental texture for chewiness, hardness, and incisor puncture analysis were significantly greater (P < 0.05) for phosphate-containing formulations. Sensory panelists who evaluated samples twice found no significant differences between samples or over storage time for any criteria evaluated (appearance, flavor, juiciness, acceptability). A trend (P = 0.059) for overall acceptability to decrease over storage time was observed for all formulations. Instrumental external and internal color properties (L*, a*, b*) were not significantly different (P > 0.05) for any formulation. Instrumental internal L* and internal b* resulted in a significant day effect where L* increased and b* decreased over storage time. Additionally, across all formulations, a trend (P = 0.080) for internal a* to increase over storage time was found.

Conclusion: The present study’s findings demonstrate that solubilized myofibrillar beef protein can be included as a meat block component without any adverse effects on product performance or quality attributes during shelf life. This study showed that formulations with alkaline phosphates resulted in a firmer product texture by texture analysis but did not result in higher cook yield or any sensory differences.

Keywords: phosphate, processed meats, sensory, shelf-life, texture

50 IMPACT OF UV-A DEHYDRATION ON THE QUALITY OF BEEF JERKY

M. Alruzzi^1,*, C. D. stafford¹, S. K. Matarneh¹, ¹Nutrition, Dietetics, and Food Sciences, Utah State University, Logan, Utah, United States *mohammed.alruzzi@usu.edu

Objectives: Drying is a popular preservation method that inhibits bacterial growth and extends the shelf life of foods. Various food drying methods exist, including hot air drying, freeze drying, microwave drying, osmotic drying, and ultraviolet (UV) light drying, each with its advantages and limitations. UV light in the A spectrum (UV-A) is an effective non-thermal drying method that remains unexplored within the meat industry. Jerky is a cured and dried meat typically made with lean beef cuts. It is usually dehydrated in a smokehouse to attain a water activity (aW) of 0.85 or lower. This study aimed to compare the effects of thermal (smokehouse-oven) and non-thermal (UV) drying methods on the physicochemical properties of beef jerky.

Materials and Methods: To achieve this objective, 3 select top-round subprimals of similar weight were purchased from a local beef processing plant. Thirty-two strips of similar dimensions (3.5 × 1.25 × 0.2 in) were obtained from each top-round and weighed. Subsequently, sodium nitrite (40 mg/kg), erythorbate (550 mg/kg), and salt (15 g/kg) were added to the strips, thoroughly mixed, and incubated overnight in a refrigerator. The next day, 16 strips from each top-round were dehydrated in a smokehouse oven for 60 min, while the remaining 16 were dehydrated under UV-A light for 5 h. These parameters were chosen to standardize moisture content between the two drying methods. After dehydration, strips were re-weighed and used for moisture content, water activity (aW), color evaluation, shear force, and lipid oxidation analysis. The moisture content of the dried strips was evaluated with a microwave moisture analyzer, while a water activity meter was utilized to assess aW. Color analysis was achieved with a colorimeter, and tenderness was evaluated using a Warner-Bratzler shear force V-notch blade. Finally, lipid oxidation was determined by measuring thiobarbituric acid reactive substances (TBARS). Data were analyzed using the mixed model of SAS, with P ≤ 0.05 considered significant and P ≤ 0.10 regarded as a tendency.

Results: There were no significant differences observed in aW, moisture content, or TBARS between the two drying methods. More importantly, TBARS values obtained with both drying methods remained below the levels typically detectable by consumers. However, UV-dried jerky tended to be tougher compared to those dried in the smokehouse (P ≤ 0.10), with greater L*, and lower b* values (P ≤ 0.05). Redness also tended to be greater in the UV group compared to those that were oven-dried (P ≤ 0.10).

Conclusion: Overall, our results demonstrate that UV drying can be used to produce beef jerky and has potential for future use. However, it is essential to optimize both texture and color while also exploring consumer acceptability.

Keywords: beef jerky, drying, lipid oxidation, ultraviolet, water activity

51 ANALYSIS OF BACON LEAN COLOR STABILITY UNDER LIGHTED RETAIL DISPLAY, USING TWO PACKAGING ENVIRONMENTS WITH NOVEL BRINE INGREDIENTS

S. Beary^1,*, J. D. Manternach¹, K. R. Eivins¹, T. A. Houser¹, ¹Animal Science, Iowa State Unviersity, Ames, Iowa, United States *stephani@iastate.edu

Objectives: The objective of this study was to conduct two experiments using CIE (Commission Internationale de I’EClairage) lightness (L*), redness (a*), and yellowness (b*) values to analyze color degradation in bacon over time under lighted retail display given 3 brine treatments. One experiment was conducted for aerobic overwrapped packaging, and one experiment was conducted for anaerobic vacuum packaging.

Materials and Methods: The project analyzed bacon from 31 different bellies. The bellies were randomized into 3 different brine treatments involving a Control brine (CON), a curing brine with an added Rosemary Green Tea extract (RGT) (Fortium RGT-WS 1200, Kemin Food Technologies, Inc., Des Moines, IA), and a curing brine with an added natural Smoked Sugar (SS) (RA12032, Red Arrow Products, Manitowoc, WI). The curing brines were formulated for 15% uptake, and bacon was thermally processed using a commercial smokehouse schedule. The bacon slabs were then sliced and randomly assigned into overwrap packaging or vacuum packaging formats and replicated twice. The bacon packages were then randomly placed onto wire rack shelving under light-emitting diode (LED) lighting (1800 to 2500 lux) at 0 to 2°C. The bacon slices were rotated at each data collection to limit variability in light intensity. CIE L*, a*, b* values were evaluated in both the primary and secondary lean in overwrapped packaging 9 times over a 20-h retail light display including 0, 2, 5, 6.5, 8, 9, 10, 11, and 20 h. Vacuum packages were evaluated in both the primary and secondary lean 6 times over a 52-h retail lighted display including 0, 8.5, 18.5, 30, 40, and 52 h. The data were then analyzed using the PROC MIXED procedures of SAS version 9.4.

Results: The overwrapped bacon showed a decrease (P < 0.0001) in L* values over time in both the primary and secondary lean with no difference (P > 0.05) in the brine treatment. The a* values in the overwrapped bacon displayed a decrease (P < 0.05) over time in both the primary and secondary lean with no difference (P > 0.05) in the brine treatment. The b* values in the overwrapped bacon showed a decrease (P < 0.05) over time in both the primary and secondary lean. The b* values in the overwrapped bacon treated with SS were higher (P < 0.05) than the CON and RGT throughout the storage period in both the primary and secondary lean. The vacuum-packaged bacon L* values displayed a decrease (P < 0.05) over time in both the primary and secondary lean with no difference (P > 0.05) in the brine treatment. The vacuum-packaged bacon a* values showed an increase (P < 0.05) over time in both the primary and secondary lean with no difference (P > 0.05) in brine treatment. The b* values of the vacuum-packaged bacon showed a decrease (P < 0.05) over time in both the primary and secondary lean. The b* values in the vacuum-packaged bacon treated with SS were higher (P < 0.05) than the CON and RGT throughout the storage period in both the primary and secondary lean.

Conclusion: The color of the overwrapped bacon faded during the 20-h storage period regardless of brine treatment in both the primary and secondary lean. Interestingly, all vacuum-packaged treatments demonstrated improvement in red pigment over the 52-h storage period in the primary and secondary lean.

Funding Source: Funding was provided through the Iowa Pork Producers Association.

Keywords: bacon, color, lighted retail display, rosemary green tea, smoked sugar

52 IMPACT OF L-ARGININE CONCENTRATION ON ENDOTHELIAL NITRIC OXIDE SYNTHASE CURING OF BEEF JERKY USING TWO VALIDATED THERMAL PROCESSES

N. Broz^1,*, T. Wright¹, M. Alnajrani¹, A. Reeves¹, A. Harrison², L. Reiling¹, W. N. Osburn¹, ¹Animal Science, ²Food Science, Texas A&M University, College Station, Texas, United States *nick_2019@tamu.edu

Objectives: The study objective was to determine the impact of L-arginine (Arg) concentration on the ability for endothelial nitric oxide synthase (eNOS) system to cure beef jerky and its effect on product attributes using two validated thermal processes.

Materials and Methods: Boneless beef semimembranosus (IMPS 169A) were tempered (−10°C) for 60 min, sliced (6.5 mm) and trimmed (6.5 cm × 12 cm) for uniform strips. Strips were sorted into eight (1.7 kg) batches, one of 3 Arg concentrations (1000, 3000, and 5000 ppm) or the sodium nitrite control (156 ppm) for either low or high thermal processing (4 bags for each process). Treatments were placed in a vacuum bag with brine solution consisting of 12.5% salt and 20% sugar formulated and added (10%). The bag was sealed, double bagged and sealed at 80% vacuum. Jerky was vacuum tumbled for 30 min at 8 rpm at 137895 Pa (20 psi), bags were held (4°C) overnight to equilibrate. Batches were removed from bags laid onto non-stick drying racks and thermally processed to water activity (<0.85) using either low (Type 1B; max dry bulb 65.5°C) or high Type 1B (max dry bulb 87.8°C) thermal processing. Surface temperature (T) and relative humidity were monitored for the entire cook. Samples were then vacuum packaged in high oxygen barrier bags and stored (4°C) until analysis (day 1 and 28) for 2-thiobarbituric acid reacting substances (TBARS), hunter scan colorimeter (L* a* b*), pH, and water activity. Residual nitrate (RNO3), residual nitrite (RNO2), and nitroslyhemochromagen (NO-H) were analyzed on day 7 and 28 of storage. Data were analyzed using a one-way ANOVA to compare the treatments for each independent thermal process (Two studies). Least-squares means and Tukey’s HSD were used with a predetermined P < 0.05 significance. The control served as a reference and was not included in the statistical analysis.

Results: Arg concentrations for both thermal processes did not impact NO-H values (P > 0.05). Day of storage (P < 0.05) decreased NO-H (∼50%) from day 7 to 28 for both thermal processes. No differences were noted for concentration or day for RNO3 values for either thermal process. Concentration had no effect on RNO2 for low T processing but the main effect of day increased values (P < 0.0001) from day 7 (0.63 ppm) to 28 (2.45 ppm). RNO2 values for high T processing were different (P < 0.05) for 1000 and 5000 ppm Arg concentrations. Day (P < 0.0001) impacted RNO2 values increased from day 7 (0.94 ppm) to 28 (3.64 ppm). Although statistical differences were found for RNO2 across concentrations and day for each thermal process, the values suggest no practical differences. a* values were not significantly different for either main effect or thermal processing type among Arg treatments but were all lower than the control. However, TBARS values were similar to the control regardless of concentration, day of storage, or thermal process.

Conclusion: Arg treated samples showed no significance between concentration for any analysis with the exception of RNO2 values at 1000 and 5000 ppm. It was observed that high T treated samples tended to have slightly higher values for NO-H, a*, RNO3, and RNO2 compared to low T processing. Values for NO-H and a* values decreased as storage day increased similar to the control. Results from this study suggest that 1000 ppm Arg treated beef jerky thermally processed at a higher T results in a product that is more similar to the nitrite control.

Keywords: endothelial nitric oxide synthase, L-arginine, residual nitrate, residual nitrite, thermal processing

53 DEVELOPMENT OF DRY AGED BEEF CHARACTERISTICS USING STARTER CULTURES AND DRY AGING BAGS

Z. Hoelscher^1,*, M. G. Chapman¹, S. B. Tindel¹, K. B. Gehring¹, J. W. Savell¹, ¹Animal Science, Texas A&M University, College Station, Texas, United States *zachary.hoelscher@yahoo.com

Objectives: The objective of this study was to determine the impact of Debaryomyces hansenii and Lactobacillus sakei as starter cultures during aging of beef in selectively permeable bags designed to produce traditional dry aged characteristics.

Materials and Methods: The effects of starter cultures and specialty dry aging bags on quality traits lean color, aroma, yield, and pH were evaluated. Forty strip loins were purchased from a local distributor and cut in half, widthwise. Initial color was evaluated using an 8 member trained panel. Objective color was assessed using a Minolta MiniScan and pH was measured before aging. Loin sections were divided into 4 treatment groups: (1) control group with no starter culture, (2) inoculation with D. hansenii, (3) inoculation with L. sakei, (4) inoculation with a mixture of both D. hansenii and L. sakei. Samples were bagged, sealed, and aged in a 2°C cooler for 35 d. Upon completion of the aging period, the 8-member trained color panel assessed color. Additionally, a 9-member trained aroma panel identified the presence of the following 5 key aroma attributes: beef identity, bloody/serum, metallic, sour dairy, and spoiled. Final pH and objective color was also measured. Loin weights were recorded before and after aging, and after facing and trimming to food service standards. After facing and trimming, a 2.54 cm steak was removed from each loin, bagged, and stored in refrigerated conditions (2°C) for subsequent cooking. Pre and post cook weights were used to calculate cook yields of steaks.

Results: No significant differences in final color were observed between treatments when evaluated by a trained color panel. Additionally, there were no significant differences between treatments for aroma attributes or instrumental color values (P ≥ 0.05). Although not significant, treatment 2 had the highest numerical score for beef identity when evaluated by a trained aroma panel, as well as the highest numerical L* value. Treatment 1 had the highest final pH of 5.601 which was significantly different from treatments 2 and 3 (P = 0.0096). Furthermore, there were no significant differences among cook yields between treatments; however, treatment 2 observed the lowest numerical cook yield at 82.9%.

Conclusion: The results of this study indicated that the use of D. hansenii and L. sakei had no significant impact on most evaluated characteristics. A difference in pH was noted with D. hansenii treatment. L. sakei tended to vary from other treatments, possibly indicating some difference in effect. Based on these data, it is anticipated that this method of aging would result in less moisture and trim loss, resulting in higher yields than traditional dry aged products. This aging method could serve as a potential solution for high-end restaurants and consumers hoping to customize their beef-eating experience. The use of selectively permeable bags and the isolation and manipulation of starter cultures could allow for the development of desirable aroma and flavor characteristics in the finished product.

Keywords: aging, beef, packaging, quality, starter culture

54 NITRIC OXIDE SYNTHASE ENZYME AS AN ALTERNATIVE CURING SYSTEM IN UNCOOKED, FERMENTED, AND DRIED SALAMI

A. Harrison^1,*, W. Osburn², M. Alnajrani², T. Wright², N. Broz², A. Reeves², L. Reiling², ¹FSTC, ²ANSC, Texas A&M University, College Station, Texas, United States *abharrison97@tamu.edu

Objectives: The study ojbective was to assess the impact of L-arginine concentration and pH on endothelial nitric oxide synthase (eNOS) to cure uncooked, fermented, and dried salami (UFD Salami).

Materials and Methods: Six 2.27 kg batches of a pork/beef mix (60:40) (25% fat) were prepared. The meat was ground (12.7 mm), and a salami preblend seasoning with 1.25% sodium erythorbate, 2% salt, and 1% dextrose was added. Butylated hydroxytoluene (200 ppm) and anhydrous citric acid (28 ppm) were also added. Each batch was then treated with either 156 ppm sodium nitrite (Control) or L-arginine (Arg) at various concentrations of 1000, 2000, 3000, 4000, 5000 ppm (1k, 2k, 3k, 4k, 5k). After hand mixing (2 min), a lactic acid starter culture diluted in 0.5% H₂O was added and the batch reground (4.76 mm) and stuffed in 38 mm fibrous casings with 30 chubs/treatment (0.22 kg/chub). The chubs were fermented for 12 h at 37°C to a pH <5.0, then dried 3 d at 18°C and 80% AUTHOR: Please define if appropriate.RH and then for 8 d at 18°C and 70% RH until reaching a water activity of ≤0.920. Chubs were vacuum packaged with casings on and stored at 4.4°C until day of analysis (d 1, 14, and 28 of storage) for pH, residual nitrate (RNO₃), residual nitrite (RNO₂), nitroslyhemochromagen (NOh), Hunter L*a*b*, and thiobarbituric acid reacting substances (TBARS). This study used a randomized block design to analyze data from 5 Arg concentrations. Three replications were run. Least-squares means and Tukey’s HSD was used with a predetermined P < 0.05 significance. The control was used as a reference and not included in statistical analyses.

Results: Arg concentration did not affect RNO₃. The highest value was at 2k (0.58 ppm) and lowest at 4k (0.43 ppm). Day of storage significantly affected (P < 0.05) RNO₃, with day 1 (0.75 ppm) higher than day 28 (0.31). Arg concentration also did not effect RNO₂ values, with the highest value at 5k (0.08 ppm) and lowest at 1k (0.06 ppm). Day of storage did not affect RNO₂. Arg concentration significantly affected (P < 0.05) NOh values, with 4k (10.61 ppm) higher (P < 0.05) than 5k (8.51ppm). Arg concentrations had no effect on TBARS with the highest at 2k (1.42) and lowest at 5k (1.24). Day of storage significantly affected TBARS (P < 0.05), increasing from day 1 (0.98) to day 14 (1.16) and again on day 28 (1.50). Elevated TBARS may be due to frozen raw materials (jowls) used for manufacture since higher values were seen in both the Arg and the Control. Arg concentration affected pH with values increasing as concentration increased. All Arg groups differed significantly (P < 0.05) with mean pH’s of 4.76, 4.82, 4.86, 4.92, and 4.99 for 1k to 5k, respectively. The 5k had the highest a* (12.75). Day of storage (P < 0.05) increased a* values from day 1 (11.37) to day 14 (12.19). Control values were higher than all Arg treatments for RNO₂, RNO₃, NOh, and a* values; were lower for TBARS; and had a pH of 4.8.

Conclusion: Results show that Arg concentration does have a minor impact the eNOS system’s ability to cure UFD salami. RNO2 levels were unaffected by Arg concentration. RNO3 levels were about 1/6th of the control, with no clear impact from Arg concentration. Low RNO3 and RNO2 may result from pH-induced oxidation, indicated by high TBARS values. NOh and a* increased at higher concentrations (4k and 5k). In conclusion, higher Arg concentrations such as 4k and 5k may be suitable for curing UFD salami as they produced increased a* values and NOh levels and had minimal impact on pH drop during fermentation.

Keywords: endothelial nitric oxide synthase, fermentation, L-arginine, nitroslyhemochromagen

55 MACERATION FREQUENCY ALTERS SURFACE AREA, COOKING LOSS, AND PALATABILITY OUTCOMES OF CUBED STEAKS

K. Lawrence^1,*, M. E. Eckhardt¹, L. W. Lucherk¹, T. E. Lawrence¹, ¹Agriculture, West Texas A&M University, Canyon, Texas, United States *kelawrence1@buffs.wtamu.edu

Objectives: The objective of this study was to test the effect of mechanical maceration at 1, 2, or 3 frequencies on surface area, purge loss, and objective tenderness of eye of round and bottom round steaks.

Materials and Methods: Beef eye of round (n = 12) and bottom round muscles (n = 12) were aged 28 d postmortem. From each muscle, 8 steaks were cut and randomly assigned to 0, 1, 2, or 3 macerations and raw or cooked slice shear force (SSF) tenderness determinations. Steaks were trimmed to a common size (50 cm² for eye of round and 80 cm² for bottom round). Maceration was accomplished with a commercial steak tenderizer, then digital images were captured for surface area analysis. Steaks were weighed before and after maceration and again after vacuum-packaged aging to determine purge losses. Data were analyzed via mixed ANOVA models using a randomized complete block design.

Results: Surface area increased (P < 0.01) by 15.4%, 38.6%, and 62.4% for eye of round steaks and 22.0%, 51.3%, and 70.3% for bottom round steaks after 1, 2, or 3 macerations. Purge losses did not differ due to maceration for eye of round steaks (P = 0.25; 4.25%–4.86%) or bottom round steaks (P = 0.83; 5.88%–6.19%). Raw SSF values for eye of round steaks were decreased (P < 0.01) by 6.6%, 19.5%, and 40.0% after 1, 2, and 3 macerations; however, cooked SSF values only tended to differ (P = 0.08; 18.7–21.3 kg). For bottom round steaks, raw SSF values were decreased (P < 0.01) by 32.0%, 45.5%, and 67.2% after 1, 2, and 3 macerations; cooked SSF values for steaks that passed 1 or 2 times through the macerator were decreased (P = 0.02; 27.7–29.7 kg) by 7.7%, and bottom round steaks macerated 3 times were 30.4% more tender. Cooking losses were greater (P < 0.01) for macerated eye of round steaks (5.4%–7.2% greater) and macerated bottom round steaks (7.6%–10.8% greater). Cooking time was faster (P = 0.08) for eye of round and bottom round steaks (P = 0.04) macerated 3 times compared to other maceration frequencies and no maceration. Cooking decreased (P < 0.01) eye of round and bottom round SSF values by 56.3% and 42.0%, respectively. Maceration increases surface area and improves tenderness but does not tenderize muscles equally. Maceration decreased (P < 0.001) sensory initial juiciness and sustained juiciness and decreased connective tissue ratings (P < 0.001). Maceration increased (P < 0.001) sensory tenderness ratings, but the frequency of maceration did not impact (P ≥ 0.135) sensory tenderness.

Conclusion: Maceration increases surface area and improves tenderness but does not tenderize muscles equally.

Funding Source: Funded by the West Texas A&M University Beef Carcass Research Center.

Keywords: beef round, maceration, sensory, surface area, tenderness

56 VARIATION IN MEAT QUALITY BETWEEN THREE PIG MUSCLES ACROSS TWO AGEING TIMES IS NOT ASSOCIATED WITH POSTMORTEM METABOLIC ENZYME ACTIVITY

H. Huang^1,*, M. Hastie¹, R. Hewitt², D. D’Souza², H. Grigg³, R. Morrison³, F. Dunshea¹, M. Trezona⁴, R. Warner¹

¹School of Agriculture, Food and Ecosystem Sciences, The University of Melbourne, Parkville, ²SunPork Solutions, SunPork Group, Eagle Farm, ³Rivalea (Australia) Pty Ltd, JBS Australia Pork Division, Corowa, ⁴Linley Valley Pork, Craig Mostyn Group, Wundowie, Australia *huilinghstudent.unimelb.edu.au

Objectives: The study objective was to investigate the impact of pork muscle type on water-holding capacity (WHC) and tenderness across two ageing times and the relationship between metabolic enzyme activities and meat quality.

Materials and Methods: N = 73 pig carcases were sampled from two suppliers. Three hours postmortem, core samples were collected from biceps femoris (BF), longissimus thoracis et lumborum (LTL), and triceps brachii (TB); samples were immediately frozen and stored at −80°C until enzyme activity determinations. The muscles were collected at 24 h postmortem for meat quality measurements. Meat quality was assessed after 1 d and 13 d of ageing. Drip loss was measured by EZ-DripLoss method (weight loss over 48 h at 0 to 2°C, % of initial weight). Cook loss samples (55 ± 5 g) were cooked to internal temperature of 70°C and cooled, and cook loss percent was calculated from weight loss after cooking. Instrumental tenderness was measured using Lloyd Instruments LRX Materials Testing Machine (Lloyd Instruments Ltd, Hampshire, UK) with 0.63 mm diameter probe by double-bite compression for hardness. Activities of citrate synthase (CS) and lactate dehydrogenase (LDH) were determined as markers of glycolytic metabolism and oxidative capacity, using the protocol from Scheffler et al. (2014) and a commercial assay kit from Sigma (#Catalog: MAK066), respectively. Mixed linear modelling was performed on the quality measures using GenStat (16th Edition, VSN International, Hemel Hempstead, UK) with a fixed model: muscle and ageing time and their interaction. Enzyme activity fixed model included muscle only.

Results: The LTL had lower CS activity and higher LDH activity at 3 h postmortem (P < 0.001 for both) whereas BF and TB had similar CS and LDH activity (P > 0.05). Drip loss was much lower for the LTL and BF after 13 d ageing compared to 1 d ageing, whereas TB had similar and low drip loss after 1 d and 13 d ageing (P < 0.001). Cook loss increased with ageing for LTL (P < 0.01), but did not change with ageing for BF and TB (P > 0.05). Hardness was much higher for the BF than for the LTL and TB (P < 0.001). After 13 d ageing, the BF and LTL showed similar hardness values compared to 1 d ageing (P > 0.05), whereas the hardness of the TB markedly decreased (P < 0.001).

Figure 1.

Effect of muscle (biceps femoris BF longissimus thoracis et lumborum LTL. triceps brachii TB). on citrate synthase (CS) activity and lactate dehydrogenate (LDH) activity on samples collected at 3 hours post-mortem (p < 0.001 for both). The SED is shown as a line above and below the mean.

Conclusion: BF and TB were similar in metabolic enzyme activity but were different in WHC and hardness values. Thus, although BF, LTL, and TB differed in WHC and hardness, this was not associated with differences in muscle oxidative and glycolytic enzyme activity. Further research is needed to understand the influence of muscle metabolism on inconsistency in meat quality.

Funding Source: Australian Pork Limited is gratefully acknowledged for funding this project.

Keywords: None

57 REDUCED EXPRESSION OF RIBONUCLEOTIDE REDUCTASE SUBUNIT M2 IN MUSCLE AND SEVERAL ORGANS POTENTIALLY ALTERED TISSUE HEALTH AND MITOCHONDRIA FUNCTION IN WOODY BREAST CHICKENS

M. Shakeri^1,*, J. Choi¹, C. Harris¹, R. J. Buhr¹, B. Kong¹, H. Zhuang¹, B. Bowker¹, ¹USDA-ARS, U.S. National Poultry Research Center, Quality & Safety Assessment Research Unit, Athens, Georgia, United States *majid.shakeri@usda.gov

Objectives: The aim of this study was to investigate the role of ribonucleotide reductase enzyme subunit M2 (RRM2) and associated pathways related to mitochondria function and ATP production in severe woody (WB) and normal (N) breast muscles and other potentially related organs.

Materials and Methods: In total 30 birds (15 N and 15 WB) were selected for sampling. Pectoralis major samples and organs (duodenum, jejunum, ileum, and liver) were excised from 8-wk-old male broilers immediately postmortem and fixed in liquid nitrogen. Quantitative PCR was performed to determine gene expression using SYBR green, and commercial kits were used for biochemical assays. Student’s t-tests were used for comparison of the two groups using Prism (GraphPad software). Results were considered significant at P ≤ 0.05. Mean values are given as mean ± SE.

Results: Histology assessment (Picrosirius red) confirmed WB categorization and showed increased fibrosis (P = 0.006) in WB muscle samples. Results showed that RRM2 activity (P = 0.0002) and RRM2 expression (P = 0.05) were reduced in WB compared to N muscle samples. Furthermore, RRM2 expression was reduced in duodenum (P < 0.0001) and liver (P = 0.01), but no significant changes were observed in ileum and jejunum. In muscle tissues, expression of genes related to mitochondria function including ATP synthase membrane subunit 6 (essential for normal mitochondrial function, P = 0.03), NADH dehydrogenase 2 (mitochondrial respiratory chain, P = 0.001), and hydroxymethylbilane synthase (impaired oxygen transport and metabolism, P = 0.002), were reduced in WB. Muscle samples with the WB myopathy tended to have elevated expression of caveolin 3 (defected membrane integrity, P = 0.09), endoglin (increased fibrosis, P = 0.06) and secreted protein acidic and rich in cysteine (metabolic dysregulation, P = 0.09). Aspartate-aminotransferase-mitochondria activity (P = 0.02) pyruvate kinase concentration (P = 0.04), DNA damage (P = 0.06), creatine kinase concentration (P = 0.05), and triglyceride concentration (P = 0.002) were increased for WB, while ATPase activity (P = 0.01) was decreased in WB muscle tissues.

Conclusion: In conclusion, differences in data indicating mitochondria dysfunction and increased DNA damage suggest that RRM2 mediated mitochondrial abnormalities may play an important role in the woody breast myopathy.

Keywords: woody breast, DNA damage, digestive system, ribonucleotide reductase activity, mitochondria

58 ALTERNATIVE AGING AND COLD STORAGE STRATEGIES INFLUENCE BEEF SHELF-LIFE AND SENSORY ATTRIBUTES

M. N. Wootton^1,*, C. R. Shaw¹, J. B. Van Buren¹, Y. Guo¹, J. A. Nasados¹, P. D. Bass¹, M. J. Colle¹, ¹Animal, Veterinary, and Food Sciences, University of Idaho, Moscow, Idaho, United Statesmwootton@uidaho.edu

Objectives: Discoloration and retail shrinkage cost the beef industry billions of dollars annually. However, identifying other cold storage strategies for beef subprimals could reduce these losses to the industry. The objective of the current study was to determine the effects of alternative aging strategies and cold storage management on shelf-life and sensory attributes of longissimus thoracis (LT) and gluteus medius (GM) steaks.

Materials and Methods: Beef carcasses were fabricated at 24 h postmortem. At 4 d postmortem, boneless beef lip-on ribeye rolls (n = 32; IMPS 112A) and boneless beef top sirloin butts (n = 32; IMPS 184B) from USDA Choice carcasses were randomly assigned to one of 4 treatments and were aged for 35 d postmortem. Treatments included control (2°C; C), suspended fresh (−1.5°C; SF), blast freezing (−20°C; BF), and flash freezing (packed in dry ice, frozen storage at −20°C; FF). Frozen subprimals were thawed (2°C) on day 32, and fluid loss of all subprimals was determined on day 35. Steaks were cut (2.54 cm) and analyzed for objective color (L*, a*, and b*), subjective color, lipid oxidation, and consumer sensory analysis. Statistical analysis was conducted in the MIXED procedure (SAS V9.4). Significance was determined at P < 0.05.

Results: Refrigeration treatments resulted in less fluid loss following aging as opposed to freezing treatments for both ribeye rolls (P < 0.01) and top butts (P < 0.01). In both subprimals, BF resulted in the greatest fluid loss. Differences between aging treatments were observed for L* (P < 0.01) and a* values (P < 0.01) of LT steaks. Control LT steaks had the highest L* values across all 3 d of retail display, while FF steaks maintained the lowest L* values. Suspended fresh LT steaks had the highest average a* values, while FF steaks maintained the lowest throughout retail display. Differences between aging treatments were observed for a* values (P < 0.01) of GM steaks. Suspended fresh and C GM steaks had the highest a* values. An interaction was observed between aging treatment and day of retail display for subjective scores for oxygenated lean color of LT (P < 0.01) and GM steaks (P < 0.01). Suspended fresh LT and GM steaks maintained the brightest, most cherry-red colored lean through day 3 of retail display. Lipid oxidation exhibited an aging treatment by day of retail display interaction for LT steaks (P < 0.01) and GM steaks (P = 0.04). Control steaks from both muscles had the highest TBARS values by day 3 of retail display, and FF steaks maintained the lowest TBARS values through day 3 of retail display. Aging treatment influenced panelists’ overall acceptability scores, which revealed that acceptability was lowest among FF LT (P < 0.01) and GM steaks (P < 0.01). In summary, across all 3 d of retail display, refrigeration treatments led to steaks with higher a* values, and freezing treatments led to lower levels of lipid oxidation.

Conclusion: Freezing treatments can be utilized to mitigate oxidation in foodservice markets, but refrigeration treatments will result in greater consumer appeal at the retail level. Alternative aging and cold storage strategies can improve potential profits for the beef industry.

Funding Source: Research coordinated by the National Cattlemen’s Beef Association, a contractor to the Beef Checkoff.

Keywords: aging, color, fluid loss, freezing, lipid oxidation

59 COMBINING MUSTARD MEAL AND POTATO EXTRACT IMPROVES SHELF LIFE AND PALATABILITY IN PRECOOKED BEEF PATTIES

P. Ebrahimi^1,*, I. Popova², J. Nasados¹, J. Van Buren¹, M. Wootton¹, C. Shaw¹, Y. Guo¹, R. Haggerty³, P. Bass¹, M. Colle¹, ¹Department of Animal, Veterinary and Food Sciences, University of Idaho, Moscow, Idaho, United States, ²Department of Soil Science, University of Wisconsin, Madison, Madison, Wisconsin, United States, ³College of Agricultural and Life Sciences, University of Idaho, Moscow, Idaho, United States *pebrahimi@uidaho.edu

Objectives: Employing water binders in beef patties can increase juiciness and extend frozen shelf life. Some water binders currently used by the meat industry are considered allergens or “non-natural” ingredients. Mustard, a non-allergenic and natural ingredient, is an excellent reservoir of antioxidants. The objective of this study is to improve yields and minimize the warmed-over flavor using mustard meal and potato extract in precooked beef patties.

Materials and Methods: Water binder treatments included 1% potato extract (positive control), 1% potato extract in combination with 0.25% mustard meal extract, 1% potato extract in combination with 1% mustard extract, and no binder added (negative control). Six batches of each treatment were made using USDA Choice boneless beef chuck shoulder clod purchased from a commercial processing facility. Each batch included 4.53 kg of ground beef, 15% water, 1% salt, 0.2% onion granules, and the designated binder treatment. Beef chucks were coarse ground through 10 mm plate, fine ground through 3 mm plate, mixed for 2.5 min at 29 rpm using DMX-50 Daniels 50 lb mixer, and formed using a Patty-O-Matic 330A patty former into 16-mm-thick patties. The lean-to-fat ratio was analyzed and measured at 84:16, and each patty weighed 151 g. Two patties from each batch were analyzed for each analysis. Patties were cooked to 170°F on a clamshell grill, stored in a −4°F freezer for 180 d, and reheated in a 360°F oven. The fluid loss percentage during cooking (cook loss) was calculated. Lipid oxidation was measured using Thiobarbituric Acid Reactive Substances (TBARS) assay on raw, cooked (day 0), frozen, and reheated (day 180) patties. Additionally, the pH of the raw, cooked (day 0), and reheated (day 180) patties were measured. Data were analyzed using a linear model in the R program 4.3.3 version. Binder treatment, cook status (raw vs. cooked beef patties), and their interaction were considered fixed effects and batch a random effect, with a significance level of P < 0.050.

Results: There was a difference between treatments for cook loss (P < 0.001). Patties containing potato extract and mustard meal extract reduced cook loss compared to the negative and positive control. There was a binder treatment by cook status interaction for patty lipid oxidation (P < 0.001). Lipid oxidation increased in the cooking process to a greater extent in the negative control than the other binders. There was no binder treatment by cook status interaction for patty pH (P = 0.104). While there was no binder treatment difference (P = 0.381), pH for cooked patties differed from raw patties (P < 0.001). The pH increased with cooking.

Conclusion: Using mustard meal extract in combination with potato extract reduces cook loss and therefore could enhance consumers’ eating experience of pre-cooked beef patties. Furthermore, lipid oxidation is reduced in the cooking process when there is a water binder added to beef patties. This leads to a higher quality product, a reduction in food waste, and potentially an increase in profits for the meat industry.

Funding Source: We gratefully acknowledge financial support from the National Institute of Food and Agriculture (NIFA) and USDA.

Keywords: cook loss, mustard meal extract, pre-cooked beef patties, warmed-over flavor

60 IMPACT OF THE VISUAL SEVERITY OF DARK-CUTTING ON WET-AGED BEEF LONGISSIMUS LUMBORUM STEAK PALATABILITY AND SENSORY ATTRIBUTES

M. A. Scott^1,*, K. Harr¹, G. G. Mafi¹, R. Ramanathan¹, M. Pfeiffer¹, ¹Department of Animal and Food Sciences, Oklahoma State University, Stillwater, Oklahoma, United States *grace.harris@okstate.edu

Objectives: Surface color of beef is often linked to wholesomeness in the minds of consumers, and therefore any deviation from the consumer preferred bright-cherry red lean color can lead to meat products being discarded, resulting in economic losses to the industry. Dark-cutting (DC) beef presents an unconventional, dark-colored lean that strays from the consumer preferred color. The severity of DC in the ribeye (longissimus dorsi) at the time of grading can vary among carcasses and could potentially impact palatability. Thus, the objective of this study was to evaluate the impact of visual severity of DC on the eating quality of wet-aged beef longissimus lumborum steaks.

Materials and Methods: Beef strip loins (n = 8/treatment) were collected from commercial beef packing plants and selected based on the visual severity of DC in the ribeye. Strip loins corresponding to selected carcasses were allocated to treatments as follows: mild, moderate, and severe DC, and a normal bright cherry-red (BCR) colored control. Loins were fabricated 48 to 60 h postmortem and were bisected. Loin halves were randomly assigned to either a 21 or 39 d wet-aging period. Upon completion of aging, each loin half was sliced into 2.54 cm thick steaks. Steaks were randomly assigned to trained sensory panel and consumer sensory panel analyses. Trained panelists and untrained consumer panelists evaluated steaks for palatability and sensory attributes on 8-point hedonic scales. Samples were cooked using a Rational® oven to a peak internal temperature of 71°C for all analyses. The least-squares means were determined using the PROC GLIMMIX procedure of SAS and were considered significant at P < 0.05.

Results: The trained sensory panel determined steaks from severe DC had greater (P < 0.05) tenderness ratings than those classified as mild DC and normal BCR colored loins. Dark-cutting loins classified as moderate had greater (P < 0.05) tenderness ratings than normal BCR colored loins and similar (P > 0.05) tenderness to both mild and severe DC loins. All DC classes had a less (P < 0.05) intense metallic flavor compared to normal BCR colored steaks. Consumer panelists found steaks from loins aged for 39 d had greater (P < 0.05) sustained juiciness in comparison to steaks from loins aged 21 d. Severe DC had greater (P < 0.05) sustained juiciness compared to mild DC and normal BCR colored steaks. Consumers noted that severe DC steaks had increased (P < 0.05) tenderness scores compared to mild DC and normal BCR colored steaks. No “off-flavors” were detected for any normal BCR colored or DC steaks by consumers.

Conclusion: In conclusion, DC beef holds promise for consumer sensory acceptance, and therefore potential value recovery is possible for DC beef products channeled to optimal foodservice markets. Understanding what consumers value and are willing to accept is vital to best marketing beef products.

Keywords: beef, consumer, dark-cutting, palatability, sensory

61 THE ASSOCIATION AMONG PORK QUALITY AND SENSORY TRAITS FOR THE PORK TENDERLOIN (PSOAS MAJOR)

Y. Wang^1,*, L. T. Vitanza¹, B. M. Bohrer¹, ¹Department of Animal Sciences, The Ohio State University, Columbus, Ohio, United States *bohrer.13@osu.edu

Objectives: The pork industry is actively searching for additional value for the loin primal. Establishing relationships among quality and sensory traits is important for the industry if advancements in consumer acceptance are to be prioritized, particularly for that of muscle cuts that have not been extensively studied. The objective of this study was to determine the associations between meat quality and sensory traits for the pork tenderloin (psoas major).

Materials and Methods: A total of 103 pork tenderloins (IMPS# 415) were purchased from a commercial supplier. Each sample was cut into 2 sections, one 10-cm section for quality analysis and one 5-cm section for sensory analysis. Quality analysis consisted of instrumental color (measured using a CM-600d colorimeter; Minolta Corp., Osaka, Japan), pH (measured using a portable MPI pH meter; Meat Probes Inc., Topeka, KS), cooking loss (cooked to an endpoint cooking temperature of 71°C), and Warner-Bratzler shear force. Sensory analysis consisted of juiciness, tenderness, flavor, and overall acceptability assessments using a trained sensory panel that utilized a 15-cm line scale where 0 was extremely dry, extremely tough, no flavor, or very unacceptable and 15 was extremely juicy, extremely tender, very flavorful, or very acceptable. Data were analyzed using PROC CORR of SAS v9.4 to generate Pearson correlation coefficients. In addition, data were categorized into 3 groups based on pH values [< 5.60 (low pH; n = 17); 5.60 to 5.80 (average pH; n = 70); > 5.80 (high pH; n = 16)] and 3 groups based on Warner-Bratzler shear force values [< 2.5 kg (tender; n = 25); 2.5 to 3.0 kg (intermediate; n = 48); > 3.0 kg (tough; n = 30)] and analyzed with PROC GLIMMIX of SAS with fixed effects of pH value group or Warner-Bratzler shear force group.

Results: Correlation coefficients suggested weak (r < |0.35|) and moderate (|0.36| ≤ r < |0.67|) associations between quality parameters and sensory characteristics. However, when samples were categorized into groups based on pH values and shear force values, interesting trends began to emerge. Low pH (< 5.60) tenderloins were lighter (P < 0.05) in color, had greater (P < 0.05) levels of cooking loss, tended to be perceived (P = 0.07) as less juicy by the sensory panel, were perceived (P < 0.05) as tougher by the sensory panel, and had lower levels of sensory acceptability compared with high pH (> 5.80) tenderloins. The average pH group (5.60 to 5.80) was intermediate in value when compared with low pH (< 5.60) and high pH (> 5.80) tenderloins with a linear effect (P < 0.05) for instrumental lightness, cooking loss, sensory juiciness, sensory tenderness, and sensory acceptability. Tender (< 2.5 kg force) tenderloins were perceived (P < 0.05) as more tender and more acceptable by the sensory panel compared with tough (> 3.0 kg force) tenderloins. Intermediate (2.5 to 3.0 kg force) tenderloins were intermediate in value compared with tender (< 2.5 kg force) and tough (> 3.0 kg force) tenderloins with a linear effect (P < 0.05) for sensory tenderness and sensory acceptability.

Conclusion: Overall, this study suggests that changes in important meat quality traits such as pH and instrumental tenderness are influential to sensory attributes for pork tenderloins. Future research efforts to quantify the underlying biological mechanisms of such quality traits will be beneficial for the pork industry.

Funding Source: Funding provided by the Ohio State University CFAES Internal Grants Program.

Keywords: color, physicochemical properties, pork quality, pork tenderloin, shear force

62 INFLUENCE OF SOUS-VIDE COOKING TIMES ON TEXTURE PROFILE ANALYSIS OF GROUND BEEF PATTIES

S. Shoup^1,*, J. Yancey¹, K. Vierck¹, ¹Animal Science, University of Arkansas, Fayetteville, Arkansas, United States *sshoup@uark.edu

Objectives: The objective of this study was to evaluate the impact of sous-vide cooking time on texture profile analysis of ground beef quality and palatability traits. The sous-vide method of cooking is a growing trend but has not been fully evaluated for meat quality. This method of cooking allows for the perfect degree of doneness by utilizing the long time, low temperature method. Meat is placed into a vacuum sealed bag and submerged in a hot water bath at a specific temperature for a certain amount of time depending on the desired degree of doneness. Therefore, we conducted this study to determine if the texture traits of ground beef was reduced.

Materials and Methods: Fresh 80:20 ground beef was obtained from a commercial vendor. Ground beef was finely ground through a 0.95 cm plate to create 10 batches, and immediately formed into 130 g patties using an automatic patty maker. Patties were assigned at random to one of 3 cooking times (n = 90 patties/cooking time): 2 h, 4 h, or 8 h. The patties were immediately placed into frozen storage at −20°C until further analysis occurred. Patties were thawed overnight in refrigeration before cooking. Patties from all time treatments were placed into a bain marie with water which was held at a temperature of 65.5°C. Samples were started in the sous-vide process at the same time and pulled after either 2 h, 4 h, or 8 h of cooking. The patties were then finished to 74°C on a clamshell grill. The temperature was measured at the geometric center of each patty. Texture profile differences were measured with a TA.XT plusC Texture Analyser, which quantifies hardness, adhesiveness, resilience, cohesion, springiness, gumminess, and chewiness. Data were analyzed as a single factor completely randomized design where time served as the main effect and batch served as the random effect. Peak temperature was used as a covariate. P values were considered significant when (P < 0.05).

Results: Time impacted all traits measured with the texture profile analyzer. Hardness is an indicator of the peak force used during the first compression cycle which corresponds to the first bite. Hardness was greater for both 4 h and 8 h compared to the 2 h cook time (P < 0.003). Cohesiveness is a ratio of the second peak force compression to the first. Cohesion was greater for 2 h than both 4 h and 8 h (P < 0.0001). Springiness is the height the sample recovers to after the first compression and before the second compression begins. Similar to cohesion, springiness was greater for 2 h than both 4 h and 8 h (P < 0.0001). Inversely, resilience was greater for the 2 h cook time compared to both 4 h and 8 h (P < 0.026). Gumminess comprises values from both hardness and cohesiveness, whereas chewiness is calculated from gumminess and springiness. Gumminess was greater for both 4 h and 8 h compared to 2 h (P < 0.006). Additionally, chewiness was greater for both 4 h and 8 h compared to 2 h (P < 0.0001). Lastly, adhesiveness at 4 h was less than that of 2 h and 8 h (P < 0.003).

Conclusion: These results indicate that cooking time does impact the texture profile analysis of sous-vide ground beef patties. For home use, determining ideal cooking time is crucial to ensure consumers are eating products that have the greatest possible quality. Further analysis should be conducted to determine appropriate cooking times to ensure meat quality is maintained.

Funding Source: This study was funded by the Arkansas Beef Council.

Keywords: beef, cooking duration, quality, sous vide, texture

63 THE IMPACT OF LIVER ABSCESS SEVERITY ON POSTMORTEM METABOLITES AND LEAN COLOR OF BEEF X DAIRY CATTLE

T. E. Schwartz^1,*, S. B. Smith¹, A. N. Arnold², J. W. Savell¹, K. B. Gehring¹, ¹Animal Science, ²Texas Veterinary Medical Diagnostic Laboratory, Texas A&M University, College Station, Texas, United States *tschwartz2@tamu.edu

Objectives: The objectives of this study were 1) to evaluate lean color differences in carcasses from beef × dairy (BxD) with liver abscesses and 2) to determine pre- and post-harvest metabolite differences between cattle with and without liver abscesses.

Materials and Methods: BxD steers (n = 201) were evaluated for the presence and severity of liver abscesses. Livers were scored using the Elanco Liver Scoring system: 1) MAJOR (A+), 2) MINOR (A−, A), and 3) NORMAL (0). A subset of carcasses (n = 30; 10 from each liver score category) were selected to determine the relationships among liver abscesses, lean color, and metabolites. Liver and pre-rigor M. sternomandibularis (Pre-Sterno) tissues were collected during harvest and frozen (−80°C). After carcass chilling, post-rigor M. sternomandibularis (Post-Sterno) was collected and frozen (−80°C). Instrumental color (L*, a*, b*) and pH were measured on the M. longissimus thoracis at the 12^th–13^th rib interface. Beef strip loins were collected, and 3 steaks (2.54 cm) were cut from each. Two steaks were packaged in PVC overwrap and evaluated over a 5-d display period for instrumental color (L*, a*, b*; hue, chroma, and ratios of deoxymyoglobin, oxymyoglobin, and metmyoglobin). One steak from each was frozen (−80°C) for subsequent analyses. Liver, Pre-Sterno, Post-Sterno, and loin tissue were evaluated for glucose-6-phosphate (G-6-P), glucose, glycogen, lactate, and citrate concentrations, and glycolytic potential values were calculated. Data were analyzed using the analysis of variance (ANOVA) function in JMP® Pro, Version 15.2.1 (SAS Institute Inc., Cary, NC).

Results: For the initial group of cattle (n = 201), liver abscesses were scored as MAJOR, 29.36%; MINOR, 14.43%; and NORMAL, 56.22%. For the chilled M. longissimus thoracis, there was no (P = 0.4374) difference in pH among liver score categories, and NORMAL possessed the highest in-plant a* values (P = 0.0211). For instrumental color over 5 d, MINOR had the highest L* values (P = 0.0035), MAJOR the highest a* (P = 0.0020) and chroma values (P < 0.0001), MAJOR and MINOR the highest b* values (P < 0.0001), and NORMAL the highest hue values (P < 0.0001). For loin steaks aggregated over the 5-d display period, MAJOR had the highest ratio of oxymyoglobin (P < 0.0001) and deoxymyoglobin (P = 0.0088), and NORMAL the highest metmyoglobin (P < 0.0001). NORMAL had the highest concentration of liver G-6-P (P = 0.0012), least liver glycogen (P = 0.0342), most Pre-Sterno glucose (P = 0.0188), and most loin G-6-P (P = 0.0026). MAJOR contained the most liver glucose (P = 0.0054) and loin citrate (P = 0.0436). MAJOR and MINOR had the most liver glycogen (P = 0.0342), leading to the highest liver glycolytic potential (P = 0.0245). Initial a* values revealed a redder color for NORMAL early postmortem, but metabolite differences influenced higher color stability for MAJOR and MINOR over 5 d.

Conclusion: This study indicates that there could be a relationship between liver abscesses and postmortem lean color. Differences in initial color and color stability over storage time, from carcasses with liver abscesses, is worth investigating. Changes in meat color via liver abscesses could negatively impact grading as well as consumer selection. Further research is needed to determine cause and effect of the metabolites evaluated and the role they play on color formation in cattle containing liver abscesses.

Funding Source: Funded in part by the Texas Cattle Feeders Association.

Keywords: glycolytic pathway, liver abscess, meat color, metabolites

64 THE RELATIONSHIP BETWEEN PH AND TEMPERATURE DECLINE WITH PORK QUALITY OF FIVE DIFFERENT MUSCLES

Y. Wang^1,*, M. Conte¹, L. G. Garcia¹, B. M. Bohrer¹, ¹Department of Animal Sciences, The Ohio State University, Columbus, Ohio, United States *bohrer.13@osu.edu

Objectives: The rate and extent of pH and temperature decline cause variation in pork quality traits, such as color and water-holding capacity. The relationship between early postmortem pH and quality of the pork loin (longissimus dorsi [LD]) has been studied. However, previous research indicates that quality traits of the LD were not representative of the entire carcass. Variation in pork quality among muscles exists due to the differences in their inherent biochemical profile and the events occurring during the postmortem period. Therefore, the objective of this study was to characterize the relationship between pH and temperature decline with color and water-holding capacity of 5 different pork muscles.

Materials and Methods: The pH and temperature of LD, psoas major (PM), semitendinosus (ST), triceps brachii (TB), and gluteus medius (GM) muscles from carcasses (n = 15) were measured during conventional chilling at 1, 3, 6, 9, 12, and 24 h postmortem. Instrumental CIE (L*, a*, b*) color values were evaluated using a Minolta CM-600d on the cut surface of each muscle. Drip loss of pork was assessed using 25-mm diameter cores with the EZ cup method over a 48-h period. The rate and the extent of pH and temperature decline, color, and drip loss were analyzed using a randomized complete block design in PROC GLIMMIX of SAS, with muscle as the fixed effect and pork carcass nested within slaughter event as a random effect. Stepwise regression analysis was performed with PROC REG of SAS to develop prediction equations for the parameters of interest while including slaughter event as dichotomous variables in the model.

Results: The main effect of muscle was significant (P < 0.05) for pH and temperature at each time point, as well as for color and drip loss. Pork LD, ST, and GM exhibited greater (P < 0.01) pH than TB and PM at 1 h postmortem, while PM, ST, and TB demonstrated greater (P < 0.01) pH than LD and GM at 24 h postmortem. Moreover, LD demonstrated the greatest (P < 0.01) rate of pH decline from 1 h to 3 h postmortem, while no differences (P > 0.05) in the rate of pH decline at other time points were observed between muscles. PM and ST had the lowest (P < 0.01) temperature at 1 h postmortem, while LD and PM had the lowest (P < 0.01) temperature at 24 h postmortem. Pork LD, ST, and GM demonstrated greater (P < 0.01) L* (lightness) than PM and TB. PM demonstrated the greatest (P < 0.01) a* (redness) among the 5 muscles. Moreover, LD had the greatest (P < 0.01) drip loss among the 5 muscles. Stepwise regression analysis was conducted using pH and temperature of individual muscle to predict color and drip loss. For LD, pH at 1 h postmortem explained greater variation (61%) in L* than pH at other time points. For ST, pH at 1 h postmortem explained greater variation in drip loss (50%) than pH at other time points. However, for the PM, TB, and GM, pH and temperature (when measured at each of the time points used in this study) explained less than 33% of the variation in color and drip loss.

Conclusion: The rate and extent of pH and temperature decline, color, and drip loss appear to be muscle-specific. Moreover, the relationship between pH and temperature decline with color and drip loss also appears to be muscle-specific. While both pH at 1 h and 24 h postmortem played critical roles in color and drip loss, pH at 1 h postmortem is the best predictor for the quality of LD but not for other muscles.

Funding Source: Funding provided by the Ohio State University CFAES Internal Grants Program.

Keywords: color, pH decline, temperature decline, water-holding capacity

65 EFFECT OF PRODUCT SIZE AND DOUBLE FREEZING CYCLES ON COLOR AND OXIDATIVE QUALITY OF DIFFERENT BEEF MUSCLES

A. Rivera^1,*, P. Dahunsi¹, J. Rodriguez¹, C. Taylor¹, T. Dobbins², M. Denzer³, P. Dias Morse⁴, K. Vierck⁴, J. Yancey⁴, J. Legako², D. Setyabrata^1,4, ¹Department of Animal Science, University of Arkansas, Fayetteville, Arkansas, United States, ²Department of Animal and Food Science, Texas Tech University, Lubbock, Texas, United States, ³Department of Food Science, University of Arkansas, Fayetteville, Arkansas, United States, ⁴Department of Animal Science, University of Arkansas System Division of Agriculture, Fayetteville, Arkansas, United States *aprivera@uark.edu

Objectives: Freezing is frequently used in the beef industry to extend the shelf-life of meat products. However, it can adversely affect quality, resulting in greater discoloration and lower oxidative stability. The degree of damage incurred is dependent upon the freezing rate, which is influenced by various factors, including product dimensions and freezer capability. Despite existing research exploring freezing effects using industrial technologies, there is limited understanding regarding the consequences of subsequent freezing utilizing consumer-grade freezers and meat products of different sizes. Thus, this study aims to assess the impacts of double freezing and muscle sizes on meat color and oxidative stability of beef muscles.

Materials and Methods: Paired beef muscles [M. longissimus lumborum (LL), M. gluteus medius (GM), and M. semitendinosus (ST)] from 15 USDA Low Choice beef carcasses were assigned into 2 sizes, section (SEC) or steak (STK), cut into 3 equal sections, and randomly assigned to one of the 3 freezer types, blast freezer (BLS), chest freezer (CST), or refrigerator freezer (FRI). Samples underwent the first freezing using a −20°C BLS, stored for 35 d, then thawed until the internal temperature reached 2°C. Afterward, samples were subjected to the second freezing using the assigned freezer types, stored for 35 d, and thawed using the aforementioned method. The SEC samples were cut into 2.54-cm steaks before analysis. All samples were subjected to pH, 5-d simulated color display in aerobic packaging (instrumental and visual), and lipid oxidation analyses. The experimental design of this study was a split-split design, where each animal carcass served as a block. Product size and refrigerator types were the fixed effects. All data were analyzed using PROC GLIMMIX of SAS, and least-squares means for all traits were separated at P < 0.05.

Results: Neither freezer types nor product size had an effect on the pH of LL and ST muscles (P > 0.05). However, product size and freezer type significantly impacted the final pH of GM, showing greater pH in SEC-BLS and lower in STK-CST compared to other treatments (P < 0.05). There was a significant size × day interaction, showing greater a* and lower Hue angle scores in SEC than in STK. The L*, b*, and chroma were greater in SEC samples compared to STK until day 3 of display (P < 0.05), regardless of muscle and freezer. Visual color analyses also demonstrated size × day interactions, reporting lower lean color score and higher discoloration in STK compared to SEC (P < 0.05) during display. The lipid oxidation levels significantly increased during display for all samples (P < 0.05). The SEC samples presented more oxidation when compared with STK in ST following display (P < 0.05). A significant size × freezer × day interaction was observed in LL, where all SEC samples and STK-FRI had significantly higher oxidation at day 5 compared to all other treatments.

Conclusion: Based on the results of this study, it could be suggested that product freezing size has a significant influence on meat color and oxidative stability. SEC samples displayed a more intense and better perceived red color, showing greater color stability and retarded discoloration compared to STK samples. Additionally, product freezing size impacted oxidative stability, showing that SEC presented lower oxidative stability than STK.

Funding Source: Research coordinated by the National Cattlemen’s Beef Association, a contractor to the Beef Checkoff.

Keywords: beef, color stability, consumer freezing, lipid oxidation, product size

66 IMPACT OF PRODUCT SIZE AND SUBSEQUENT CONSUMER FREEZING ON WATER-HOLDING CAPACITY, TENDERNESS, AND SENSORY ACCEPTABILITY OF DIFFERENT BEEF MUSCLES

P. O. Dahunsi^1,*, A. R. Pitti¹, S. Sebastian², M. Denzer³, P. Diaz-Morse⁴, K. R. Vierck⁴, J. Yancey⁴, J. F. Legako², D. Setyabrata^1,4, ¹Department of Animal Science, University of Arkansas, Fayetteville, Arkansas, United States, ²Department of Animal and Food Science, Texas Tech University, Lubbock, Texas, United States, ³Department of Food Science, ⁴Division of Agriculture Department of Animal Science, University of Arkansas, Fayetteville, Arkansas, United States *pdahunsi@uark.edu

Objectives: Despite its effectiveness in extending shelf life, freezing leads to quality deterioration, such as excessive moisture loss, rapid discoloration, and off-flavor development. Recently, there has been a rise in consumer demand for small single-served meat cuts. Alteration in product sizes could affect freezing rate and the quality of frozen meat quality, which may be worsened by multiple freeze-thaw cycles during storage. This study examined the quality impacts of different muscle sizes as well as double-freezing with different types of consumer freezers, which is currently unclear.

Materials and Methods: Paired strip loins (LL), top sirloin butts (GM), and eye of rounds (ST) were obtained at 3 d postmortem from 15 USDA Choice beef carcasses and aged until 28 d postmortem. The paired muscles were assigned into either steaks (STK) or sections (SEC). Each muscle was cut into 3 equal sections and randomly allotted to 3 freezer types [blast (BLS), chest (CST), refrigerator freezer (FRI)]. Sections assigned to STK were further cut into 2.54 cm steaks for the first freezing (size treatment). Samples were then stored frozen at −20°C for 35 d and thawed at 2°C. For the second freezing (freezer treatment), samples were stored frozen at the respective freezer type for another 35 d and re-thawed at 2°C. SEC samples were cut into steaks after thawing. Samples were then collected for drip loss, purge loss, cook loss, Warner-Bratzler shear force (WBSF), and consumer sensory analyses. Data were analyzed using the PROC GLIMMIX procedure of SAS. The least-squares mean for all traits were separated at P < 0.05. Carcass was the random effect, while size, freezer types, and their interaction were the fixed factor.

Results: Multiple main and interaction effects were observed for water-holding capacity from the different muscles. A size × freezer interaction was found only in GM, where STK-CST had the highest drip loss, and SEC-BLS had the lowest (P < 0.05). Drip loss was greater in STK compared to SEC in LL (P < 0.05) and was not impacted in ST (P > 0.05). For purge loss, SEC-BLS interaction had greater loss compared to other treatments in LL (P < 0.05). ST purge loss was impacted by both size and freezer effect, showing more loss in SEC and CST than in others (P < 0.05). Purge loss was not affected in GM (P > 0.05). A significant interaction in ST showed more cook loss in SEC-BLS than in other treatments. Cook loss was not affected in both LL and GM (P > 0.05). WBSF was only affected by size in LL and GM, showing greater tenderness in SEC compared to STK (P < 0.05). Lastly, consumer evaluation reported a lower tenderness score (P < 0.05) in SEC-FRI treatment in GM. Similarly, the same treatment received significantly lower tenderness acceptability and overall acceptability ratings from consumers. No difference in consumer evaluation was found in LL and ST, regardless of size and freezer types (P > 0.05).

Conclusion: The results suggest that although product size freezing may dictate the final WHC of frozen meat, the impact seems to vary with muscle type. However, both product size and freezer types only minimally impacted sensory quality in LL and ST, while SEC-FRI interaction significantly decreased the product’s acceptability in GM muscle. Further studies to identify volatile compound profiles are currently being conducted.

Funding Source: Research coordinated by the National Cattlemen’s Beef Association, a contractor to the Beef Checkoff.

Keywords: beef quality, consumer freezing, consumer sensory, double freezing, palatability

67 STRUCTURAL EQUATION MODELING FOR INVESTIGATING THE INFLUENCE OF DIET AND MUSCLE SOURCE ON COLOR STABILITY OF BEEF FROM NELLORE BULLS

A. P. Salim^1,*, L. C. S. Lima², M. S. Ferreira³, F. J. G. Vasconcellos³, C. A. Conte-Junior², T. Saldanha⁴, S. P. Suman¹, G. Rentfrow¹, S. B. Mano³, ¹Animal and Food Sciences, University of Kentucky, Lexington, Kentucky, United States, ²Chemistry Institute, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil, ³Department of Food Technology, Fluminense Federal University, Niteroi, ⁴Department of Food Technology, Federal Rural University of Rio de Janeiro, Rio de Janeiro, Brazil *apaulasalim@gmail.com

Objectives: The feeding system has been associated with differences in meat color, which is the main sensory attribute influencing purchase decisions at the point-of-sale. We hypothesized that muscle metabolism and color stability can be changed according to the feeding system. We aimed to evaluate the influence of diet (grain-fed and pasture-raised) and muscle (longissimus lumborum and psoas major) on color stability of beef from Nellore bulls employing structural equation modeling (SEM).

Materials and Methods: Longissimus lumborum (LL) and psoas major (PM) muscles were obtained from the carcasses of ten (n = 10) grain-fed and ten (n = 10) pasture-raised Nellore bulls. The animals were slaughtered under Brazilian Federal Inspection. LL and PM muscles were excised from the right side of each carcass at 24 h postmortem, vacuum packed and aged (2°C) for 60 d. The aged samples were fabricated into 2.5-cm-thick steaks individually packaged on polystyrene trays, over-wrapped with oxygen-permeable polyvinyl chloride film, and stored for 9 d at 4°C. Analysis of instrumental color and metmyoglobin reducing activity (MRA) was performed on days 0, 6, and 9. Instrumental lightness (L*), redness (a*), and yellowness (b*) were evaluated using a portable spectrophotometer CM-600D (Konica Minolta Sensing Inc., Osaka, Japan) with illuminant A, 8 mm aperture, and 10° standard observer. The ratio of reflectance at 630 nm and 580 nm (R630/580) was evaluated to indirectly estimate color stability of LL and PM. The SEM was used to examine the influence of muscle (LL and PM), diet (grain and pasture), and days of refrigerated storage (0, 5, and 9) on beef color (L*, a*, b*, and R630/580), and MRA. The Scanning Electron Microscopy analysis was performed using the R software (version 4.2.2; R Core Team 2022) with lavaan package (version 0.6-12; Rosseel 2012) and sem function. The estimation and optimization method were the Maximum Likelihood (ML) and the Nonlinear Minimization, which were subjected to Box Constraints (nlminb). Two conceptual models of structural equations were performed considering a) diet (grain and pasture) separately, and a combined effect of muscle (LL and PM), to evaluate which feeding strategy promotes better color and oxidative stability; and b) muscle (LL and PM) separately, and a combined effect of diet (grain and pasture) to evaluate the color stability of each muscle. To evaluate and compare the models, the model-fit criteria were the comparative fit index (CFI), Tucker-Lewis index (TLI), Standardized Root Mean Square Residual (SRMR), Root Mean Square Error of Approximation (RMSEA), and modification indices. A linear relationship between the variables was assumed, as follows: Y = α + γx + ɛ where Y = endogenous variable; α = intercept; γ = path from the exogenous to the endogenous variables; x = exogenous variable; and ɛ is the residual of Y.

Results: Muscles (LL and PM) from grain-fed animals were positively related to redness (a* value; γ = 1.020), yellowness (b* value; γ = 0.708), color stability (R630/580; γ = 1.006), and MRA (γ = 0.674). Muscles from pasture-raised animals were positively related to lightness (L* value; γ = 0.700), redness (a* value; γ = 0.901), yellowness (b* value; γ = 0.980), and color stability (R630/580; γ = 0.604), but negatively related to MRA (γ = −0.380). LL and PM muscles from pasture-raised bulls may exhibit lower oxidative stability compared to their grain-fed counterparts based on MRA results.

Conclusion: The results indicated that diet plays an important role in the color stability of fresh beef and contributed to muscle-specific variations in color of beef from Nellore cattle. The negative relationship of MRA and the muscles (LL and PM) from pasture-fed bulls suggests a potential shift in muscle metabolism from glycolytic to oxidative due to pasture feeding. Dietary strategies may be utilized to improve the color stability of fresh beef muscles from Nellore cattle.

Keywords: structural equation modeling, Nellore, fresh meat color, diet, muscle source

68 RED CLOVER SUPPLEMENTATION DOES NOT INFLUENCE THE COLOR STABILITY OF LAMB LONGISSIMUS LUMBORUM MUSCLES

K. Mondal¹, M. E. Ragsdale¹, G. Rentfrow¹, D. G. Ely¹, B. E. Davis², J. Weinert-Nelson², M. D. Flythe², Y. Wang³, A. P. Salim^1,*, S. P. Suman¹, ¹Animal & Food Sciences, University of Kentucky, Lexington, Kentucky, United States, ²Forage Animal Production Research Unit, USDA-ARS, Lexington, Kentucky, United States, ³Department of Animal Sciences, Ohio State University, Columbus, Ohio, United States *apaulasalim@gmail.com

Objectives: Red clover is a perennial legume mostly used in lamb diet to improve feed efficiency and growth. The benefits in animal performance are due to the ability of red clover to enhance protein degradability and lipolysis in the gastrointestinal tract. Despite the benefits for animal performance, the influence of red clover in lamb color is not completely understood. We aimed to investigate the effect of red clover supplementation on the color stability of longissimus lumborum (LL) muscles from ram lambs during refrigerated storage.

Materials and Methods: All protocols were approved by the Institutional Animal Care and Use Committee of the University of Kentucky (Protocol #2021-3968). Twenty-four Polypay ram lambs were utilized for this experiment. The lambs (initial age: 98.12 ± 1.71 d; initial weight: 32.55 ± 0.64 kg) were blocked by sire and initial body weight, and randomly assigned to one of 4 experimental diets: orchardgrass (Dactylis glomerata L.) without red clover (Trifolium pratense L.) hay (CON; n = 6); 2.5% red clover diet with orchardgrass hay (2.5-RC; n = 6); 5% red clover diet with orchardgrass hay (5-RC; n = 6); and 7.5% red clover diet with orchardgrass hay (7.5-RC; n = 6). The lambs were fed ad libitum until reaching the target slaughter weight of 59 kg, and then harvested under USDA inspection. After 24 h postmortem, the LL muscles from both sides of the carcasses were excised and fabricated into 2.5-cm-thick chops. The chops were packaged in aerobic conditions, and randomly assigned to 0, 3, and 6 d of storage (2°C), in the darkness. Instrumental color (L*, a*, and b*), color stability (R630/580), metmyoglobin reducing activity (MRA), and total color change (ΔE) were assessed. The experimental design was a split-plot design, with the red clover diet as the whole plot and display days as the sub-plot treatments. The experimental units were the LL muscles obtained from each lamb carcass. The chops were designated as sub-plot experimental units. The analysis of variance was assessed using the PROC GLIMMIX procedure of SAS version 9.4 (SAS Institute Inc., Cary, NC). The Least-squares means were separated using the PDIFF option with a Tukey-Kramer adjustment, and the differences among means were considered statistically different at a 5% level.

Results: No effect of diet (P > 0.05) was observed in surface lightness, redness, yellowness, color stability (R630/580), and MRA. Surface redness and color stability (R630/580) decreased (P < 0.05) from day 0 to 6 of storage, whereas an increase (P < 0.05) of yellowness was observed in all samples. MRA exhibited an increase (P < 0.05) from day 3 to 6. The LL chops from lambs fed with red clover (2.5-RC, 5-RC, and 7.5-RC) exhibited lower (P < 0.05) total color change (ΔE) than their control counterparts.

Conclusion: These findings suggested that red clover supplementation can be explored as a promising feeding strategy without compromising fresh lamb color.

Keywords: lamb color, loin, oxidative stability, Trifolium pratense

69 INFLUENCE OF FAT SOURCES AND LEVELS OF VITAMIN E ISOFORMS IN BACON QUALITY FROM HEAVY SLAUGHTER WEIGHT (150 KG) PIGS

M. Kelley¹, D. Wang¹, G. Rentfrow¹, M. Lindemann¹, A. P. Salim^1,*, S. P. Suman¹, ¹Animal & Food Sciences, University of Kentucky, Lexington, Kentucky, United States *apaulasalim@gmail.com

Objectives: Due to the rising cost of feed ingredients, producers are utilizing alternative feedstuffs, such as fat source and dried distillers’ grains with solubles (DDGS). The swine industry has responded to these challenges by developing leaner genotype pigs by supplementing swine diets with unsaturated fat sources, which lead to an increase in polyunsaturated fatty acids in pork. However, the increase of unsaturated fatty acids is associated with lipid oxidation and poor belly quality. Dietary inclusion of vitamin E has been reported to decrease lipid oxidation in pork. In this perspective, the aim of this study was to evaluate the effect of fat (cornstarch, tallow, corn oil, and coconut oil) addition and vitamin E supplementation (11 and 200 IU/kg) on bacon quality from heavy slaughter weight (150 kg) pigs.

Materials and Methods: A total of 64 individually fed pigs were blocked by body weight and sex, and randomly assigned to one of the 8 dietary treatments in a 4 × 2 factorial arrangement. Fat treatments included cornstarch (CS), tallow (TW), corn oil (CO), and coconut oil (CN). Vitamin E (VE) supplementation was at 11 IU/kg and 200 IU/kg. Pigs were humanely slaughtered at ∼150 kg live weight at the University of Kentucky Meat Lab under USDA inspection, under the protocols approved by the Institutional Animal Care and Use Committee of the University of Kentucky. The bellies (IMPS # 408) were removed, weighed individually, and divided into 6 sections for bacon processing. Evaluation of belly depth, belly flex, and belly angle were performed. Data analysis was performed in SAS by least-squares analysis of variance using the generalized linear model (GLM) as a randomized complete block design. The individual pig served as the experimental unit. Statistical differences were established at P ≤ 0.05, whereas tendencies were established at P ≤ 0.10.

Results: Belly depth and belly flex were significantly affected by dietary fat sources (P < 0.01) but not by dietary VE supplementation (P > 0.01). Pigs fed CO diet had the lowest lateral distance (P < 0.01), greatest vertical distance (P < 0.01), and smallest belly angle (P < 0.01), making it the softest belly. Pigs fed CN had the greatest lateral distance (P < 0.01), lowest vertical distance (P < 0.01), and largest belly angle (P < 0.01) compared to the other groups, making it the firmest belly.

Conclusion: The findings demonstrated the importance of dietary fat sources on belly and bacon quality from heavy slaughter weight (150 kg) pigs. Dietary fat sources with more saturated fatty acids could improve the belly firmness and the quality of bacon compared to the fat sources with greater polyunsaturated fatty acids.

Keywords: bacon quality, heavy pigs, pork belly, vitamin E

70 FRESH PORK COLOR OF HEAVY SLAUGHTER WEIGHT (150 KG) PIGS FED DIFFERENT FAT SOURCES AND LEVELS OF VITAMIN E ISOFORMS

M. Kelley¹, D. Wang¹, G. Rentfrow¹, M. Lindemann¹, A. P. Salim^1,*, S. P. Suman¹, ¹Animal & Food Sciences, University of Kentucky, Lexington, Kentucky, United States *apaulasalim@gmail.com

Objectives: The increasing demand for pork can only be met by increasing the slaughter weight and exploring alternative feed ingredients. Vitamin E (VE) is an antioxidant that contributes to improving the oxidative stability of pork. However, the interactions between VE isoforms, fat sources, and pork quality are rarely reported. The objective of this study was to evaluate the effect of supplementing alpha-tocopheryl-acetate (ATA) and gamma-tocopherol (GT) VE isoforms with corn oil (CO) and tallow (TW) on color of fresh pork from heavy weight (>150 kg) pigs.

Materials and Methods: The experiment was conducted under protocols approved by the Institutional Animal Care and Use Committee of the University of Kentucky. A total of 72 individually fed pigs (n = 72) were blocked by sire, body weight, and sex, and then randomly assigned to individual pens. Vitamin E treatments included 4 levels of ATA (11, 40, 100 and 200 ppm) and 2 levels of mixed tocopherols, primarily GT (40 and 100 ppm). Pigs were humanely slaughtered at approximately 150 kg live weight at the University of Kentucky’s USDA-inspected Meat Laboratory. After 24 h postmortem, a 2.54-cm chop was removed from the longissimus thoracis, placed on foam trays and overwrapped in polyvinyl chloride (PVC) film to perform analysis of instrumental color. Lightness (L*), redness (a*), yellowness (b*), hue angle (H*), and chroma (C*) values were measured from 3 random locations on the light-exposed surfaces, using a HunterLab MiniScan XE colorimeter (HunterLab Associates, Reston, VA) with a 2.54 cm diameter aperture, illuminant A, and 10° standard observer, on days 1, 3, 5, and 7 of retail display (1300 Lux). Data analysis was performed in SAS by least-squares analysis of variance using the generalized linear model (GLM) as a randomized complete block design. The individual pigs served as the experimental units. Statistical differences were established at P ≤ 0.05, and tendencies were established at P ≤ 0.10.

Results: In general, the chops from pigs fed GT supplementation tended to have a greater L* value (P ≤ 0.10) during shelf life than their counterparts fed same levels of ATA. The TW supplemented pigs tended to have a greater L* (P ≤ 0.10) by the end of retail display. Feeding GT at 40 ppm resulted in a greater (P < 0.05) L* and hue, and lower (P <0.05) a* and chroma (paler less red color), compared to 40 ppm ATA. In contrast, feeding GT at 100 ppm resulted in a lower (P < 0.05) L* and hue, and greater (P < 0.05) a* and chroma (darker redder color) for the first 7 d of retail display, than 100 ppm ATA. The chops from pigs fed TW displayed greater (P < 0.05) L* and b* values for extended retail display compared to the pigs fed CO.

Conclusion: The findings demonstrated that feeding 40 ppm of GT decreased redness and increased lightness, whereas feeding 100 ppm of GT resulted in darker appearance for the first 7 d of retail display, compared to ATA supplementation. The use of GT with TW can be exploited as a pre-harvest strategy to increase the color stability of fresh pork from heavy pigs during retail display.

Keywords: alpha-tocopheryl-acetate, fat source, fresh pork color, gamma-tocopherol

71 EFFECTS OF THE DIETARY CONCENTRATE LEVEL ON CARCASS CUTABILITY TRAITS AND CUTOUT PERCENTAGES OF BOER AND KIKO WETHERS AND DOELINGS

K. Hearn^1,*, I. T. Luna², R. Puchala², D. Tadesse², H. Yirga², A. Patra², A. Sonibare², M. Pfeiffer¹, R. Ramanathan¹, A. L. Goetsch², G. G. Mafi¹, ¹Animal and Food Sciences, Oklahoma State University, Stillwater, Oklahoma, United States, ²American Institute for Goat Research, Langston University, Langston, Oklahoma, United States *grace.harris@okstate.com

Objectives: The number of meat goats produced in the United States has steadily increased since 1987 and saw a major increase from 415,196 to 2,622,000 in 2019 (USDA NASS). Additionally, Boer goats have been used in the US to improve carcass composition in purebred and crossbreeding systems (Casey & Van Niekerk, 1988). However, limited knowledge is available on the effects of diet on meat carcass traits. Thus, the objective of the study was to determine the effects of dietary concentrate level on carcass traits of Boer and Kiko wethers and doelings.

Materials and Methods: At approximately 4 mo of age, 72 kids: 36 Boer (18 wethers and 18 doelings) and 36 Kiko (18 wethers and 18 doelings) goats were weaned and randomly assigned to one of the 3 feeding programs. The concentrate ingredients included a mixture of wheat middlings, rolled oats, corn and soybean meal, with the forage portion being Lespedeza hay. The concentrate diet treatments included 30% (30C-27) fed to 27.2 kg, 30% fed to 36.3 kg (30C-36), and 30% fed to 27.2 kg then transitioned to 70% (70C) concentrate until 36.3 kg. Other than concentrate percentages, all other feed ingredients were the same to minimize subsequent variation in diets and fed for ad libitum consumption. Goats were harvested following typical commercial procedures at approximately 8 (30C-27) and 10 (30C-36 and 70C) mo of age. All carcass data were collected following the Meat Goat Selection, Carcass Evaluation and Fabrication Guide from Louisiana State University. Fabrication into the major wholesale cuts (IMPS 11 series) occurred 48 h postmortem and all weights recorded to ensure 99% to 100% recovery of cold carcass side weight (only left sides of carcasses).

Results: Overall, wethers had heavier (kg) hot and cold carcass weights and were heavier muscled (P < 0.05) than the doelings regardless of diet or breed. Boer goats had heavier carcass weights, were heavier muscled with higher confirmation scores, larger leg circumferences (cm) and higher leg scores than the Kiko goats. Kiko goats had more internal fat (P < 0.05) than the Boer goats. Moreover, doelings presented more (P < 0.05) internal fat (%) than wethers. Goats fed the 70C diet had the heaviest (P < 0.05) hot carcass and cold carcass weights (kg), the heaviest leg, loin, rack, shoulder, and rib weight, as well as the largest leg circumference compared to the other feeding treatments regardless of breed or sex. Furthermore, the goats fed the 70C diet had more (P < 0.05) overall fat cover with more body wall fat and kidney/pelvic fat (%) than the goats fed either the 30C-27 or 30C-36 diet. In conclusion, Boer goats were larger and heavier muscled (P < 0.05) than the Kiko goats, and the wethers were larger and heavier muscled (P < 0.05) than the doelings, while the Kiko goats and doelings had more (P < 0.05) internal fat. Finally, the Boer goats fed the 70C diet were the most market ready based on weight, fat cover, and muscling.

Conclusion: Therefore, feeding increased concentrate diet should be considered by producers.

Funding Source: American Institute for Goat Research

Keywords: carcass, cutability, goat

72 AGING INFLUENCES COLOR AND OXIDATIVE STABILITY OF BEEF BICEPS FEMORIS MUSCLE

A. P. Salim^1,*, G. Rentfrow¹, Y. Wang², M. Nair³, S. P. Suman¹, ¹Animal & Food Sciences, University of Kentucky, Lexington, Kentucky, ²Department of Animal Sciences, Ohio State University, Columbus, Ohio, ³Department of Animal Sciences, Colorado State University, Fort Collins, Colorado, United States *apaulasalim@gmail.com

Objectives: Wet aging of postmortem skeletal muscles has been extensively utilized to enhance beef tenderness. On the other hand, prolonged aging could adversely affect beef color. Biceps femoris (BF) is a glycolytic muscle less susceptible to aging-induced discoloration. The impact of wet aging on the color stability of beef BF is not completely understood. Therefore, the aim of the present study was to examine the effect of postmortem wet aging (for 0, 7, 14, and 21 d) on color stability of beef BF muscles.

Materials and Methods: The BF muscles (IMPS #171B) were excised (24 h postmortem) from both sides of eight (n = 8) beef carcasses (USDA Select grade) obtained from the USDA-inspected meat laboratory of the University of Kentucky. The muscles were further divided into 2 equal-length sections, vacuum-packaged, and randomly assigned to aging at 2°C for either 0, 7, 14, or 21 d. During each aging period, muscle sections were fabricated into 2.5-cm thick steaks, individually over-wrapped, and allocated to refrigerated storage for 0, 3, or 6 d. Instrumental lightness (L*), redness (a*), yellowness (b*), hue, chroma, and R630/580 were evaluated on each day of storage. The experimental design was a randomized complete block design, where each carcass served as a block. The main effects of muscle source and aging days and their interactions were analyzed using the Mixed Procedure of SAS. The least-squares means for protected F-tests (P < 0.05) were separated by using least significant differences and were considered significant at P < 0.05.

Results: BF steaks from 14 and 21 d aging exhibited greater (P < 0.001) L* values on day 0 of storage, whereas non-aged steaks (0 day) exhibited greater (P < 0.001) lightness on day 6 of storage. During storage, non-aged steaks exhibited an increase (P < 0.05) in lightness, while BF steaks from 14 and 21 d aging demonstrated a decrease (P < 0.05) in L* values from day 0 to 6. Aged BF samples (7, 14, and 21 d) exhibited greater (P < 0.05) a* values than their non-aged counterparts on storage days 0 and 3. Nevertheless, a* values decreased (P < 0.05) in all samples during storage. On days 0 and 3 of storage, aged BF steaks exhibited greater (P < 0.05) b* values compared to their non-aged counterparts. Aged BF steaks demonstrated a decrease (P < 0.05) in yellowness, whereas their non-aged counterparts exhibited no changes (P > 0.05) in b* values during 6 d of storage. Aging did not affect (P > 0.05) hue angle. During storage, an increase (P < 0.05) in hue angle was observed in all BF samples from day 0 to 6. Aged BF steaks exhibited greater (P < 0.05) chroma compared to their non-aged counterparts on storage days 0 and 3, whereas on day 6, aged and non-aged samples exhibited similar (P > 0.05) chroma. All BF steaks exhibited a decrease (P < 0.05) in chroma from day 0 to 6 of storage. Non-aged and aged samples exhibited overall similar (P > 0.05) color stability (R630/580) on days 0, 3, and 6, whereas on day 3, aged steaks exhibited greater (P < 0.05) color stability than thein non-aged counterparts.

Conclusion: These findings suggested that wet aging influenced the color stability of beef BF muscle by improving surface redness and color stability. Wet aging may be a practical processing strategy in the retail beef industry to improve the color stability of BF steaks.

Funding Source: This work is supported by the National Institute of Food and Agriculture, U.S. Department of Agriculture, Hatch-Multistate Project 7003954.

Keywords: color stability, meat color, muscle specificity

73 ESTABLISHING FREEZING AND THAWING FABRICATION TECHNIQUES AND GUIDELINES FOR FOODSERVICE

J. E. Edwards^1,*, K. M. Harr¹, M. Denzer¹, M. Pfeiffer¹, G. G. Mafi¹, R. Ramanathan¹, ¹Animal and Food Science, Oklahoma State University, Stillwater, Oklahoma, United States *jade.edwards@okstate.edu

Objectives: Numerous events occurred as a result of the COVID-19 pandemic, which forced the meat industry to implement new practices and shift products from foodservice to retail. The closure of foodservice establishments left many large, packaged products with no destination, thus resulting in more frozen beef. Minimal research has been conducted investigating the impact of frozen versus thawed fabrication of loins. Therefore, the objective of this study was to establish freezing and thawing techniques and guidelines for beef longissimus steaks for foodservice.

Materials and Methods: USDA Choice paired beef strip loins (n = 22) were obtained from a commercial beef processing facility. Strip loins were weighed in the package and then wet-aged for 21 d at 4°C. Following aging, loins were frozen for 14 d at −21°C to indicate the first freezing cycle. Loins were then designated to be fabricated in a frozen or thawed state. Loins designated to be thawed were held at 4°C for 7 d while loins designated to the frozen treatment remained at −21°C for 7 d until fabrication. Loins were reweighed, and 2.54 cm steaks were cut beginning with the anterior end of each loin. Steaks were then weighed, individually vacuum packaged, and designated to one of 3 freezing storage temperatures, −12°C, −18°C, or −21°C, and frozen for 6 mo. Steaks within each frozen storage temperature were assigned to one of 3 tests: consumer sensory, trained sensory, or Warner-Bratzler shear force (WBSF). Steaks designated for trained sensory panel were also used to determine trained internal color ratings and instrumental cooked color using a HunterLab MiniScan spectrophotometer. Steaks assigned to WBSF were also used to determine lipid oxidation. Steaks from all 3 tests were used to determine steak thaw and cook loss. The GLIMMIX Procedure of SAS was used to determine the least-squares means. Least-squares means with a P < 0.05 were considered significant.

Results: Consumer panel results showed no differences (P > 0.05) for tenderness, juiciness, flavor liking, overall liking, and off-flavor detection for both fabrication state and storage temperature. Correspondingly, trained sensory panels found no differences (P > 0.05) in initial juiciness, sustained juiciness, tenderness, connective tissue amount, off-flavor, or beef flavor. Furthermore, trained sensory panel results indicated no differences (P > 0.05) in internal cooked color ratings. Additionally, there were no differences (P > 0.05) in instrumental L*, a*, b*, chroma, or hue values for internal cooked color. Steaks thawed for fabrication had lower (P < 0.05) WBSF values than frozen fabricated steaks. Loins and steaks from loins designated to thawing before fabrication had a greater (P < 0.05) percentage of thaw loss when compared to loins and steaks from loins assigned to frozen fabrication. No differences were noted (P > 0.05) in steak cook loss regardless of fabrication state or freezing storage temperature. In addition, there were no (P > 0.05) differences in lipid oxidation values between treatments.

Conclusion: By fabricating steaks in a frozen state before long-term storage, product yield is increased without significantly affecting palatability; therefore, products destined for foodservice could be fabricated frozen.

Funding Source: This research was coordinated by the National Cattlemen’s Beef Association, a contractor to the Beef Checkoff.

Keywords: beef, fabrication, foodservice, freezing, palatability

74 VITAMIN C SUPPLEMENTATION PRIOR TO TRANSPORTATION AFFECTS ANTEMORTEM AND POSTMORTEM OXIDATIVE PRODUCTS IN COMPOSITE CALVES

S. N. Barker^1,*, P. R. Broadway², N. C. Burdick Sanchez², J. F. Legako¹, C. L. Bratcher³, ¹Animal and Food Sciences, Texas Tech University, ²ARS-LIRU, USDA, Lubbock, Texas, United States, ³Animal and Dairy Sciences, Mississippi State University, Starkville, Mississippi, United States *sam.barker@ttu.edu

Objectives: The objective of this study was to evaluate the effect of supplementation prior to transportation on antemortem and postmortem oxidative measures in calves exposed to transport stress.

Materials and Methods: Composite calves (n = 40; 110 kg body weight [BW] ± 10.95) were randomly assigned to one of 4 treatment groups on d −4: Non-transported negative control (Neg), Positive control (Pos) transported for 4 h, Oral amino acid drench (Drench; DuoPort; Omni Animal Health) administered −1 h before transportation for 4 h, and Vitamin C injection (Vit C; administered i.m. 14.1 mg/kg BW) administered −1 h before transportation for 4 h. Calves were fitted with indwelling jugular catheters on d −1. Plasma was isolated from whole blood at −12, −1, 0, 1, 2, 4, and 6 h, and immediately prior to harvest relative to transportation. Calves were randomly assigned across treatment groups to a trailer location (front, middle, or back) and level (top or bottom) within a commercial potbelly cattle trailer. Transportation began at 0 h and continued for 4 h, with stops for blood collection every hour. Plasma was analyzed for indicators of oxidative stress and ascorbic acid concentrations. Calves were humanely euthanized after 6 h post-challenge, and the Longissimus dorsi (LD) was immediately collected, vacuum packaged, and stored under refrigeration until 7 d postmortem. After 7 d, steaks from the LD were fabricated into 2.54 cm thick steaks and allocated to retail display of 0, 3, 6, or 9 d. Steaks displayed 9 d were evaluated for instrumental and trained color every 12 h. All steaks were analyzed for malondialdehyde (MDA) concentrations following their assigned aging. Time, treatment, and their interactions, as well as change from baseline values in antemortem measures, were analyzed with calf as a repeated measure using the GLIMMIX procedure of SAS.

Results: Reactive oxygen species (ROS) were greatest in Vit C calves through the antemortem challenge period (P < 0.05), except at 4 h where all other treatment groups were greater (P < 0.05). Antemortem MDA concentrations changed the least in Vit C calves (P < 0.05). Total antioxidant capacity was also the lowest in Vit C calves throughout the antemortem period (P < 0.05). In the postmortem evaluation, Vit C calves had the lowest L* values of all treatment groups during display (P < 0.001), where all other treatment groups were similar (P > 0.05). Vitamin C steaks also exhibited MDA concentrations approximately 6 times greater than any other treatment group (P < 0.05), although MDA values increased for all treatments as days of display increased (P < 0.05).

Conclusion: Prior work has indicated that usage of vitamin C prior to transport may reduce oxidative stress and improve growth performance. Nonetheless, the current data argue that vitamin C may, instead, be detrimental to the final meat quality and lack efficacy when used as a supplement prior to transport to prevent oxidative stress in vivo and postmortem. These data further indicate an oxidizing effect of vitamin C on postmortem meat quality, contributing to increased lipid oxidation during display.

Funding Source: National Bio- and Agro-Defense Facility National Laboratorian Training Program (NBAF-NLTP) at Texas Tech University

Keywords: lipid oxidation, oxidative stress, retail display

75 RNASEQ ANALYSIS OF SKELETAL MUSCLE FROM DARK CUTTING CARCASSES

Z. Kwiatkowski^1,*, D. Hagen¹, P. Riggs², ¹Department of Animal Science, Oklahoma State University, Stillwater, Oklahoma, ²Department of Animal Science, Texas A&M University, College Station, Texas, United States *Kwiatkowskizak@gmail.com

Objectives: Dark cutting in beef cattle can result from the onset of stressors prior to slaughter that depletes glycogen stores, resulting in increased postmortem pH levels and dark, firm and dry (DFD) meat composition. Meat quality of DFD beef is reduced and contributes to economic loss for the beef industry. While the endpoint biochemistry that results in carcasses that grade as “dark cutters” is well established, the genetic mechanisms that may trigger the response remain unclear. In this project, our objective was to identify key genes or genetic pathways that are associated with the DFD phenotype and may be activated as part of a stress response that leads to the defect.

Materials and Methods: Short-read Illumina RNA sequencing was conducted on mRNA extracted from Longissimus thoracis biopsies obtained from 78 Angus-Nellore steers immediately after harvest. Of this contemporary group, 25 carcasses graded as dark cutters (DC), 8 of which were more severely affected (SDC), and 53 with normal meat quality (Control). Bioinformatic analysis of read counts was conducted using EdgeR software in RStudio to identify differentially expressed genes (DEG) between the groups.

Results: Principal component analysis (PCA) did not show distinct clustering of each of these groups, suggesting that each group had high variation among individuals. From EdgeR analysis, 614 DEG (FDR < 0.05) were identified from all 3 groups together. Differential gene expression between each of the groups was identified following pairwise comparison among 3 groups. Seventy-nine DEG were identified between control and DC samples, Control versus SDC comparison resulted in 569 DEG, and DC versus SDC groups identified 4 DEG. The results of pairwise comparisons show significant differences between Control and SDC groups in expression profiles, but very little between DC and HDC groups suggesting similar gene activation but different levels of expression between these 2 groups. Following Weighted Gene Correlation Network Analysis (WGCNA), 81 gene network modules each containing a set gene list of similar expression profiles. Of these, 8 modules were found positively correlating with the DFD phenotype. Enrichment analysis within Database for Annotation, Visualization and Integrated Discovery (DAVID) software was utilized to identify various pathways given each gene list from the DEG generated and the modules from WGCNA. Two possible pathways were identified within the Control versus SDC DEG for circadian rhythm and AMPK signaling pathway (FDR < 0.05). AMP-activated protein kinase (AMPK) is known to activate in response to stress and could be a potential target pathway for dark cutting. One pathway of interest from WGCNA included spliceosome activity and pathways differentially expressed with the greatest statistical significance (FDR < 0.05).

Conclusion: The key-player genes identified may contribute to the DFD phenotype within these pathways in response to various environmental influences and stressors.

Funding Source: This research was supported by Oklahoma State University graduate college in the Department of Animal Science.

Keywords: beef cattle, dark cutting, dark, firm and dry, mRNA, RNA sequencing

76 EFFECTS OF FREEZING AND DISPLAY CASE TYPE ON INSTRUMENTAL COLOR, MOISTURE LOSS, AND SHEAR FORCE IN PORK LOIN CHOPS

V. Yancey^1,*, P. Dahunsi², J. Yancey², E. Yancey³, K. Vierck², D. Setyabrata^2,4, ¹FFA, Huntsville High School, Huntsville, Arkansas, United States, ²Animal Science, University of Arkansas System Division of Agriculture, Fayetteville, Arkansas, United States, ³Research, Tyson Foods, Springdale, Arkansas, United States, ⁴Animal Science, University of Arkansas, Fayetteville, Arkansas, United States *jws09@uark.edu

Objectives: Freezing is a common method for preserving pork and ensuring a steady supply in the market. However, freezing often resulted in quality defects, such as rapid discoloration and high moisture loss following thawing. The extent of these defects is observed during retail market display and could be exacerbated during the process. Temperature fluctuation has been reported in commonly used open-front retail cases, which can lead to further reduction of color stability in the meat during display. Recently, retailers have shown increased interest in close-door retail cases due to their ability to maintain temperature and improve energy efficiency. The objective of this study was to determine the impact of freezing and retail display case type combination on color, moisture loss, and shear force of pork loins during retail display.

Materials and Methods: Center-cut pork loins (n = 6) were purchased from a local big-box store with a similar box date. At 14 d post box date, loins were halved and assigned to fresh or frozen treatments. Fresh halves were processed immediately, and frozen sections were vacuum packaged, frozen at −20°C for 16 d, and thawed in a 4°C water bath overnight. During processing, a chop was removed from each half for pH and drip loss measurement. Halves were then cut into 2.54-cm chops, and chops were randomly assigned to case treatments (closed-door or open-front), packed in foam trays with PVC overwrap, and displayed in assigned cases under continuous LED lighting for 7 d. Color (L*, a*, b*, hue angle, and chroma) was measured on 2 chops using a MiniScan EZ spectrophotometer. At d 4 of display, 2 chops from each half in each treatment were removed, cooked to 71°C on clam-shell grills, and measured for Warner-Bratzler shear force (WBSF). Chops were weighed prior to and after display and cooking to determine display loss and cook loss. Data were analyzed in a balanced complete block design with a split-plot arrangement and display day as a repeated measure for color measurement using the PROC GLIMMIX procedure of SAS.

Results: Freezing did not affect (P > 0.05) pH and drip loss. Both freezing and case effects impacted display loss, indicating more loss in frozen treatment compared to fresh (P < 0.05) and a higher loss in open-front compared to closed-door case (P < 0.05). Cook loss was not significantly impacted, regardless of freezing and case treatments. An interaction of freezing × display day showed that frozen chops had higher and more rapid hue angles increase (P < 0.05) than fresh chops. The same significant interaction was also observed in L*; however, the difference was numerically impractical. Chops from previously frozen halves were more yellow (P < 0.05) and had great chroma (P < 0.05) compared to fresh. Only display day effect was observed in a*, showing lower redness at the end of the display (P < 0.05). No retail case effect was observed for any color trait. Previously frozen chops tended (P < 0.10) to have lower WBSF values than fresh chops.

Conclusion: The results showed that the type of display case had minimal impact on pork quality, mainly increasing display loss during retail. However, freezing significantly increased the discoloration and moisture loss of chops in the display. In contrast, freezing lowers WBSF in pork, indicating improved tenderness.

Keywords: closed-door display cases, color stability, freezing pork, pork quality

77 ODOR EVALUATION OF CELL-CULTURED FAT

A. Gonzalez^1,*, T. L. Duarte¹, H. Guo¹, R. Alyssa¹, P. Vahmai¹, X. Yang¹, ¹Animal Science, University of California Davis, Davis, California, United States *alagonzalez@ucdavis.edu

Objectives: Research in cultured meat is gaining popularity but primarily focuses on cultured muscle. However, it is important to study cultured fat since fat is a key determinant of meat odor and flavor, which can influence customer acceptance. For example, the quintessential flavor of cooked lamb can be attributed to the increased concentration of short-chain branched fatty acids (BSCFA) like 4-methyloctanoic acid (4-Me8:0), 4-ethyloctanoic acid (4-Et-8:0), and 4- methylnonanoic acid (4-Me-9:0). Therefore, a key target is maintaining crucial sensory properties similar to that of conventional products. The objective of this study was to determine if the addition of volatile fatty acids traditionally found in lamb fat to the adipocyte culture media can generate an odor that resembles traditional lamb fat.

Materials and Methods: Sensory evaluation (IRB #1785273-1) was conducted at the University of California, Davis. A total of 12 panelists were recruited and trained over 10 wk on how to accurately identify lamb fat odor. During the training, panelists were asked to differentiate between several types of fat, including lamb, beef, pork, and vegetable oil. Following training, a triangle test was used to determine eligibility. On the day of evaluation, 9 qualified panelists were asked to evaluate 6 sets of cooked fat samples. Each set contained a lamb fat sample (CON) and 2 bovine-cell cultured fat samples. The 2 bovine-cell cultured samples had BSCFA added to either the growth media (pre-harvest, C) or directly to the cell pellets (post-harvest, T). Samples (3 mg) were placed into glass vials and cooked at 170°F for 100 s using a dry heat block, and then the vials were capped and kept in the heat block at 55°C. Qualified panelists were asked to evaluate samples and indicate their level of similarity to lamb fat using a 3-point hedonic scale (0 = no difference, 1 = slight difference, 2 = large difference). The least-squares means were calculated to report the average evaluation score for each treatment. Data were analyzed using the Kruskal-Wallis test to determine the significant difference. The Dunn’s test with P value adjustment following Bonferroni methods was used for post hoc pairwise comparisons utilizing R (version 4.3.1) with an alpha level of 0.05.

Results: The CON samples were identified as lamb fat by all the panelists, with an average score of 0.18. The T and C samples were rated as being significantly different (P < 0.05) from CON samples, with average scores of 1.83 and 1.74, respectively. This indicated that neither T nor C samples smelled like lamb fat. Furthermore, during the evaluation session, panelists were also asked to add comments to describe the smell of the samples. The odor of sample C was described as being similar to burned plastic or having a strong chemical odor. Similarly, the odor of sample T was described as also smelling like burned plastic, vegetable oil, or being odorless.

Conclusion: As trained panelists did not detect lamb fat odor from either pre-harvest (C) or post-harvest (T) samples, the results suggested that the addition of BSCFA in cell-cultured fat may not be an effective method for generating lamb odor and flavor. Future studies should focus on the addition of beneficial long-chain fatty acids (LCFA) due to their ease of incorporation into adipocytes as well as their ability to enhance the nutritional value of the final product, which will help to make it more competitive in the market.

Keywords: cultured fat, fat, fat odor, lamb, sensory evaluation

78 STREAM TO STORE: TRADITIONAL VS. ALTERNATIVE SLAUGHTER METHODS’ IMPACT ON WHOLE RAINBOW TROUT (ONCORHYNCHUS SPP.) QUALITY AND SHELF LIFE

T. L. Duarte^1,*, Y. Feng¹, S. Talukder¹, B. Bolkenov¹, J. Gross¹, X. Yang¹, ¹Animal Science, University of California Davis, Davis, California, United States *tlduarte@ucdavis.edu

Objectives: In the U.S., rainbow trout are the second most produced finfish species, valued at over $90 million in 2022. However, fresh fish are extremely perishable, and product quality can be drastically influenced by pre-harvest stress, which can be caused during the slaughtering process. Currently, there are numerous acceptable slaughtering methods for fish ranging from blunt force trauma to hypothermia. There has been a long-standing argument regarding the capacity of fish to feel pain. This along with the wide range of methods utilized has led to a knowledge gap as to which methods produce quality products while minimizing pain and suffering. Therefore, the objective of this study was to evaluate traditional and alternative slaughtering methods and their subsequent impacts on the quality and shelf life of whole trout.

Materials and Methods: A total of 54 trout were harvested utilizing a traditional method, submersion in ice slurry (ICE; n = 18), or an alternative method; electricity (EL; n = 18), or nonpenetrating captive bolt (CAP; n = 18). Following slaughter, fish were placed on ice and transported to the UC Davis meat lab, gutted and cleaned. Gutted fish were packaged on polystyrene trays, overwrapped, and placed in a retail display case for 6 d at 2°C (n = 6/group/d). Objective color was measured every 24 h using a portable spectrophotometer on 3 locations and reported as an average for each fish. On days 0, 3, and 6 panelists (n = 6) were asked to evaluate the overall appearance, gill color, eye appearance, overall odor, and gill odor of samples using a 3-point scale (1-Desirable, 2-Acceptable, 3-Unacceptable). Samples were then taken from the right side to determine microbial counts for aerobic mesophilic bacteria, Enterobacteriaceae, and Pseudomonas, and for thiobarbituric reactive substances assay (TBARS; mg MDA/kg meat). Three 1.5 × 1.5 × 3 cm pieces were cut from the left side for texture profile analysis (TPA). Data were analyzed using a two-way ANOVA to investigate treatment, display time effect, and their corresponding interactive effects. The alpha level was defined as 0.05.

Results: The objective color of whole fish was not impacted by treatment. However, panelists rated the eye appearance and gill color of CAP and EL samples more favorably (P < 0.05) compared to ICE samples. The microbial counts of all bacteria types increased over display time regardless of treatment. Interestingly, CAP samples had lower (P < 0.05) microbial counts for all bacteria types than EL or ICE samples. Additionally, TPA showed that treatment did not (P > 0.05) impact values for hardness, cohesiveness, or springiness. However, there was an interactive effect between display day and treatment for adhesiveness, with ICE samples increasing in value over time. In addition, slaughtering method did not impact TBARS values. The CAP and EL samples remained consistent over time while ICE samples slightly increased (P < 0.05) as display time increased.

Conclusion: Results indicated that the alternative methods (EL or CAP) resulted in a higher quality product compared to the traditional method (ICE). More research is needed to compare these alternative methods with other traditional methods such as pithing and blunt force trauma with other economically important large fish species like white sturgeon.

Keywords: fish, meat quality, rainbow trout, shelf life, slaughter

79 EFFECTS OF PORK BELLY FROZEN STORAGE TIME ON BACON SHELF LIFE

J. Mcdonald^1,*, B. N. Harsh¹, A. C. Dilger¹, ¹Animal Sciences, University of Illinois Urbana-Champaign, Urbana, Illinois, United States *jm93@illinois.edu

Objectives: U.S. demand for bacon has increased in recent years, resulting in the need for more pork bellies. Processors may turn to the incorporation of frozen pork bellies to meet the growing demand. Therefore, the objective of this study was to assess visual and flavor differences of layout food service bacon and retail packaged bacon produced from fresh bellies or frozen bellies stored for 6 mo or 12 mo prior to processing

Materials and Methods: Pork bellies (N = 75) from 3 treatments, fresh bellies (Fresh) and bellies frozen for 6 mo or 12 mo, were processed into bacon at a commercial facility with 25 bellies per treatment. Bacon from each belly was packaged into both retail vacuum packages and as layout food service bacon. Retail bacon packages were stored under refrigeration and evaluated at 0, 60 and 120 d after packaging. Food service bacon was stored frozen and evaluated at 30, 60, and 90 d after packaging. Bacon packages were placed into a retail display case and evaluated by trained panelists for visual assessment of discoloration, cured color intensity, and overall acceptability. Bacon was then cooked in a 176°C oven until edges were golden brown (approximately 18 min), cut into pieces, and served to trained panelists to assess oxidative flavor and odor, and off-flavor. Data were analyzed as a RCBD with repeated measure of belly number, the fixed effects of storage time and belly treatments. Belly within panel day for each storage time served as a fixed block, and serving order was used as a random effect for sensory panel analysis. Means were separated within storage time, and significance was determined at P < 0.05.

Results: Bacon from fresh bellies had greater fat percentage than 12 mo bacon (P < 0.01), and 6 mo bacon fat percentage did not differ from either treatment (P > 0.10). For food service bacon, bacon from fresh bellies had a greater discoloration at d 30 and d 60 than 6 mo and 12 mo bacon (P < 0.05), which did not differ (P > 0.10) from each other. At d 90, bacon from fresh bellies and 12 mo discoloration was greater than 6 mo (P < 0.05). Bacon from fresh bellies had less cured color intensity than 12 mo bacon across all time points (P < 0.05). At storage d 30 and d 60, 12 mo bacon had greater oxidative flavor and oxidative odor than bacon from fresh bellies and 6 mo bacon (P < 0.05), which did not differ (P > 0.27). At d 90, there were no differences between treatments for oxidative flavor, odor, or off-flavor (P > 0.41). For retail bacon packages, bacon from fresh bellies had greater discoloration at d 60 and d 120 than 6 mo or 12 mo bacon (P < 0.05), which did not differ from each other (P > 0.10). Bacon from fresh bellies had the least cured color intensity at d 60 (P < 0.05), and there were no differences in cured color intensity at d 120 (P = 0.83). Bacon from fresh bellies was the least visually acceptable at d 120 (P < 0.05). At both d 60 and 90, 12 mo bacon had the greatest oxidative flavor (P < 0.05). There were no differences in oxidative odor at all storage times (P > 0.41).

Conclusion: Bacon produced from frozen bellies stored for 6 and 12 mo had minor differences from bacon produced from fresh bellies and are suitable to incorporate into standard bacon production. Further research on 12 mo frozen bellies’ oxidative properties is needed to minimize oxidative flavor impact if used in production facilities.

Funding Source: Funded, in part, through a gift from Smithfield Foods.

Keywords: bacon quality, discoloration, frozen, oxidation

80 NATIONAL PORK RETAIL BENCHMARKING STUDY

C. C. Carr^1,*, J. M. Young², D. J. Newman³, ¹Animal Sciences, University of Florida, Gainesville, Florida, United States, ²Animal Sciences, North Dakota State University, Fargo, North Dakota, United States, ³Market Growth, National Pork Board, Des Moines, Iowa, United States *chadcarr@ufl.edu

Objectives: The National Pork Retail Benchmarking project is a pork quality audit from the perspective of the U.S. retail consumer. The National Pork Board funded 3 iterations of the project in 2015, 2018, and 2022 with the intent to measure the quality of pork loin chops available to consumers within each year’s snapshot in time and to measure change over time.

Materials and Methods: A total of 1178, 1042, and 2804 boneless center-cut loin chop packages were evaluated in store for subjective color and marbling for the 2015, 2018, and 2022 benchmarks, and a total of 2269, 694, and 2318 individual chops were evaluated for objective tenderness, for each of the same respective iterations. All traits were analyzed using the mixed procedure of SAS. Year, marketing region, and their interaction, along with retailer, were fit as fixed effects. Least-squares means for the year main effect were calculated using the LSMEANS statement. The Tukey adjustment was used, and means that differed by P ≤ 0.05 were considered significantly different. The frequency procedure with the chi-squared test in SAS was used to determine if frequencies differed between years.

Results: The percentage of enhanced (added solution) pork available as a portion of packages displayed at retail declined from almost 28% in 2015 to less than 4% by 2022. However, other than retail availability, no enhanced chops are included in these data. Chops from the 2022 benchmark were subjectively more reddish-pink in the store (P < 0.05) than the previous two benchmarks. Yet chops from the 2018 and 2022 benchmarks were objectively lighter by almost a full L* unit (P < 0.05) than in 2015. Also, in-store marbling was greater (P < 0.05) from the 2018 and 2022 benchmarks than in 2015. The percentage of chops categorized as “not tender” decreased (P < 0.001) from the 2015 sample to the 2018 benchmark, with a greater reduction categorized as “not tender” (P < 0.001) by the 2022 benchmark.

Conclusion: Collectively, the benchmark data indicate that processors have greatly reduced production of moisture enhanced pork. Additionally, pork color has trended lighter objectively, but chops also have a more reddish-pink color in the store. Objective tenderness exhibited a notable improvement over the 3 iterations. These differences are likely driven by several industry changes, including increasing carcass weight and genomic selection which impact chill rate, color, and objective cooked tenderness. Additionally, new and upgraded processing facilities have come online since the first iteration, and multiple facilities have adopted carbon dioxide stunning and/or improved chilling technology, all of which have impacted quality. Retail benchmarking serves as a valuable instrument for stakeholders to assess the impact of the entire industry value chain on pork quality. Furthermore, it helps to understand factors associated with consumer behavior.

Funding Source: National Pork Board

Keywords: pork, enhancement, benchmark, color, tenderness

81 ANTIBODY AND CELL-MEDIATED RESPONSES ASSOCIATED WITH IN VITRO BVDV STIMULATION WITH CORRELATION TO CARCASS PERFORMANCE TRAITS IN ANGUS-BRAHMAN F₁ CROSSES

M. Chapman^1,*, S. M. Falkenberg², K. B. Gehring¹, A. D. Herring¹, ¹Animal Science, Texas A&M University, College Station, Texas, United States, ²NADC, USDA, Ames, Iowa, United States *mackenzie.chapman@tamu.edu

Objectives: This study used Angus-Brahman reciprocal F₁ crosses to investigate potential cellular responses when stimulated in vitro with Bovine Viral Diarrhea Virus (BVDV) 1 and 2, and to evaluate the relationship between carcass performance traits and evaluated immune traits.

Materials and Methods: The influence of reciprocal cross type on cell-mediated immune responses following in vitro exposure to BVDV, and its correlation to carcass performance traits, were evaluated in Brahman-Angus F₁ crosses. Twenty-four steers, evenly balanced across cross type (Angus-sired, AB, vs. Brahman-sired, BA), were studied for cell-mediated response assays. At 7 mo of age, blood samples were collected prior to modified-live vaccination (MLV), and again 8 wk post MLV to allow time for an adequate immune response. Blood was analyzed for humoral and cell-mediated responses using VN ELISA and PrimeFlow RNA assays, respectively. Cultured cells were exposed in vitro to BVDV1 and BVDV2 strains. Following vaccination, steers were grass-fed for 4 mo at Texas A&M McGregor Center before finishing at a commercial feedlot. Steers were harvested at 18 mo of age at a commercial processing facility, and carcasses were evaluated for typical quality and yield component traits. Mixed model ANOVA and correlation analyses were utilized.

Results: No differences were seen due to cross type, virus-neutralizing antibody titers level, or frequency of cultured cells positive for BVDV; however, an interaction between cross and titer level was present for ribeye area (P = 0.039), and the interaction between cross and frequency of BVDV-positive cells was suggestive for hot carcass weight (P = 0.069). Brahman-sired steers with high BVDV1 titers had the lowest hot carcass weight (353.6 ± 0.6 kg) and was at least 12 kg lower than other combinations. Among F₁ cross and BVDV-positive cell category combinations, Brahman-sired steers with low frequency BVDV-positive cells had the smallest ribeye area (72.7 ± 0.24 sq cm) and were at least 3.7 sq cm smaller than other combinations. Ribeye area was positively correlated (r = 0.50, P = 0.019) to frequency of total BVDV-positive cells when stimulated with BVDV1, as well as CD8+ cells that were BVDV-positive (r = 0.45, P = 0.037); antibody titers were also positively correlated to ribeye area (P = 0.037). However, these trends were not present when cells were stimulated with a BVDV2 strain. Ribeye area was the only carcass performance trait that was significantly correlated to any immune system responses in this study. Marbling score was the only quality trait recorded. There were no differences observed in marbling scores between cross types. The difference in ribeye area did not appear to impact marbling score.

Conclusion: There were limited correlations between performance carcass traits and evaluated immune traits, solely concentrated in ribeye area evaluation. This is potentially encouraging to producers as altering immune system responses from both humoral and cell-mediated traits do not appear to have immense negative impact on carcass quality traits.

Funding Source: This study was a component of USDA CSREES Hatch project TEX08937 and supported by Texas A&M AgriLife Research.

Keywords: beef quality, carcass quality traits, cell-mediated, immune response

82 ANIMAL GROWTH PATH AFFECTS THE EXPERT SENSORY CHARACTERISTICS, CARCASS TRAITS, AND VOLATILE AROMA COMPOUNDS OF COOKED LAMB

N. Barrett^1,*, C. R. Kerth¹, R. K. Miller¹, N. Schaff², J. A. Boles², ¹Animal Science, Texas A&M University, College Station, Texas, United States, ²Animal and Range Sciences, Montana State University, Bozeman, Montana, United States *c-kerth@tamu.edu

Objectives: We hypothesized that creating a period of slow growth prior to entering the feedlot for finishing would impact lamb flavor and volatile aroma compounds.

Materials and Methods: Twenty range lambs were brought in for processing and weaned at the time of herd breeding (average of 234 d of age) and assigned to 2 different growth paths. Ten were placed immediately in the feedlot and fed a standard feedlot ration for 35 d until the average weight for the group was 52 kg (Feedlot; 269 d of age at harvest). The second group of 10 was overwintered on grass hay and then turned out on native range after the snow melted before entering the feedlot (Grazed). In July, the lambs were placed in the feedlot and fed a standard feedlot ration to match days in the feedlot and weight to the Feedlot lambs (473 d of age at harvest). Carcass traits (carcass weight, fat thickness, longissimus muscle area, leg confirmation score, flank streaking) were measured, and loin samples were obtained 24 h after harvest. The loins were vacuum packaged and transported to the MSU meat lab. The loins were boned at the meat lab, vacuum-packaged and frozen. These samples were shipped to Texas A&M University for volatile flavor compound analysis and sensory flavor profile analysis. A 6-member expertly trained sensory panel tested 6 or 7 loin chop samples daily using a 15-point scale for lamb lexicon flavor descriptors along with texture and juiciness scores. Simultaneously, about 5 g of each warm sample was frozen in liquid nitrogen and transferred to the −80°C freezer until gas chromatography (GC) volatile analyses were performed. For volatile analyses, frozen samples (along with 10 uL of 1,3-dichloro-benzene as an internal standard) were placed in a 20 mL glass vial in a heating block (60°C) for 30 min. Then a PDMS-Carboxin solid-phase microextraction (SPME) sampler was inserted into the vial to adsorb the volatile compounds for 20 min. The SPME was then inserted into the injection port of a 7820 Agilent gas chromatograph (GC), where compounds were desorbed for 3 min and then released onto a 30 m BPX5 capillary column. Following a ramp (7°C per minute) in the temperature of the GC, volatile compounds were separated and proceeded to an Agilent 5975 mass spectrometer (MS) for identification and quantification. Data were analyzed as a 1-way analysis of variance with the sensory panelist by treatment interaction being tested and found not to be significant (P > 0.05). Therefore, sensory scores were averaged across panelist, and order served as a random effect and animal production scenario (Feedlot vs Grazed) as a fixed effect. Alpha was set at 5%.

Results: Grazed lambs had higher levels of sensory painty/fishy, bitter, and mutton flavors and higher sensory scores for myofibrillar tenderness and connective tissue amount compared to Feedlot lambs (P < 0.05). Grazed lambs had chops that had higher levels of pentanoic acid, methyl ester, dihydro-2(3H)-furanone, and 2,3-butanediol as well as lower levels of 2-octanone, 1-penten-3-ol, 2,5-dimethyl-pyrazine, thiobis-methane, and methoxy-acetic acid (P < 0.05). While not impacted by the finishing scenario (P > 0.05), volatiles found in the highest concentration were 3-hydroxy-2-butantone, 2-propanone, carbon disulfide, 3-methyl-butanal, and 2-methyl-butanal.

Conclusion: Lambs having a period of slow growth while grazing pasture followed by finishing in a feedlot resulted in higher levels of negative sensory flavor descriptors and lower concentrations of positive volatile compounds.

Funding Source: Funding provided by the Bair Ranch Foundation.

Keywords: carcass, finishing system, lamb, sensory, volatiles

83 IMPROVING MEAT QUALITY AND SENSORY ATTRIBUTES OF FROZEN/THAWED AND REPEATED FROZEN BEEF SIRLOINS THROUGH POSTMORTEM AGING

S. U. Rehman^1,*, J.-K. Seo¹, D.-J. Shin¹, M. R. Romanyk¹, B. Kim¹, ¹Department of Animal Sciences, Purdue University, West Lafayette, Indiana, United States *rehmans@purdue.edu

Objectives: Freezing is an effective preservation method for upholding the quality and shelf-life of meat products. Adverse impacts of freezing, however, on texture, color, water-holding capacity, or possibly sensory attributes have been reported. In particular, given repeated freezing is a common practice in households, it may lead to additional quality deterioration if previously frozen/thawed meat undergoes repeated freezing and thawing, resulting in consumer dissatisfaction. Several studies have reported that postmortem aging can minimize quality discrepancies between fresh and frozen/thawed meat. The objective of this study was to determine the impact of aging before freezing and repeated freezing on quality attributes of beef sirloin.

Materials and Methods: At 5 d postmortem, pairs of 40 sirloins (gluteus medius) were collected from 20 beef carcasses (USDA Choice). Each sirloin was randomly assigned to no further aging (A0) or 4 wk aging (A4). Subsections were taken for initial samples, then subjected to either single freezing-thawing (A0FT and A4FT) or repeated freezing-thawing (A0FT×2 and A4FT×2) conditions for 3 wk. Following aging (2°C), freezing (−20°C), and thawing (2°C), the samples were evaluated for color, Warner-Bratzler shear force (WBSF), water-holding capacity (WHC), myofibrillar fragmentation index (MFI), 2-thiobarbituric acid reactive substances (TBARS), and consumer panel sensory evaluation (n = 120). The statistical analysis was performed using SAS 9.4 PROC GLIMMIX procedure, with significance assessed via F-test (P < 0.05).

Results: Purge loss was higher in A4 compared to A0 (P < 0.05). However, freezing only (no aging) led to higher freeze-thaw and drip losses in A0FT and A0FT×2 compared to A4FT and A4FT×2 (P < 0.05). Moreover, repeated freezing consistently increased freeze-thaw loss (P < 0.05). No differences were found in cooking loss and WHC (measured by compression losses) between treatments (P > 0.05). Freezing and repeated freezing consistently resulted in decreased WBSF values (P < 0.05), with A0FT and A4FT showing lower WBSF values compared to A0 and A4 treatments, respectively (P < 0.05). Additionally, repeated freezing further decreased WBSF values regardless of aging status (P < 0.05). MFI was higher in A0FT and A4FT compared to A0 and A4, respectively (P < 0.05), with no difference between once and repeatedly frozen samples (P > 0.05). Both freezing and repeated freezing resulted in an increase in TBARS levels, regardless of the aging time (P < 0.05). Consumer panel found that aging improved tenderness and overall-likeness of beef sirloins, while no negative impacts of repeated freezing on sensory attributes were determined (P > 0.05). Freezing with no aging decreased CIE L*a*b* and chroma values of beef sirloins (P < 0.05). However, steaks from aged/frozen (A4FT and A4FT×2) had similar color attributes compared to never frozen counterparts (A4; P > 0.05).

Conclusion: The results demonstrate that freezing and repeated freezing negatively impact WHC. However, aging prior to freezing improved color attributes and WHC of beef sirloins regardless of repeated freezing. Aging, in conjunction with freezing and thawing, resulted in increased myofibrillar protein fragmentation, leading to improved tenderness. This study suggests that developing an aging/freezing strategy has potential to improve meat quality attributes while also offering preservation benefits.

Funding Source: Research coordinated by the National Cattlemen’s Beef Association, a contractor to the Beef Checkoff.

Keywords: beef sirloin, aging/freezing, repeated freezing, meat quality, sensory evaluation

84 IMPACT OF SPOILAGE BACTERIA ON BEEF STEAK COLOR STABILITY

C. L. Smith^1,*, I. Geornaras¹, M. N. Nair¹, ¹Department of Animal Sciences, Colorado State University, Fort Collins, Colorado, United States *colton.smith@colostate.edu

Objectives: Meat wastage due to discoloration is economically and socially burdensome for the meat industry. Although the biochemical basis of meat discoloration and microbial growth during retail display has been investigated independently, there is only a limited understanding of the interplay between the growth of spoilage microflora and meat color. Therefore, the objective of this study was to investigate the impact of the growth of common spoilage bacteria on the color stability of color-stable (longissimus lumborum; LL) and color-labile (psoas major; PM) beef muscles during retail display.

Materials and Methods: Eight (n = 8) USDA Choice beef striploins (LL) and tenderloins (PM) were wet-aged for 14 d, after which their surfaces were decontaminated by submerging in boiling water to reduce the natural microbial contamination level. The muscles were then fabricated into 1.27-cm-thick steaks and assigned to either a decontaminated control (DCON) or inoculated (INOC) treatment. The surface of INOC steaks was inoculated (ca. 4 log CFU/cm²) with a mixture of 5 spoilage bacteria, while an equivalent volume of phosphate-buffered saline was applied to the surface of DCON steaks. Steaks were overwrapped and placed in a retail display case (3°C) for up to 9 d. Each day, objective and subjective color evaluation and microbiological analysis (aerobic, Pseudomonas spp., and lactic acid bacteria plate counts) were conducted on one steak per loin per treatment. Bacterial growth kinetics of the populations recovered from the INOC LL and PM steaks were modeled with the Baranyi-Roberts model to provide lag phase duration and maximum specific growth rates. Using the Lme4 and LmerTest packages in R, data for LL and PM were analyzed in separate factorial models, testing for a treatment × day interaction, with carcass used as a random variable. Means were separated with ANOVA and the emmeans package in R and significance was set to a = 0.05.

Results: There was a treatment × day interaction (P < 0.05) for lightness (L*), redness (a*), yellowness (b*), lean color scores, surface discoloration, and bacterial population levels for LL steaks. On days 6 through 8, redness was lower (P < 0.05) for INOC compared to DCON LL steaks, while lean color scores and surface discoloration were lower (P < 0.05) for DCON compared to INOC LL steaks. For PM, there was a treatment × display day interaction (P < 0.05) for a* values, surface discoloration, and bacterial levels. Surface discoloration was greater (P < 0.05) for INOC PM steaks compared with DCON steaks on days 4 and 5. Further, bacterial growth kinetics showed that lag phases of aerobic bacterial populations on LL steaks (2.2 d) were longer compared to those on PM steaks (<1 d).

Conclusion: These results established that bacterial growth could directly impact the rate of surface discoloration and redness of LL and PM beef steaks during aerobic retail display. Further, the results suggest that there could be muscle-specific mechanisms impacting bacterial growth kinetics which are contributing to the muscle-specific discoloration of beef muscles.

Funding Source: Research coordinated by the National Cattlemen’s Beef Association, a contractor to the Beef Checkoff.

Keywords: color stability, microbial growth, shelf-life

85 EFFECTS OF ALTERNATIVE FINISHING METHODS ON COLOR AND TENDERNESS CHARACTERISTICS OF BEEF STEERS

M. L. Johnson^1,*, S. L. Shoup¹, S. E. Shimer¹, C. E. Gruber¹, D. Setyabrata², J. W. S. Yancey¹, D. Rivera³, K. R. Vierck¹

¹Department of Animal Science, University of Arkansas, Division of Agriculture, ²Department of Animal Science, University of Arkansas, Fayetteville, Arkansas, United States, ³Department of Animal Science, University of Arkansas, Division of Agriculture, Southwest Research & Extension Center, Hope, Arkansas, United States *mj057@uark.edu

Objectives: The objective of this study was to evaluate the effect of alternative finishing methods on color stability, cook loss, and Warner-Bratzler shear force (WBSF) values of beef steers.

Materials and Methods: Crossbred beef steers (n = 63; body weight [BW] = 363.9 ± 28.7 kg) were blocked by BW and assigned to pens (n = 3 steers/pen) with 7 pens randomly allocated to one of 3 dietary treatments: conventional feedlot finishing diet with roughage included in the ration (FDLT); high starch supplement fed at 2%–2.25% of BW with ad libitum access to bermudagrass pasture (STCH); or high by-product supplement fed at 2%–2.25% of BW with ad libitum access to bermudagrass pasture (BYPD). Steers were fed their diets once daily and weighed every 28 d. Once finished, steers were transported to and harvested at a commercial slaughter facility, where strip loins were collected from the left side of each carcass. Strip loins were vacuum packaged, wet aged for 21 d, then fabricated into 2.54-cm-thick steaks. Steaks designated for color analysis were packaged in overwrap packaging and placed in a simulated retail display in a multideck case under continuous 3500 K LED lights for 7 d. All color measurements were collected every 12 h utilizing a spectrophotometer. Steaks designated for WBSF analysis were vacuum packaged and frozen at −20°C. Steaks were thawed at 0–4°C for approximately 18 h, weighed, and cooked using clamshell grills until samples reached an internal temperature of 71°C, and then were re-weighed to measure cook loss. Steaks were then refrigerated for 12 h, then six 1.27 cm cores were removed parallel to the muscle fiber from each steak and used for WBSF analysis. Color data were analyzed using PROC MIXED with repeated measures and cooked measurements were analyzed using PROC GLIMMIX; diet and day were fixed effects, time of day was a random effect, and peak temperature was incorporated into the model as a covariate. Statistical differences were determined at α ≤ 0.05.

Results: A diet × day interaction (P < 0.001) occurred for a*, chroma, and hue. For a* and chroma, no differences (P > 0.05) were observed on d 0, 1, 2, or 3 of display. However, after 3 d of display, steaks from cattle fed FDLT were less red with a lower saturation index compared to steaks from cattle fed STCH and BYPD, with the greatest separation occurring on d 7 (P ≤ 0.001). This indicates steaks from steers fed FDLT did not maintain as bright of a red color during retail display compared to STCH and BYPD. For hue value, FDLT steaks had a greater (P < 0.001) hue angle than STCH and BYPD on d 5, 6, and 7, indicating FDLT steaks had the most discoloration during the display period. There were no diet × day interactions (P ≤ 0.99) for L* and b* values. Diet resulted in greater (P < 0.0001) L* values for BYPD and FDLT compared to STCH. However, diet resulted in greater (P < 0.0001) b* values for BYPD and STCH compared to FDLT. A significant effect of day (P < 0.0001) resulted in L* and b* values decreasing over 7 d. Cook loss was greater (P = 0.01) for FDLT compared to STCH and BYPD. Steaks from cattle fed BYPD had lower (P = 0.02) WBSF values than steaks from FDLT and STCH.

Conclusion: These results indicate that supplementing cattle grazing pasture could significantly impact instrumental color differences, cook loss, and WBSF values and successfully serve as an alternative finishing method without detriment to color and tenderness.

Funding Source: This research was funded by the Arkansas Beef Council.

Keywords: beef, color stability, feeding strategies, local production, tenderness

86 COMPARING THREE CAMERA TECHNOLOGIES’ ABILITY TO PREDICT INTRAMUSCULAR FAT PERCENTAGE IN F1 WAGYU CATTLE

D. M. Velazco^1,*, M. N. Nair¹, H. Ostrovski², R. Williams², R. J. Delmore¹, J. N. Martin¹, K. E. Belk¹, J. A. Scanga¹, ¹Animal Sciences, Colorado State University, Fort Collins, Colorado, United States, ²Animal Sciences, American Wagyu, Post Falls, Idaho, United States *velazco@colostate.edu

Objectives: The prevalence of highly marbled cattle breeds, such as Wagyu, has increased in the U.S. due to consumer demand for higher-quality beef. However, the ability to assign quality grades to highly marbled carcasses accurately and consistently, particularly while quantifying intramuscular fat content, remains a challenging task for the Wagyu beef industry. New camera grading technologies have been proposed by VIAS VBG 2000 (E + V), Meat Image Japan (MIJ), and MasterBeef (MB) for Wagyu-influenced beef carcass assessment based on advanced image analysis. However, the relationship between intramuscular fat measurements of these camera technologies and the actual percent intramuscular fat (% IMF) in the longissimus thoracis muscle at the 12/13th rib has yet to be investigated. Therefore, the objective of this study was to compare E + V, MIJ, and MB cameras’ ability to predict % IMF in F1 Wagyu cattle.

Materials and Methods: Chilled carcasses (n = 173) from F1 Wagyu cattle were ribbed between the 12th and 13th ribs, and the left sides of the carcass were imaged with the E + V, MIJ, and MB cameras. Additionally, the marbling score was assigned by a team of 3 USDA graders. Samples from the longissimus thoracis were collected, and subcutaneous fat was removed. The samples were then flash frozen using liquid nitrogen and the % IMF of the muscle was determined through lipid extraction using chloroform and methanol as organic solvents. Data were exported from all 3 camera systems into Microsoft Excel and checked for missing values. Linear regressions were performed using JMP (Statistical Discovery, NC. USA) software analyzing the relationship between two variables using the fit Y by X function.

Results: Fat-related camera measurements were linearly correlated to % IMF, and R² was calculated for all cameras. The E + V camera had the highest % IMF predictability of all cameras (P < 0.0001) using the marbling score (R² = 0.64). The MIJ camera presented intermediate predictions (P < 0.0001) of % IMF with identical R² for fat percent and fat score estimates (R² = 0.59). The MB camera had the lowest predictability (P < 0.0001) of % IMF using the measured marbling score (R² = 0.32), marbling area (R² = 0.33), and marbling percent (R² = 0.32) estimates from the instrument.

Conclusion: This study compared the capability of E + V, MIJ, and MB to predict intramuscular fat in the longissimus thoracis of F1 Wagyu cattle. The E + V camera had the highest R² with the % IMF followed by USDA graders, MIJ, and MB, respectively. The development of new camera systems to accurately predict % IMF will be a useful tool for grading Wagyu-influenced beef carcasses.

Keywords: camera grading quality

87 FREEZING AND THAWING PRACTICES USED IN THE BEEF INDUSTRY

B. E. Lamb^1,*, I. M. Lovell¹, J. W. Savell¹, K. B. Gehring¹, ¹Animal Science, Texas A&M University, College Station, Texas, United States *belamb02@tamu.edu

Objectives: The objective of this study was to identify nationwide freezing and thawing practices including time, temperature, product type, freezer technology, and other non-direct packaging characteristics of beef.

Materials and Methods: To collect data, the USDA-FSIS list of all USDA-inspected facilitates was downloaded and filtered to isolate establishments specifically engaged in “Meat Slaughter” and/or “Meat Processing” under the “Activities” column. Surveyed plant size and location varied, offering a widespread representation of plants across the U.S. After the filtering process, establishments were contacted via telephone and asked a series of questions related to freezing and thawing of beef. The survey included questions about 1) basic plant information, 2) freezing of products, 3) thawing of products, and 4) open-ended questions about ways the plant could improve its freezing and thawing practices.

Results: A total of n = 1,798 establishments were selected and contacted from the USDA-FSIS database, and n = 261 completed the survey. Two common reasons for not completing the survey included being unwilling to participate or not producing beef products. Of the 261 establishments, 42.4% represented slaughter and fabrication facilities, with 104 that froze and thawed beef products, 124 that only froze beef products, and 4 that only thawed beef products. For plants that froze beef, 35.2% froze primals/subprimals, retail cuts, and trimmings/ground beef, and 21.6% froze only retail cuts and trimmings/ground beef. The freezer technology most utilized was “still air” (44.9%), and the second most common was “blast” (35.6%). When asked how products were frozen, 16.5% reported products were placed on trays for freezing before boxing, and 16.5% also reported placing products in a box and stacking them on pallets for freezing. Reported freezing times were commonly between 6 and 24 h (50.00%) and 24 and 48 h (24.8%), with a mean temperature of −22°C. When thawing beef, 27.3% reported placing boxes in a single layer on a shelf, and 13.6% thawed entire pallets of boxed products. Thawing times most reported were 24 to 48 h (23.8%) and 48 to 72 h (16.6%), with a mean temperature of 3.1°C. The maximum and minimum freezing temperatures based on the reported data were −51.1°C and −1.7°C, respectively, while the maximum and minimum thawing temperatures were 19.7°C and −1.9°C, respectively. When asked how freezing and thawing practices could be improved, 53.5% of establishments responded with needing more freezer space, 28.3% wanted to increase the freezing rate, and 8.1% wanted to increase the thawing rate. The most commonly reported packaging issue was leaking packages during thawing.

Conclusion: For years, the slogan “freeze fast, thaw slow” has been used as recommended procedures for freezing and thawing beef products. Based on survey data, a large proportion of establishments do not adhere to this approach and utilize suboptimal freezing methods that may negatively impact product quality. Both large and small establishments reported facing similar issues regarding freezer space and the need to minimize freezing and thawing times. Additional information and/or best practices for freezing and thawing may be necessary to safeguard beef quality from potential adverse effects.

Funding Source: Research coordinated by the National Cattlemen’s Beef Association, a contractor to the Beef Checkoff.

Keywords: beef quality, freezing, thawing

88 IMPACT OF BROILER CARCASS ORIENTATION AFTER SLAUGHTER ON BREAST MEAT QUALITY WHEN EVALUATING DELAYED PROCESSING

C. Harris^1,*, J. Choi¹, M. Shakeri¹, B. Kong¹, B. Kiepper², J. Buhr¹, H. Zhuang¹, B. Bowker¹

¹U.S. National Poultry Research Center, USDA-ARS, ²Department of Poultry Science, The University of Georgia, Athens, Georgia, United States *caitlin.harris@usda.gov

Objectives: With the standard practices for poultry harvesting, there is the potential for handling and transport conditions to impact bird welfare and meat quality negatively. In prior experiments simulating an alternative processing procedure in which birds are slaughtered on-farm and carcasses transported to the plant to continue processing, a notable effect on meat quality was the reddish discoloration on the cranial end of the raw breast fillets (pectoralis major). In the delayed processing experiments, the carcasses were held upside-down by their shanks on shackles. It is theorized that gravity caused residual blood in the carcasses to pool in the cranial end of the breast muscles, causing discoloration. Therefore, the objective of this trial is to determine if, during the delay post-slaughter, holding the carcasses either on their back or hanging them from the shackle by their neck prior to scalding and de-feathering will reduce discoloration.

Materials and Methods: In total, 120 Cobb, 500 male broilers were selected for 4 treatments (n = 30): Control (no delay), 4-h delay + held by shanks (4S), 4-h delay + held by neck (4N), or 4-h delay + held on back (4B). After electrical shock and bleed-out, carcasses in the Control group were hard-scalded and picked, as standard, while the 3 delay treatments were held for 4 h before scalding/picking. Post-pick, breast fillets from carcasses were hot-deboned and chilled overnight. All fillets were scored on a scale of 1 to 3 for woody breast, white stripping, petechial hemorrhaging, and discoloration (cranial, caudal, and lateral). Individual fillets from each carcass were utilized for pH (before cooking), color (L*a*b*) measurements (before and after cooking), marination uptake (after marination), and Blunt Meullenet-Owens Razor shear force measurements (after cooking). Data were analyzed using JMP Pro 17.0.0 with parametric data analyzed with ANOVA and non-parametric data analyzed with the Kruskal–Wallis test.

Results: Scores for petechial hemorrhaging and discoloration on cranial end of fillets were significantly higher (P = 0.0134 and P < 0.0001, respectively) for the 4S treatment compared to Control. Similarly, the discoloration score on the caudal end of fillets for 4N treatment was significantly higher than Control (P < 0.0001), and discoloration on the lateral side of 4B treatment fillets was significantly higher than Control (P < 0.0001). The discoloration score results were supported by a* values for the raw fillets, with 4S fillets having significantly higher (P = 0.0290) values than 4N fillets, with Control and 4B fillet values being intermediate. After marination, the raw fillets from 4S treatment still had the significantly highest (P = 0.0247) a* values. After cooking the unmarinated fillets, Control treatment had significantly higher (P = 0.0329) a* values compared to the 4B fillets, with 4S and 4N being intermediate. After the marinated fillets were cooked, there were no differences in a* values between the treatments. There were no significant differences between treatments for woody breast scores, white striping scores, cook loss, marination uptake, or tenderness.

Conclusion: Results from this study support the conclusion that gravity caused residual blood to pool in the cranial end of the breast fillets, as holding the carcasses in different orientations during the 4-h delay did impact the discoloration scores and a* values of the fillets.

Keywords: delayed processing, poultry meat quality, poultry processing

89 EVALUATING THE EFFECTS OF DIFFERENT FREEZING METHODS ON INTERNAL COOKED COLOR, COOKING LOSS, AND THAW LOSS OF BEEF STRIP STEAKS

K. Elliott^1,*, J. A. Scott¹, K. Harr¹, B. Robbins¹, M. M. Pfeiffer¹, G. G. Mafi¹, R. Ramanathan¹, ¹Department of Animal and Food Sciences, Oklahoma State University, Stillwater, Oklahoma, United States *madelyn.scott@okstate.edu

Objectives: In recent years, the food industry has turned to freezing methods utilizing solid carbon dioxide and liquid nitrogen to expedite freezing and improve product integrity during transport. These innovations are especially relevant to online meat sales and smaller volume transportation services like ButcherBox. However, little research exists on their impact on internal cooked color, muscle structure, and tenderness in beef. Therefore, the study objective was to determine the effect of blast, liquid nitrogen, or dry ice freezing on cooked color and tenderness attributes of beef strip steaks.

Materials and Methods: USDA Choice beef strip loins were obtained from a commercial beef processing facility and transported to Oklahoma State University for further analysis. Strip loins (N = 7) were stored at 2°C ± 1°C for 12 d postmortem. From the posterior end, 3 steaks (2.54 cm) from the longissimus lumborum muscle were fabricated for freezing and tenderness parameters. Steaks which included portions of the gluteus medius were not used for analysis. One steak from each loin was randomly assigned to a freezing method: blast, liquid nitrogen, or dry ice freezing. Steaks assigned for traditional blast freezing were vacuum packaged and placed in a −20°C blast freezer for 7 d. Steaks assigned for liquid nitrogen freezing were submerged in liquid nitrogen for 4 min, vacuum sealed, and placed in a freezer at −21°C ± 1°C for 7 d. Steaks assigned for dry ice freezing were vacuum sealed and placed in a Styrofoam cooler layered with dry ice and cardboard for 12 h, then were transferred to a freezer at −21°C ± 1°C for 7 d. For slice shear force (SSF) evaluation steaks were thawed for 18 h at 2°C ± 1°C. Once thawed, steaks were weighed in their package, then removed and weighed raw to calculate thaw loss. All steaks were cooked to an internal temperature of 71°C and weighed immediately following cooking to calculate cook loss. Steaks were then allowed to rest a minimum of 5 min. To capture internal cooked color, steaks were cut in half perpendicular to the cooked surface and CIE L*a*b* values were collected with a HunterLab MiniScan spectrophotometer (2.5-cm aperture, Illuminant A, and 10° observer angle). Chroma was determined using CIE a* and b* values, representing the red intensity of the color. Slice shear force (SSF) was conducted in duplicate by taking 2 slices from each steak and averaged. SSF was collected following the AMSA Sliced Shear Force Protocol. The GLIMMIX Procedure of SAS was used to determine the least-squares means. Least-squares means were considered significant at a P < 0.05.

Results: There was a significant difference (P < 0.05) in thaw loss among the 3 freezing methods. Steaks frozen in liquid nitrogen had less (P < 0.05) thaw loss than steaks frozen using blast or dry ice freezing. There were no differences (P > 0.05) in instrumental a*, b*, or chroma values for internal cooked color among all freezing treatments. Additionally, no differences were noted in SSF (P > 0.05) or cooking loss (P > 0.05) among any of the freezing treatment groups.

Conclusion: The results indicate that freezing method has limited impact on cooked color and tenderness attributes of beef strip steaks. Traditional blast freezing and dry ice freezing increases thaw loss in beef strip steaks. The use of other freezing methods, such as dry ice or liquid nitrogen, in combination with traditional methods can minimize freezing time and energy.

Keywords: beef, cooked color, freezing, thaw loss

90 IMPACT OF VISUAL DARK-CUTTING SEVERITY ON THE METABOLOMIC AND LIPIDOMIC PROFILES OF BEEF LONGISSIMUS LUMBORUM

K. M. Harr^1,*, M. A. Scott¹, F. Kiyimba¹, S. More², G. G. Mafi¹, M. M. Pfeiffer¹, R. M. Ramanathan¹, ¹Animal and Food Science, ²Veterinary Pathobiology, Oklahoma State University, Stillwater, Oklahoma, United States *keayla.harr@okstate.edu

Objectives: Dark-cutting beef continues to be one of the challenges the global beef industry faces, causing significant economic losses. To date, limited studies have evaluated varying severities of dark-cutting beef and the subsequent impacts on the metabolomic and lipidomic profiles of beef. Therefore, the objective of this study was to evaluate the impact of varying degrees of dark-cutting severity on the lipidome and metabolome of unaged beef longissimus lumborum.

Materials and Methods: Beef carcasses (n = 8/treatment) were selected based on the visual degree of dark-cutting at the time of grading from commercial beef packing plants. Following fabrication, beef strip loins representing one-half dark, two-thirds dark, full dark, and a normal cherry-red colored control were collected. At 48 to 60 h postmortem, one 2.54 cm steak was cut from each loin for bloom, pH, lipidomic and metabolomic analysis. Steaks were allowed to bloom for 1 h prior to evaluating the color using a HunterLab MiniScan EZ spectrophotometer. Samples from each steak were used for quantitative metabolomics and lipidomics profiling using untargeted gas-chromatography and liquid-chromatography mass spectrometry, respectively. Muscle pH and bloom data were analyzed using the Glimmix Procedure of SAS. Metabolomics and lipidomics data were analyzed using MetaboAnalyst v 6.0. Significant differences across all analyses were determined at an alpha value of 0.05.

Results: A greater (P < 0.05) pH was found in full and two-third dark cutters than normal and half dark-cutter steaks. Full steaks had a lower (P < 0.05) bloomed a* value than normal and half steaks with two-third steaks being intermediate. Metabolomics analysis indicated 122 metabolites observed across treatment groups, of which 58, 42, and 30 metabolites were differentially abundant in full, two-thirds, and half-dark steaks, respectively, compared to normal-colored steaks. Half, two-thirds, and full-dark steaks had downregulation of glycolytic metabolites specifically, glucose-6-phosphate, and fructose-6-phosphate, while glucose, glucose-1-phosphate, and gluconic acid were exclusively less abundant in full and two-third dark steaks compared with normal beef. Full dark-cutter had fewer metabolites exclusive to the pentose phosphate pathway, suggesting a potential role in muscle darkening. Furthermore, full dark-cutters had an abundance of phenylalanine, tyrosine, and tryptophan biosynthesis compared with other shades of dark-cutters. Lipidomic profiling reported 350 lipids across treatments, with 29, 33, and 33 lipids differentially abundant in half, two-thirds, and full dark steaks, respectively, than normal steaks. Among these, 19 lipid species were shared between steaks of different degrees of darkness. Notably, acylcarnitine species of varying carbon length and degree of saturation, were markedly over-abundant in all dark-cutter shades compared to normal steaks.

Conclusion: The upregulation of acylcarnitine species in dark steaks highlights enhanced fatty acid oxidation and shifts in lipid composition associated with muscle darkening, suggesting alterations in mitochondria function and energy metabolism. Furthermore, the concurrent down-regulation of key glycolytic metabolites and enrichment of the pentose phosphate pathway, particularly in full dark steaks, indicates compromised energy metabolism in dark-cutting beef.

Funding Source: Graduate fellowship funding for Keayla Harr provided by the United States Department of Agriculture National Institute of Food and Agriculture National Needs Fellowship Program.

Keywords: beef, color, dark-cutting, lipidomics, metabolomics

91 IMPACTS OF POSTMORTEM AGING ON COLOR ATTRIBUTES AND WATER-HOLDING CAPACITY OF BISON

E. Sierra^1,*, J. Seo¹, Y. H. B. Kim¹, ¹Animal Science, Purdue University, West Lafayette, Indiana, United States *e@2@@3.edu

Objectives: Postmortem aging is a widely practiced method used to increase tenderness in meat through endogenous enzymatic protein degradation. The quality changes associated with aging are well-known for beef, lamb, and pork, but little research exists for bison meat. Limited information is available for the influence of extended aging on initial bloomed color, color stability, and water-holding capacity on bison meat. Given a notable rise in both the production and consumption of bison in North America due its low fat, high protein, and rich flavor attributes, bison meat has the potential for increased quality through aging procedures. The purpose of this study, therefore, was to investigate the impact of extended aging periods on initial blooming ability, color stability, and water-holding capacity (WHC) of bison loins.

Materials and Methods: Paired strip loins (M. longissimus lumborum; n = 30) were collected from both sides of bison carcasses (n = 15) at 7 d postmortem. The loins were divided into 4 equal sections and randomly assigned to the 4 aging treatments: 1-, 7-, 14-, or 21-d aging at 1°C. The muscle sections were vacuum packaged until their respective aging time. Purge and drip loss were measured at each aging time to determine WHC. The bloomed color was performed after exposing the fresh surface of meat cuts for 3 h. Display color of PVC-film over-wrap packaged steaks was carried out under the light for 7 d. All color measurement were recorded in 3 locations of each sample and expressed with their average value. The data analysis employed was PROC GLIMMIX procedure of SAS 9.4 with a significance level of P < 0.05. The means were separated with the least-squares mean differences with the Turkey as post-hoc test.

Results: Both CIE a* and chroma values increased with longer aging times (P < 0.05). There were also significant differences in hue angle and R630/580 values across each aging time during the duration of display time; as aging time increased, the hue angle value increased, where the 21d aged loins had the highest hue angle values at the end of display (P < 0.05). The R630/580 value decreased with aging time (P < 0.05). There was a significantly higher purge loss in 14 d and 21 d than other aging time, while no significant difference was found between the 14-d and 21-d aging treatments. Drip loss decreased with aging time (P < 0.05), though no difference was found between the 14-d and 21-d aged loins (P > 0.05).

Conclusion: The results of this study indicate that aging can improve bloomed color in bison meat, as longer aging periods resulted in more intense and red colored meat. The increased aging, however, had a negative impact on color stability, with the 14-d and 21-d aged loins showing faster discoloration. While aging increased purge loss, drip loss decreased with aging periods, likely due to improved water-holding capacity through proteolysis. This study demonstrates the effectiveness of aging on improving color and WHC in bison loins, as well as identifies implications arising with aging associated with faster discoloration rates and purge loss.

Funding Source: This project is funded by the Center of Excellence for Bison Studies.

Keywords: bison, color, postmortem aging, water-holding capacity

92 LAMB PRE-FINISHING GROWTH RATE IMPACTS THE MUSCLE METABOLOME

C. R. Kerth^1,*, J. A. Boles², N. Schaff², ¹Animal Science, Texas A&M University, College Station, Texas, United States, ²Animal and Range Sciences, Montana State University, Bozeman, Montana, United States *c-kerth@tamu.edu

Objectives: Our objective was to characterize the metabolome of lambs that had different growth rates prior to finishing. We hypothesized that creating a period of slow growth of lambs prior to entering the feedlot for finishing would impact the metabolome in the muscle.

Materials and Methods: Twenty lambs were identified at weaning, weighed, and randomly assigned to 2 different growth paths. Ten were placed immediately in the feedlot and fed a standard feedlot ration for 35 d until the average weight for the group was 52 kg (Feedlot; ave 269 d of age at harvest). The second group of 10 was overwintered on grass hay and then turned out on native range after the snow melted before entering the feedlot (Grazed). In July, the lambs were placed in the feedlot and fed a standard feedlot ration to match days in the feedlot and weight to the Feedlot lambs (ave 473 d of age at harvest). Carcass data and loin samples were obtained 24 h after harvest. The loins were vacuum packaged and transported to the Montana State University meat lab. The loins were boned at the meat lab, vacuum-packaged and frozen. The samples were shipped to Texas A&M University for metabolomics analyses. Raw muscle (200 mg) was extracted with 6.6 mL ice-cold methanol:HPLC water (4:1) followed by 2.4 mL chloroform, shaken for 10 min, and then 2.4 mL chloroform:water (1:1) was added. The sample was centrifuged at 5,000 × g for 10 min at room temperature. The upper aqueous layer (about 8 mL) was transferred to a new tube and dried under a stream of nitrogen gas until dry and then frozen (−80°C). Samples were reconstituted with 4 mL water and then run on an Agilent 6545 HPLC-quadrupole time-of-flight. Mobile phase A was HPLC water (with 0.1% formic acid) and mobile phase B was acetonitrile (with 0.1% formic acid). Upon injection, mobile phase A began at 100% followed by a gradient change to 5% mobile phase A after 21 min. Data were collected and integrated using Agilent MassHunter software. Data from integrated peaks were identified using Wiley and NIST metabolite libraries. Data were analyzed using Agilent Mass Profiler Professional for fixed effect significance (P < 0.05) and fold-change. Only those compounds (n = 156) that were statistically different, with at least a 5-fold log₁₀ abundance difference, were kept for further analyses. Identified compounds (n = 87) were analyzed using MetaboAnalyst software for pathway analyses.

Results: Partial least squares discriminant analyses segregated the metabolome from each finishing treatment and cluster analyses correctly predicting 80% of feedlot and 91% of grazed metabolomes. Of the 87 annotated compounds, taurine and hypotaurine metabolism was most highly impacted by the measured metabolome. Taurine is a naturally occurring sulfur-containing amino acid found in abundance in various tissues in the body. Studies have shown that taurine protects against mitochondrial defects often found in aging and various mitochondrial diseases.

Conclusion: Metabolomic analyses in lambs fed different finishing diets that result in significantly different days of age at harvest impacts mitochondrial function and may hold the key to determining damage due to animal age.

Funding Source: Funding was provided by the Bair Ranch Foundation.

Keywords: finishing systems, lamb, meat quality, metabolomics

93 RELATIONSHIP BETWEEN MICROBIAL GROWTH AND DISCOLORATION OF STEAKS FROM BEEF LONGISSIMUS LUMBORUM AND PSOAS MAJOR MUSCLES

M. E. Holloway^1,*, C. L. Smith¹, I. Geornaras¹, M. N. Nair¹, ¹Department of Animal Sciences, Colorado State University, Fort Collins, Colorado, United States *maggie.holloway@colostate.edu

Objectives: The relationship between microbial growth and meat color is not fully understood, and previous research has shown that microbial growth may impact the color stability of beef muscle cuts during retail display. Additionally, steaks from different beef muscles, such as the color-stable longissimus lumborum (LL) and color-labile psoas major (PM) muscles, are known to discolor at different rates. The objective of this study was to examine the relationship between the discoloration of these muscles during retail display and microbial spoilage.

Materials and Methods: Ten (n = 10) USDA Select beef LL and PM muscles were decontaminated to reduce levels of natural microflora, fabricated into 1.27-cm steaks, and then inoculated (ca. 4 log CFU/cm²) with a mixture of 6 spoilage bacteria. The steaks were wrapped in oxygen-permeable polyvinyl chloride film (PVC) on foam trays and displayed in a retail display case (3°C) under fluorescent lighting for up to 8 d. One steak per muscle was evaluated daily for instrumental color (L*, a*, and b*), percentage discoloration, and aerobic plate counts (APC; log CFU/cm²). Instrumental color was measured using a HunterLab miniscan, and 6 to 8 trained panelists evaluated percentage discoloration on a 1% to 100% continuous scale. Using the emmeans package, means were obtained for a*, percentage discoloration, and microbial counts and were plotted using ggplot2. Based on previous research, the thresholds were set at 14.5 for a* value, 20% for percentage discoloration, and 7 log CFU/cm² for APC, and the day at which the threshold was achieved was estimated.

Results: Steaks from the LL muscle went below the a* value of 14.5 by day 8 and above the discoloration threshold by day 6. On the other hand, steaks from the PM muscle went below the a* value of 14.5 by day 6 and had at least 20% discoloration by day 5. The microbial counts were at or above 7 log CFU/cm² (microbial spoilage threshold) by days 6 and 5 for LL and PM steaks, respectively.

Conclusion: Under the conditions examined in this study, both LL and PM steaks went above the discoloration threshold approximately at the same time as the microbial load reached 7 log units or above. Moreover, the redness (a* value) went below the threshold after the microbial spoilage threshold was reached. Further studies exploring the relationship between microbial growth and meat color under different conditions will provide valuable information on the interaction between the two.

Keywords: beef, discoloration, meat color, microbial spoilage

94 EVALUATION OF MODIFIED FRESH AND FROZEN LAMB LOIN CHOPS ON PALATABILITY TRAITS AND MEAT QUALITY ATTRIBUTES

T. M. Dieball^1,*, E. S. Beyer¹, G. E. Huber¹, K. M. Gundersen¹, K. R. Maddock Carlin¹, T. W. Hoffman¹, ¹Animal Science, North Dakota State University, Fargo, North Dakota, United States *taylor.dieball@ndus.edu

Objectives: The United States lamb supply chain aims to offer fresh lamb for consumers year-round. However, seasonality produces changes in supply and therefore creates challenges in cold storage. There is minimal research on how different cold chain management strategies can impact palatability. Therefore, the objectives of this study were to determine the impact of two cold chain management strategies on palatability traits, shelf life, objective tenderness, and water-holding capacity on lamb chops.

Materials and Methods: Bone-In lamb loins (N = 60) were harvested in Colorado, fabricated in New Jersey, and shipped to North Dakota State University. Upon arrival, loins were split longitudinally and assigned a treatment from modified fresh (MF) or frozen (F). The MF samples were held using proprietary methods while the F samples were immediately frozen and held at −20°C. All treatments were held in their respective cold storage units for 76 d before being thawed (if applicable), fabricated into 2.54-cm chops and assigned one of the following designations: consumer panels (3), shear force, shelf life, and drip loss. The samples were used for all assays within 48 h of thawing. The drip loss chop had a 22 to 27 g sample removed, weighed and hung by a paper clip inside a Whirlpak bag and left at 4°C for 24 h. The chop assigned to shelf life was immediately overwrapped and placed in a retail coffin case. Objective L*, a*, b* measurements were taken every 24 h for 8 d. The consumer sensory panel samples were cooked to an internal peak temperature of 71°C monitored using a Thermapen. Each panelist (N = 69) was asked to evaluate 6 samples, 3 from each treatment, for juiciness, tenderness, flavor, and overall liking while determining if each sample was acceptable for each trait. Each attribute was measured on a 100 mm line scale, with anchors at 0 (extremely dislike) and 100 (like extremely). The following day, two chops per sample were sheared for shear force using a Warner-Brazler shear force (WBSF) machine utilizing the methods from the AMSA sensory guidelines. Samples were weighed before and after cooking to determine cook loss.

Results: Consumers found the MF samples to be juicier (P < 0.05) than their F counterpart, but no other palatability differences were found (P > 0.05). There were no differences (P > 0.05) in the shear force values or cook loss percentages between F and MF samples. Similar to the sensory results, the MF samples were found to have less (P < 0.05) drip loss compared to F samples. There was an interaction between day and treatment for the shelf-life study (P < 0.05). On day 0–3 of shelf life, the MF treatment resulted in higher (P < 0.05) L* values, but days 4–7 did not differ (P > 0.05) when compared to the F treatment. Lastly, on day 1–6, the F samples had higher (P < 0.05) a* values; however, days 0 and 7 resulted in similar values between treatments (P > 0.05).

Conclusion: The MF treatment resulted in juicier samples with less drip loss, but the improvement in juiciness did not impact overall liking. However, the F samples resulted in higher color stability and a longer shelf life. These results indicate that freezing or holding lamb at a modified fresh environment does not impact overall palatability but could impact shelf life. These results can help lamb processors make more educated decisions on cold chain management strategies.

Funding Source: Funded by the American Lamb Board.

Keywords: consumer, fresh vs. frozen, lamb, palatability, shelf life

95 VISUALIZATION OF PERCENTAGE INTRAMUSCULAR FAT AND ASSOCIATION TO USDA MARBLING SCORES IN BEEF CARCASSES

R. T. Heitschmidt^1,*, M. E. Eckhardt¹, L. W. Lucherk¹, T. E. Schwartz¹, T. E. Lawrence¹, ¹Agriculture, West Texas A&M University, Canyon, Texas, United States *rtheitschmidt1@buffs.wtamu.edu

Objectives: Percentage intramuscular fat (IMF) is a chemical quantification of lipids within muscle. Muscle food scientists have reported the strong relationship between percentage IMF and respective marbling scores of beef carcasses. Our objectives were to 1) summarize and establish a historical correlation between percentage IMF and visual grading methods, and 2) capture marbling images representing percentage IMF increment values ranging from 1% to 15%.

Materials and Methods: Data from 11 sources were assimilated (n = 2,695 total carcasses) and weighted according to the respective number of carcasses used in each study (n = 12 to 718), to equalize outcomes on a per animal basis. Historical percentage IMF was reported to have been determined via AOAC 960.39 crude fat ether extract (45.5% of samples), AOCS Ba 3-38 petroleum reagent ether extract (36.4% of samples), AOCS AM 5-04 high-temperature solvent extraction (9% of samples), and AOAC 985.14 nuclear magnetic resonance (9% of samples). Linear regression models (weighted and unweighted) were developed that represent the cumulative percentage IMF to marbling score linear relationship; the equation utilized a three-digit marbling score input. Using the weighted cumulative percentage IMF-marbling linear regression equation, marbling scores were identified for each whole 1% percentage IMF increment (1%–15%). High-resolution photographs of the transverse cut surface of the M. longissimus thoracis were obtained and cropped to resemble the official USDA marbling photographs for each percentage IMF increment.

Results: Weighted average regression analysis indicated that percentage IMF can be estimated from a visual marbling score (MS) using the following equation: Percentage IMF = (MS × 0.01537) − 1.9326. The corresponding marbling score associated with each percentage IMF was as follows: 1% = Practically Devoid⁹⁰, 2% = Traces⁵⁵, 3% = Slight²⁰, 4% = Slight⁸⁵, 5% = Small⁴⁰, 6% = Modest¹⁵, 7% = Modest⁸⁰, 8% = Moderate⁴⁵, 9% = Slightly Abundant¹⁰, 10% = Slightly Abundant⁷⁵, 11% = Moderately Abundant⁴⁰, 12% = Abundant⁰⁵, 13% = Abundant⁷⁰, 14% = Very Abundant³⁵, 15% = Very Abundant¹⁰⁰. Marbling scores representing each image were determined by an E+V Beef Grading Camera and used within a deviation of ± 5 degrees of marbling.

Conclusion: This study provides baseline insight into the historical relationship between percentage IMF and marbling scores, which can be useful in further industry research on this topic. Percentage IMF may provide a more meaningful quantification of beef quality in carcasses throughout the continuum present in beef.

Funding Source: West Texas A&M University Beef Carcass Research Center

Keywords: beef, camera grading, intramuscular, marbling, quality

96 EFFECT OF XANTHAN GUM ON RHEOLOGICAL AND SENSORY PROPERTIES OF GLUTEN-FREE CHICKEN NUGGET BATTERS

E. Little^1,*, S. Smith¹, M. Bishop¹, C. Fornes¹, M. Mosby¹, L. Zaldivar¹, Z. Molloy¹, G. Tang¹, W. Schilling¹, X. Zhang¹, L. Chatham¹, ¹Food Science, Nutrition, and Health Promotion, Mississippi State University, Starkville, Mississippi, United States *eml317@msstate.edu

Objectives: With the prevalence of celiac disease, an autoimmune disease which affects about 1% of the world’s population, the demand for gluten-free products has increased. The purpose of this study was to assess the effect of xanthan gum (XG) on the rheological and sensory quality of rice (RF) and chickpea (CP) flour-based gluten-free chicken nugget batters when compared to a control batter made with gluten-containing wheat flour (WF).

Materials and Methods: A 3 × 4 factorial arrangement within a randomized complete block (RCB) design and 3 replications was used to evaluate the rheological properties of batters as affected by type of flour (wheat, rice, and chickpea) and XG concentration (0%, 0.05%, 0.075%, 0.1%). Rheological measurements were used to determine flow and viscoelastic behavior of batter treatments using a controlled-stress rheometer that was equipped with a refrigerated heat circulator. The chicken nuggets that were formulated for this experiment consisted of ground chicken, eggs, starch, and spices, along with RF, CP, or WF. These ingredients were mixed by hand, shaped into 20 g oval nuggets, and frozen overnight at −20°C. After coating the nuggets in their respective flour batter treatments, they were briefly fried at 185°C for 45 s, followed by refreezing at −20°C. Before serving, frozen nuggets were fried again at 185°C for approximately 4.5 min until reaching an internal temperature of 74°C. A 3 × 2 factorial arrangement within a RCB design with 3 replications was used to evaluate the impact of flour type and XG (0% and 0.075%) on the descriptive sensory attributes of chicken nuggets using a trained panel (n = 6–8) following the protocol IRB-23-550. Consumer panels were also conducted (n = 145), where panelists were presented with nuggets that were coated with RF, CP, and WF batters at 0.075% XG and asked to evaluate overall liking in terms of appearance, aroma, texture, flavor, and overall acceptability.

Results: The viscosity of RF batters was not impacted (P > 0.05) by the addition of XG. The addition of 0.075% XG increased (P < 0.05) the viscosity of both WF and CP batters. For descriptive analysis, there was no flour × XG interaction effects (P > 0.05) for all attributes that were evaluated. When averaged over XG concentrations, RF and CP batter-coated nuggets were not different (P < 0.05) from WF batter-coated nuggets with respect to firmness, overall juiciness, coating crunchiness, mouthcoating profile, brothy, and basic tastes including chickeny/meaty, umami, and saltiness. RF nuggets were more (P < 0.05) fracturable compared to wheat and CP nuggets. CP nuggets were less (P < 0.05) springy and more (P < 0.05) earthy, beany, and nutty than WF nuggets but were still acceptable. Consumers revealed both RF and CP nuggets did not differ in acceptability (P > 0.05) when compared to WF nuggets with respect to appearance, aroma, texture, and overall acceptability. RF nugget flavor was preferred (P < 0.05) over the WF nuggets.

Conclusion: Incorporating XG into gluten-free batters can produce viscosity levels comparable to gluten-containing batters. Chicken nuggets coated with gluten-free RF and CP batters exhibited sensory attributes comparable to those of gluten-containing WF-coated nuggets. These findings suggest that gluten-free rice and chickpea flour can serve as viable alternatives to gluten-containing WF in batters for chicken nuggets.

Funding Source: Funded by Mississippi State University’s Office of Undergraduate Research and Creative Discovery.

Keywords: None

97 IDENTIFICATION OF BACTERIAL SPECIES COMPOSITION AND DIVERSITY OF CHICKEN BREAST MEAT DURING PROCESSING

L. Zaldivar^1,*, X. Zhang¹, D. Lesak¹, G. Tang¹, S. Smith¹, C.-Y. Hsu², L. Zhang³, M. Arick², W. Schilling¹, ¹Food Science, Nutrition and Health Promotion, ²Institute for Genomics, Biocomputing & Biotechnology, ³Poultry Science, Mississippi State University, Starkville, Mississippi, United States *Lrz10@msstate.edu

Objectives: Spoilage of poultry meat is primarily caused by bacteria that survive the processing phase and sequentially multiply during storage. Understanding the bacterial profile of chicken during processing is crucial for determining which bacteria survived the processing and whether they contribute to chicken spoilage during storage. Through advanced methods like Oxford nanopore amplicon sequencing, specific bacteria on chicken meat after processing can be identified at the species level. The objective of this study was to characterize the composition and diversity of bacteria on fresh chicken breast meat during poultry processing, from slaughter to packaging.

Materials and Methods: Eight chicken breast samples (n = 8/step) from 8-wk-old broilers were collected at 5 different processing steps (before antimicrobial wash, after antimicrobial wash/pre-chill, post-chill, post-deboning, and pre-packaging) from a poultry processing plant on 3 separate occasions (block). A randomized complete block design with 3 replications was used to evaluate the differences in microbial counts, microbial composition, and relative abundance among 5 processing steps. The samples were swabbed with sterile sponges and stomached insterile buffered peptone water. The resulting homogenate filtrate was used for enumeration of bacteria, and the pellet was collected for microbial genomic DNA extraction. The full-length 16S rRNA was amplified from each sample and individually barcoded, and the barcoded amplicon libraries were sequenced on MinION R10.4.1 flow cells.

Results: The processing successfully reduced the counts of aerobic bacteria, E. coli, coliform, and lactic acid bacteria (LAB). In comparison to step 3 (post-chill), coliform and LAB counts increased (P < 0.05) after step 4 (post-deboning), followed by a subsequent decrease (P < 0.05) after step 5, likely attributed to human interaction during deboning. Samples from steps 3 and 5 exhibited a decrease (P < 0.05) in alpha diversity (Chao1) compared to steps 1 and 4. The reduction in bacterial counts and diversity was attributed to the chilling process at step 3 and the final PAA (peroxyacetic acid) washing before step 5. Utilizing nanopore sequencing approach, we successfully classified bacteria down to the species level. After sequencing, a total of 11,672,066 reads were generated from 120 samples, and a total of 4,951 bacterial species were detected. Notably, throughout the processing stages, 3 thermophilic bacteria, Anoxybacillus contaminants, Neobacillus thermocopriae, and Anoxybacillus flavithermus, emerged as the top 3 most predominant species found on chicken breast. Pseudomonas was not detected by traditional plating methods, but multiple species were identified by nanopore sequencing, indicating a necessity for a molecular bacterial detection method and a potential risk of chicken breast spoilage from these Pseudomonas bacteria during refrigerated storage.

Conclusion: The antimicrobial interventions in the poultry processing line did not completely eradicate various bacteria, although they reduced overall bacterial counts significantly. Therefore, it is recommended to implement molecular bacterial detection methods alongside traditional plating methods. This approach provides a more thorough understanding of the bacterial population on chicken breast and could potentially improve processing practices to ensure product quality and safety.

Keywords: bacteria, DNA, nanopore, poultry, spoilage

98 EFFECTS OF AMMONIA STRESS ON THE GROWTH PERFORMANCE AND FILLET QUALITY OF CHANNEL AND HYBRID CATFISH

G. Tang^1,*, X. Zhang¹, S. W. Smith¹, E. M. Little¹, L. R. Zaldivar¹, Z. M. Molloy¹, H. Tamut², P. Allen², L. Zhang³, B. Ott⁴, C. Older⁴, G. Waldbieser⁴, M. W. Schilling¹, ¹Department of Food Science, Nutrition, and Health Promotion, ²Department of Wildlife, Fishers and Aquaculture, ³Department of Poultry Science, Mississippi State University, Starkville, Mississippi, United States, ⁴Warmwater Aquaculture Research Unit, USDA, Stoneville, Mississippi, United States *gt467@msstate.edu

Objectives: Cultivated catfish is the largest sector of the United States aquaculture industry. High concentration of ammonia in pond water is caused by fish excretion and decomposition of feces, uneaten feed, and phytoplankton. This can contribute to reduced catfish production and decreased fillet quality. Therefore, the objective of this study was to investigate the growth performance and fillet quality of cultivated channel (Ictalurus punctatus) and hybrid (♂I. furcatus × ♀ I. punctatus) catfish under ammonia stress.

Materials and Methods: Catfish (n = 240) were raised in 200-L tanks at two separate occasions. During each occasion, each tank (n = 30 fish, 99–166 g) was randomly assigned to one of the following 4 treatments: channel catfish control (CC), channel catfish under high ammonia stress (CA), hybrid catfish control (HC), and hybrid catfish under high ammonia stress (HA). Control tanks targeted 1 mg/L total ammonia and 18 μg/L unionized ammonia concentration. High ammonia stress tanks targeted 15 mg/L total ammonia and 200 μg/L unionized ammonia concentration. Fish were harvested after a 5-wk grow-out period. A split-plot arrangement in a randomized complete block design, with 2 replications (occasions), was conducted to determine the impact of ammonia stress on the weight and length gain (n = 30/treatment), fillet pH and color (n = 12/treatment), and fillet sensory quality (n = 6 panelists) of channel and hybrid catfish. Blood and intestinal content were collected for further analysis.

Results: Both the fish species (P < 0.05) and ammonia level (P < 0.05) impacted catfish weight and length gain. Specifically, the weight gain of CC (186 g) was greater (P < 0.05) than the other 3 treatments. Although CA (111 g) and HC (115 g) were not different (P > 0.05) in weight gain, they were both greater (P < 0.05) than HA (65 g). Regarding length gain, CC (54 mm) exhibited greater (P < 0.05) length gain than HA (32 mm); no other differences existed (P > 0.05). Descriptive sensory analysis of baked catfish fillets indicated that HA had a more intense sulfur aroma (P < 0.05) than CA and a more intense ammonia aroma (P < 0.05) than CC (P < 0.05). HC had a grassier aroma (P < 0.05) than other treatments. In addition, CA smelled less fishy (P < 0.05) than the hybrid treatments. With respect to flavor, HC was more earthy (P < 0.05) than all other treatments, and more bitter (P < 0.05) than CA. No differences (P > 0.05) were observed among all 4 samples (CC, CA, HC, HA) in terms of fishy, ammonia, and sulfur flavors, salty and umami taste, juiciness, or astringent aftertaste. The fillet pH did not differ (P > 0.05) among all 4 samples. Regarding instrumental color (L*, a*, b*), hybrid catfish were redder (P < 0.05) and more yellow (P < 0.05) than channel catfish.

Conclusion: Ammonia stress reduced the weight gain of catfish, indicating compromised growth, although it had minimal impact on sensory quality. High ammonia negatively affected the growth of hybrid catfish more than channel catfish. Further research will be conducted to determine the microbial composition and diversity in the catfish gut, with the goals of elucidating the underlying mechanisms for the observed changes in catfish performance and relationship to fish health.

Funding Source: USDA-ARS sponsored project of the MS Center for Enhancing Utilization and Safety of Catfish and Other Aquatic Foods.

Keywords: ammonia stress, catfish growth rate, fillet quality, sensory analysis

99 EFFECT OF RUBAIYAT GRAPE SKIN EXTRACT ON COLOR AND LIPID OXIDATION OF GROUND BEEF PATTIES

W. McCune^1,*, R. Ramanathan¹, G. Mafi¹, M. Pfeiffer¹, W. McGlynn¹, M. Scott¹, N. Jewell¹, ¹Animal and Food Sciences, Oklahoma State University, Stillwater, Oklahoma, United States *noah.jewell@okstate.edu

Objectives: Ground beef is a highly perishable meat product and accounts for 40% of total retail beef marketed in the US. Various studies have utilized antioxidant and packaging technologies to enhance the shelf-life of ground beef. Rubaiyat grapes are a novel hybrid variety with a more intense color than traditional grape varieties. Grape skin is rich in antioxidants such as phenolic compounds and has the potential to minimize oxidative changes. However, limited knowledge is available on the impact of Rubaiyat grape skin extract on ground beef color and lipid oxidation. The objective was to evaluate the effects of Rubaiyat grape skin extract on ground beef patties quality under retail display conditions.

Materials and Methods: Three beef chuck rolls were purchased from a local commercial retailer. Chuck rolls were coarse ground prior to the addition of extract. The antioxidants in grape skin were extracted in water via the boiling method. In addition, oil-in-water emulsion of grape skin extract was also prepared. Various antioxidant treatments include control (C; without the addition of any antioxidants), control emulsion (oil, water, and emulsifier), grape skin extract (GS), grape skin emulsion (oil, water grape skin extract, and emulsifier), and rosemary (R; commercially used natural antioxidant). Samples containing CE, GS, and GSE were mixed at 1.5% to coarse ground beef, while rosemary was added at 0.2% (based on provider recommendation). Antioxidants were hand-mixed for 3 min and fine ground. 100 g patties (n = 3) were weighed and formed by hand using a KitchenArt Adjust-A-Burger Press. Patties were placed onto Styrofoam® trays with soaker pads, overwrapped with polyvinyl chloride film, and placed in a simulated retail display (1,600 lux) for 2 d. The surface color was measured daily using a HunterLab MiniScan spectrophotometer. The surface color change was measured as L*, a*, and chroma. Lipid oxidation was measured as thiobarbituric acid reactive substances (TBARS) values. The experiment was replicated 3 times (n = 3). The data were analyzed using the GLM procedure of SAS and considered significant at P < 0.05.

Results: A treatment × day interaction (P < 0.05) resulted for a* and chroma values. Patties with GSE and R treatments had significantly greater (P < 0.05) a* values (redness) and chroma values compared to patties with CE and GS after 2 d of storage. The main effect of antioxidant addition (P < 0.05) was significant for L* values. The emulsion control patties were lighter (P < 0.05) in color than the control without any antioxidant addition. Only the main effects of storage time and antioxidant treatment were significant for lipid oxidation. Rosemary decreased lipid oxidation (P < 0.05) compared with other antioxidant treatments. There were no differences (P > 0.05) between control and grape skin antioxidant treatments. However, grape skin emulsion had numerically lower lipid oxidation than grape skin water emulsion and emulsion control. The commercially available rosemary is more concentrated; hence, increasing the concentration of Rubaiyat extracts might provide antioxidant benefits.

Conclusion: The current study suggests that the addition of grape skin emulsion has a beneficial effect on preserving color, while there was no significant effect on lipid oxidation. Conducting a taste panel and concentrating grape skin extract will help to standardize its potential application in the meat industry.

Keywords: antioxidant, beef color, ground beef, lipid oxidation

100 CONSUMER SIMULATED STORAGE CONDITIONS FURTHER DECREASE MEAT QUALITY IN DIFFERENTIALLY FROZEN/THAWED BEEF RIB PRIMALS

C. D. Stafford^1,*, M. J. Taylor¹, M. A. Alruzzi¹, T. R. Bird¹, S. K. Matarneh¹, ¹NDFS, Utah State University, Logan, Utah, United States *chandler.stafford1@gmail.com

Objectives: Freezing is a commonly used preservation method in the meat industry to prevent spoilage and deterioration. Subjecting meat to freezing temperatures causes the water within to form ice crystals of various shapes and sizes. The growth of these crystals is primarily determined by the rate of freezing and has been shown to negatively impact many quality traits, including color, juiciness, and yield. Whole beef rib primals may be susceptible to these detrimental changes following freezing; however, the impacts of different freezing/thawing conditions have not been thoroughly evaluated. Additionally, retail steaks obtained from previously frozen primals would likely undergo a second freeze/thaw cycle as consumers commonly freeze retail cuts upon purchase. This may further influence beef quality before consumption. Therefore, the objective of this study was to investigate the effect of an additional freezing/thawing cycle on the quality of beef steaks originating from rib primals that had undergone different freezing/thawing treatments beforehand.

Materials and Methods: Forty rib primals were purchased from a local beef harvesting facility 48 h postmortem. Eight were designated as controls (untreated), 16 were frozen at −20°C, while the remaining 16 were frozen at −80°C. After storing for 12 wk in their respective freezing treatment, 8 ribs from each condition underwent either slow (refrigerator) or rapid thawing (water submersion), resulting in 5 different treatment groups: control, fast freezing/fast thawing (FF), fast freezing/slow thawing (FS), slow freezing/fast thawing (SF), and slow freezing/slow thawing (SS). Control ribs were fabricated and evaluated immediately upon arrival (unaged), while treated ribs were fabricated after thawing. Steaks from the cranial, medial, and caudal locations were obtained and used for evaluation. Additional steaks from each location were vacuum sealed and frozen a second time at −20°C, stored for 4 wk, and then thawed in a refrigerator to simulate consumer conditions. Samples from both cycles were evaluated for tenderness, color, drip loss, and ultrastructural changes, and values obtained from the 3 sampling locations were averaged for each rib. Data were analyzed using a mixed model of SAS, and Tukey-Kramer multiple comparisons test was performed. Significance was considered at P ≤ 0.05.

Results: In general, the first freezing/thawing cycle, regardless of the treatment, increased tenderness, a*, b*, and drip loss compared to the control (P < 0.05), with notable degradation observed in ultrastructural micrographs. Interestingly, the FF and SF treatments elicited less drip loss (P < 0.05) than the FS and SS. The consumer simulation cycle further influenced meat quality by decreasing a* and b* (P < 0.05), increasing tenderness (P < 0.05), and accentuating ultrastructural deterioration.

Conclusion: Multiple freezing/thawing cycles increased tenderness but negatively impacted color and water-holding capacity. While minimal differences between freezing conditions were detected, fast thawing may be favorable for reducing water loss. Overall, consumers should be aware of the freezing/thawing conditions and the number of freeze/thaw cycles their beef has undergone to maintain optimal quality.

Funding Source: National Cattleman’s Beef Association

Keywords: beef rib primals, electron microscopy, freezing/thawing rates, meat quality, sampling location

101 LUBABEGRON’S EFFECT ON TRAINED PANELIST EVALUATION AND FATTY ACID CONCENTRATIONS OF HOLSTEIN STEERS

L. K. Decker^1,*, R. P. Wagner¹, T. M. Hays¹, J. F. Legako¹, D. R. Woerner¹, P. J. Rincker², W. C. Kayser², ¹Animal and Food Sciences, Texas Tech University, Lubbock, Texas, United States, ²Animal Health, Elanco, Greenfield, Indiana, United States *lidecker@ttu.edu

Objectives: Lubabegron fumarate (LUB) is the newest β-agonist approved for use in fed cattle, labeled for reduction of ammonia emissions. While its use is widespread in feedlot cattle, there has been minimal research conducted to evaluate its effects on meat quality. Therefore, the study’s objective is to understand the effect of LUB on sensory evaluation and fatty acid concentration in Holstein steers.

Materials and Methods: Holstein steers not fed a β-agonist and those treated with lubabegron for 28 (LUB28), 56 (LUB56), or 84 d (LUB84) prior to slaughter were identified. Strip loins (n = 212)were collected from identified carcasses, ranging in quality grade from USDA Select to USDA Prime. At 7 d postmortem, loins were fabricated into 2.54 cm steaks and 2 steaks were randomly assigned to each of the following aging periods: 7, 14, 21, 28, or 35 d postmortem, then frozen until analysis. Steaks for sensory evaluation were selected only from the samples with marbling scores frommodest 00 to moderate 99, and fatty acid analysis was performed on steaks with marbling scores from small 00 to 99. For sensory evaluation, steaks were cooked in a combi-oven at 204° C on a grill grate, with a target peak temperature of 71°C. Attributes evaluated were as follows: beef flavor, tenderness juiciness, browned, roasted, fat-like, umami, buttery, oxidized, liver, metallic, and sour. Samples were rated on a 100-point scale with 0 = dry/tough/not detectable and 100 = extremely juicy/tender/intense. Fatty acids methyl esters were extracted from raw steaks in an aqueous solution and quantified utilizing gas chromatography–flame ionization detection. The trained panelist and fatty acid data were analyzed as a split-plot design, with treatment serving as a main plot factor and age serving as a subplot factor. Peak temperature was utilized as a covariate in trained sensory analysis. A 2-way anova was performed for fatty acid concentration analysis by treatment. Moreover, a principal component analysis (PCA) was performed withthe total concentration of saturated (SFA), monounsaturated (MUFA), and polyunsaturated (PUFA) fatty acids, thencolored by treatment.

Results: There were no interactions (P ≥ 0.72) between treatment and aging time for any sensory attribute. Also, there were no differences (P ≥ 0.12) among treatments for juiciness, beef flavor ID, roasted, browned, fat-like, buttery, umami, metallic, oxidized, liver-like, or sour. Control samples were more tender (P = 0.02) than LUB84. Samples aged 28 and 35 d were more tender (P =0.03) than samples aged 7 d. Moreover, samples aged 35 d were rated higher (P < 0.01) for oxidized flavor than samples aged 7 and 14 d. Similarly, 35 d-aged samples were rated higher (P < 0.01) for liver-like and sour flavors in comparison to 7, 14, and 21 d samples. Total fatty acid concentration was not different among treatments (P = 0.07). Total concentrations of MUFA, PUFA, and SFA were not different(P > 0.12) among treatment or aging periods. PCA accounted for 92.5% of the total variation among samples; however, there were no discernable patterns among treatments.

Conclusion: LUB had minimal impacts on eating quality when standardized by quality grade. However, there is previous evidence that LUB negatively impacted marbling score, and thus quality grade, which is a driver of palatability and requires further research to understand its impact on eating quality.

Funding Source: Funded in part by Elanco Animal Health.

Keywords: beef, fatty acids, meat quality, sensory evaluation, trained panel

102 INFLUENCE OF BY-O-REG+ BEEF INCLUSION ON GROWTH PERFORMANCE, CARCASS TRAITS, AND MEAT QUALITY OF BEEF STEERS

B. DeBruin^1,*, C. Bakker¹, J. K. Grubbs¹, K. Underwood¹, W. Rusche¹, Z. Smith¹, A. Blair¹, ¹Department of Animal Science, South Dakota State University, Brookings, South Dakota, United States *bergin.debruin@sdstate.edu

Objectives: The study objective was to determine the influence of an oregano-based essential oil additive (By-O-Reg+ Beef) on growth performance, carcass traits, and meat quality characteristics of steers.

Materials and Methods: Yearling steers [n = 128, initial body weight (BW) = 335 ± 7.98 kg] were allotted to 16 pens (n = 8 pens per treatment with 8 steers per pen). Steers were blocked by initial BW grouping in a Randomized Complete Block Design (n = 8 blocks total). Treatments included 1) control group fed no oregano-based essential oil (CON) and 2) group fed 4 g/steer daily of By-O-Reg+ Beef (Advanced Ag Products, Canton, SD; OEO). Steers were transitioned to a diet that contained 90% concentrate over 14 d and remained on the finishing diet until harvest on d 149. Steers were shipped for harvest on 3 trucks (both groups were represented on each truck) when they reached a common compositional endpoint. Prior to chilling hot carcass weights (HCW) and liver scores were recorded. Following chilling, ribeye area, 12^th rib backfat thickness, marbling score, USDA Quality grade, USDA Yield grade, and instrumental color (L*, a*, b*) were recorded. Strip loins were collected from a subsample of carcasses (n = 62). Purge loss and pH were recorded for each strip loin prior to fabrication into 2.54-cm steaks. One steak was overwrapped with a high oxygen permeable film and placed under a simulated retail display for 10 d for evaluation of objective color (L*, a*, b*) using a handheld colorimeter. Color score and discoloration were evaluated by a trained panel once daily (days 0–10). Four steaks were vacuum packaged and aged for 4, 7, 14 or 21 d for Warner-Bratzler Shear Force (WBSF) analysis. Carcass traits, purge loss, pH, and initial L* a* b* were analyzed as a randomized complete block design using mixed model procedures of SAS with pen included as the experimental unit. The model included fixed effect of dietary treatment and random effect of block (pen location). Retail display and WBSF data were analyzed as repeated measures using the compound symmetry covariance structure for the effects of treatment, aging or display day, and their interactions. Peak temperature was included as a covariate for WBSF.

Results: Treatment did not influence (P > 0.05) growth performance, carcass traits, initial color, or purge loss. Striploins from the OEO treatment had higher pH values (P = 0.043). No treatment by day interaction (P > 0.05) was observed for objective color score or subjective color score during the retail display. Treatment did not influence (P > 0.05) objective or subjective color scores; however, L* values increased (P = 0.0003) from day 0 to day 10, while a* values and b* values decreased (P < 0.0001) during the display period. Similarly, subjective color scores increased (P < 0.0001) indicating samples became darker during the display period. A treatment by day interaction (P = 0.095) was detected for discoloration scores. Steaks from the OEO treatment tended to appear less discolored from day 2 to day 10 than CON steaks. There was no treatment by day interaction observed (P > 0.05) for WBSF values, however, values decreased (P < 0.0001) over the aging period.

Conclusion: Data indicate that the inclusion of an oregano essential oil has limited impact on the growth performance and carcass traits of steers. However, inclusion tended to reduce discoloration during retail display suggesting a role in shelf stability.

Funding Source: This research was supported by state and federal funds appropriated to South Dakota State University including support from the South Dakota State University Agriculture Experiment Station, USDA National Institute of Food and Agriculture through the Hatch Act (Accession #1020088), and by Advanced Ag Products, Canton, SD (Grant #3P3168).

Keywords: beef, carcass traits, color, essential oil, meat quality

103 EFFECT OF NOVEL-ENVIRONMENT STRESS ON MEAT QUALITY, STEAK TENDERNESS, AND RETAIL CASE-LIFE OF BEEF DERIVED FROM BEEF × DAIRY HEIFERS

M. E. Fatola^1,*, M. V. Sorenson¹, L. D. L. C. Garcia¹, D. M. Wulf¹, ¹Animal and Comparative Biomedical Sciences, University of Arizona, Tucson, Arizona, United States *muyiwaf@arizona.edu

Objectives: Pre-harvest stress can lead to muscle glycogen reduction in beef cattle causing dark cutters. This study utilized novel-environment stress to investigate the impact of stress on meat quality, steak tenderness, and retail case-life of beef derived from beef-on-dairy heifers.

Materials and Methods: Three days prior to harvest, 306 beef × dairy heifers were randomly sorted into two groups, and one group (CON) was returned to the original pen while the second group (STRESS) was put into a new pen. On harvest day, heifers were transported 108 km by truck, rested for 1 h, and harvested at a commercial packing plant. Following a 3-d chill, carcasses were camera graded and L*a*b* measurements were taken on the exposed ribeye muscle. Longissimus samples were excised from randomly selected carcasses (n = 42 CON, n = 41 STRESS), placed in plastic zipper bags, and transported to the University of Arizona under refrigeration. All analyses were conducted on fresh, never-frozen, samples. At 6 d postmortem, ultimate pH was determined, and muscle samples were weighed, vacuum packaged, and placed in 2°C dark storage. The muscle samples were removed from vacuum packaging at 13 d postmortem, weighed to determine purge loss, and cut into two steaks each, one for retail case-life and one for shear force. Case-life steaks were placed on retail trays, wrapped with oxygen-permeable PVC film, stored at 2°C under fluorescent lighting (1,857 lux), and evaluated daily for 15 d by trained panelists for color and surface discoloration and by measuring L*a*b*. At 14 d postmortem, shear force steaks were cooked to 69°C, weighing before and after cooking to determine cooking loss, and evaluated for visual degree-of-doneness, slice shear force (5 min after cooking), and Warner-Bratzler shear force (chilled 1–2 d after cooking).

Results: The STRESS carcasses had darker ribeyes than CON carcasses, based on RGB grading camera data: R 102.4 vs 105.2, G 69.1 vs 71.1, and B 58.3 vs 59.9, as well as L*a*b* colorimeter data: L* 38.3 vs 39.6, a* 20.7 vs 21.9, and b* 8.0 vs 8.8 (P < 0.05). Based on the b* distribution of all carcasses, there was a threshold at approximately 6.5, below which carcasses were likely classified as dark cutters. A higher percentage (15.0 vs 0.8%) of STRESS carcasses had b* below 6.5 than CON carcasses (P < 0.05). Lean maturity scores were greater (A 71 vs A 59) for STRESS carcasses than for CON carcasses (P < 0.05). All other carcass characteristics did not differ between treatment groups (P > 0.05). Ultimate pH was higher (5.56 vs 5.45), purge loss was lower (1.80 vs 2.15%), and visual degree-of-doneness was lower (more “rare”) for STRESS compared to CON (P < 0.05). Cook time, cooking loss, and shear force were not affected by treatment (P > 0.05). During retail display, STRESS steaks had lower L* and panel color scores than CON steaks (P < 0.05) throughout the entire 14 d evaluation, but treatment had little to no effect on discoloration rate or length of case life (P > 0.05).

Conclusion: Stress to beef × dairy heifers resulted in steaks that had darker color, higher ultimate pH, lower purge loss, and rarer visual degree-of-doneness scores, but did not affect length of retail case life or cooked steak tenderness. Pre-harvest stress, including novel environments, should be avoided to maximize meat quality.

Keywords: beef, meat color, meat quality, novel environment, stress

104 APPLICATION OF SODIUM ACID SULFATE AS A SHORT-DURATION DIP (15-S) ON THE QUALITY OF POULTRY LEG QUARTERS TREATED OVER 28-D PERIOD

M. P. Myer^1,*, C. B. Austin², E. G. Olson², C. Ovall³, S. C. Ricke², D. K. Dittoe¹, ¹Animal Science, University of Wyoming, Laramie, Wyoming, ²Meat Science and Animal Biologics Discovery Program, Animal and Dairy Sciences, University of Wisconsin-Madison, Madison, Wisconsin, United States, ³R&D and Lab Services, Jones-Hamilton Co., Walbridge, Ohio, United States *ddittoe@uwyo.edu

Objectives: Due to the relatively short shelf-life of poultry products (7–10 d), shelf-life extension efforts are ongoing. Poultry carcasses and parts are commonly treated with short-duration antimicrobial solutions to improve shelf-life while maintaining product quality and integrity. In our previous work, we demonstrated that using sodium acid sulfate (SAS) as a short-duration dip (15 s) on poultry parts effectively improves these products’ microbial quality and safety by modulating the microbiota while extending their shelf-life. However, the subsequent product quality has yet to be validated and is necessary for industry acceptance. Therefore, the objective of the current study was to evaluate the effects of inorganic acid, SAS, commercial standard, peracetic acid (PAA), and their combination as a poultry 15-s antimicrobial dip on chicken leg quarter objective quality characteristics over a 28-d period.

Materials and Methods: Skin-on, bone-in-leg quarters (N = 300) obtained from antimicrobial-free, USDA-inspected carcasses were not treated (NT) or treated for 15 s in either tap water (TW), SAS (3%), PAA (500 ppm), or combination of SAS + PAA. Leg quarters were rested on clean baker racks (2 min), packaged in a film overlayed plastic tray, maintained at 4°C in dark storage, and sampled on d 0, 4, 7, 14, 21, and 28 of shelf-life for objective color (CIE L*, a*, b*) measurements and intramuscular pH. Quality data were analyzed as a GLM in R Studio with pairwise differences determined using Tukey’s (P ≤ 0.05).

Results: There was no interaction or main effect of antimicrobial treatment and time for L* values (P > 0.05); however, there was a main effect of treatment (P < 0.05) on a* objective color where those treated with SAS and SAS + PAA had lower a* objective color (less red) than those treated as NT but were not different than those treated with TW and PAA. There was an interaction between antimicrobial treatment and time for the b* objective color and pH of the treated leg quarters (P < 0.05). Over the first 7 d, the b* objective color (yellow) was stable and then increased from d 14 to d 28 (P < 0.05). On d 21, those treated with SAS were less yellow (b* value) than those treated with NT, TW, SAS + PAA, but not PAA. On d 28, SAS + PAA were less yellow than all other treatments (P < 0.05). Over time, the intramuscular pH of all leg quarters increased (P < 0.05). Those treated with SAS and SAS + PAA did not differ in intramuscular pH from those treated with NT or TW at any sampling time (P < 0.05).

Conclusion: When used as a short-duration antimicrobial intervention, the use of SAS alone did not result in significant differences of objective color or pH compared to the industry standard PAA. However, the whitening of the leg quarters by SAS and SAS + PAA indicated the need for a shorter duration time (5–10 s) or the use of the SAS as a spray to reduce visual differences compared to those not treated.

Funding Source: The Center for Innovative Food Technology (CIFT), in collaboration with Jones-Hamilton Co., funded the current research. Their financial support did not influence the design, execution, or results of the current work.

Keywords: objective color, pH, poultry parts, quality, sodium acid sulfate

105 INFLUENCE OF EXTENDED FROZEN STORAGE ON COLOR STABILITY AND SENSORY ATTRIBUTES OF BEEF SUBPRIMALS

T. W. Dobbins^1,*, S. Blandon¹, A. Roldan¹, K. Hanlon², T. Brown², M. X. Sanchez-Plata¹, D. R. Woerner¹, J. F. Legako¹, ¹Animal and Food Sciences, Texas Tech University, Lubbock, Texas, United States, ²Innovation Center, Cargill, Wichita, Kansas, United States *tdobbins@ttu.edu

Objectives: The primary objective of this study was to evaluate the effects of long-term freezing of beef subprimals and steaks on shelf-life, spoilage, and sensory attributes. The secondary objective of this study was to compare traditional rollstock (ROLL) packaging to nitrite-embedded (NIT) rollstock packaging.

Materials and Methods: Thirty-six strip loins and top sirloin butts were collected from USDA low Choice, “A” maturity carcasses at a commercial abattoir. After an aging period of 12 d, subprimals were allocated to a treatment: frozen as a subprimal for 180 d (SNGL), frozen as a subprimal for 90 d, thawed, fabricated into steaks, and frozen for an additional 90 d (DBL), and a fresh, never-frozen product (CON). Subprimals were fabricated into M. gluteus medius (GM) and M. Longissimus lumborum (LL), the cranial or caudal portion of the muscle was randomly assigned to packaging film and cut into 2.54 cm steaks. After predetermined storage periods, SNGL, DBL, and CON steaks were displayed in retail display for 28 d. Color was evaluated every 12 h instrumentally and visually every 24 h. Analyses of spoilage organisms, lipid oxidation and purge loss were conducted on days 0, 14, and 28. Trained sensory analyses was conducted on 0 d steaks. Color data and purge loss were analyzed using a generalized mixed linear model, while a mixed model was used to conduct other analyses with fixed effects of freezing, packaging, and display. Significance was declared at P ≤ 0.05.

Results: There was a freezing treatment × packaging × display interaction for visual redness score in the GM and LL where NIT packaging increased (P < 0.05) redness scores in all freezing treatments across all timepoints for the LL and on 0 and 14 d in the GM steaks. Visual saturation scores for GM steaks were greatest (P < 0.05) in NIT on 0 and 14 d, while NIT on d 28 was similar to ROLL on 14 and 28 d. Visual saturation scores in the LL were greatest (P < 0.05) on d 0 regardless of packaging and then NIT packaging on 14 and 28 d was similar to ROLL on 0 d. The a* values of LL and GM steaks were increased in NIT on 0 and 14 d (P < 0.05). Purge loss was greatest in DBL GM steaks on 0 and 14 d (P < 0.05). In GM steaks, initial juiciness was reduced in SNGL compared with CON and DBL (P < 0.05). Initial and sustained juiciness was reduced in the SNGL and DBL compared with CON of LL steaks (P < 0.05). Aerobic plate counts (AC) from GM steaks were decreased in the DBL frozen steaks compared with SNGL and CON (P < 0.05), while AC were decreased in DBL steaks compared with CON (P < 0.05). In GM and LL steaks, AC, Enterobacteriaceae, and lactic acid bacteria were increased on 28 d compared with 0 d (P < 0.05). In the GM steaks, there was a freezing treatment × packaging interaction where there was increased (P < 0.05) malondialdehyde (MDA) in the DBL-ROLL, SNGL-ROLL, and DBL-NIT compared with the SNGL-NIT. In LL steaks, there was a packaging × display interaction where there was an increase (P < 0.05) in MDA in the ROLL-28 compared with the nitrite packaging across all display timepoints.

Conclusion: This study showed that freezing of beef subprimals has minimal influences on descriptive sensory attributes, other than juiciness. Likewise, markers of beef color varied little due to freezing regiment after the first day of display. Finally, the use of nitrite-embedded packaging improves color performance throughout display.

Funding Source: Research coordinated by the National Cattlemen’s Beef Association, a contractor to the Beef Checkoff.

Keywords: beef, color, freezing, nitrite-embedded packaging

106 PREDICTIVE MODELS FOR LIVER ABSCESS DETECTION IN BEEF × DAIRY HEIFERS FROM SERUM CHEMISTRY AND COMPLETE BLOOD COUNTS

R. Wilson^1,*, B. J. Johnson¹, J. O. Sarturi¹, W. L. Crossland¹, K. E. Hales¹, R. J. Rathmann¹, C. L. Bratcher², R. A. Amachawadi³, T. G. Nagaraja⁴, B. A. Foraker⁵, M. E. Theurer⁶, D. R. Woerner¹, ¹Department of Animal and Food Sciences, Texas Tech University, Lubbock, Texas, United States, ²Department of Animal and Dairy Sciences, Mississippi State University, Starkville, Mississippi, United States, ³Department of Clinical Sciences, ⁴Department of Diagnostic Medicine/Pathobiology, Kansas State University, Manhattan, Kansas, United States, ⁵Department of Animal Sciences, Washington State University, Pullman, Washington, United States, ⁶Veterinary Research and Consulting Services, LLC, Hays, Kansas, United States *reese.wilson@ttu.edu

Objectives: The objective of this study was to determine the detection of liver abscesses using complete blood counts (CBC) and serum chemistry to identify blood-based biomarkers for detection of liver abscesses in feedlot cattle.

Materials and Methods: Blood samples were obtained on a subset of beef × dairy, crossbred heifers without and with liver abscesses (n = 113; n = 94, respectively) at harvest, immediately post-exsanguination. From these blood samples, CBC and serum chemistry variables related to liver health were analyzed to model the liver abscess condition. Predictive models were constructed using logistic regression and 3 machine learning algorithms, Rpart, random forest, and LogitBoost, with individual animal serving as the experimental unit. For construction of each model, data was randomly split to train models on 70% of data and the remaining 30% was used to test models. When training each algorithm, all possible combinations of CBC and serum chemistry variables were tested until the greatest accuracy was achieved.

Results: Using logistic regressions of CBC measures, only white blood cell concentration was accurate (65.85%; P < 0.01); however, it was not deemed a viable biomarker due to its low specificity (54.79%). From serum chemistry variables, no measure was accurate (P ≥ 0.44) at predicting liver abscess condition. Using machine learning algorithms, the LogitBoost model achieved the highest accuracy (80.65%; P < 0.01) and specificity (85.71%). This model used 4 CBC variables to predict liver abscess condition, white blood cells (10⁹/L), basophils (10⁹/L), red blood cell (M/μL), and procalcitonin (%). The remaining two algorithms used, random forest and Rpart, were moderately accurate (77.42%; P < 0.01). The development of an accurate blood test capable of detecting liver abscesses during the finishing phase could facilitate therapeutic interventions or alternative marketing strategies for cattle. Nevertheless, the modest accuracy observed in this study, coupled with the impracticality and cost associated with blood sample analysis, may render it unfeasible. Nevertheless, the key blood chemistry variables identified in cattle with abscessed livers indicate an immune response.

Conclusion: No single variable was capable of predicting liver abscess presence, but multivariate predictive models showed potential predicting power based on blood chemistry. The results of this study warrant further investigation for biomarkers of the liver abscess condition. Developing an antemortem indicator for liver abscesses could offer valuable insights for management decisions and research endeavors, especially in assessing intervention strategies.

Funding Source: The project was funded, in part, by the USDA-FFAR International Consortium for Antimicrobial Stewardship in Agriculture (ICASA).

Keywords: beef-dairy, blood-based biomarker, composite, liver abscess, machine learning

107 INFLUENCE OF HEAT MITIGATION STRATEGIES IN SOUTHERN BEEF FINISHING SYSTEMS ON CARCASS AND MEAT QUALITY ATTRIBUTES

J. N. Proctor^1,*, A. M. Stelzleni¹, C. T. Lee¹, M. J. Nawaz¹, C. C. Catrett¹, ¹Animal & Dairy Science, University of Georgia, Athens, Georgia, United States *jnp86187@uga.edu

Objectives: Heat stress can have a significant impact on finishing cattle, which is one of the main reasons cattle feedlot operations in the American southeast are sparse. Therefore, the objective of this study was to determine the effects of heat mitigation techniques for beef finishing systems in the Southern US on carcass and meat characteristics.

Materials and Methods: Sixty Angus crossbred steers (374 ± 57 kg) were stratified by weight then randomly assigned to one of 4 finishing environments: covered finishing barn with fans (CWF), covered finishing barn without fans (CNF), outside with shade (SHD), and outside without shade (OUT). Steers had ad libitum access to a typical feedlot ration and water. Once each treatment reached average target weight (590 kg), that treatment group was slaughtered, and carcass data were collected 24 h postmortem. Striploins were removed from the right side of each carcass after data collection and fabricated anterior to posterior into nine steaks (2.54 cm). AUTHOR: As meant?The first steak was designated, vacuum packaged, and frozen for proximate analysis. The following 3 steaks vacuum packaged, and randomly assigned to aging (7, 14, or 21 d; 2 ± 1°C) for slice shear force analysis. The remaining 5 steaks were designated for a 7-d simulated retail display objective and subjective color panel. Color display steaks were randomly assigned 0, 1, 3, 5, or 7 d of display, placed in Styrofoam trays with PVC overwrap, and placed in retail display cases (1 ± 2°C). Trained subjective color panelists assigned steaks scores for color, worst point color, and percent discoloration. Objective color L*, a*, b*, and isosbestic wavelengths were recorded daily (±2 h). Hue, chroma, ΔE, deoxymyoglobin, oxymyoglobin, and metmyoglobin were calculated. Data were analyzed as a completely randomized design (SAS v9.4) and means were separated using LSmeans at α = 0.05.

Results: Since each treatment was harvested at the same average target weight, there were no differences for live weight (P = 0.80). Similarly, there were no differences in USDA yield grade (P = 0.42), marbling score (P = 0.28), hot carcass weight (P = 0.89), dress percentage (P = 0.29), backfat thickness (P = 0.51), or kidney pelvic & heart fat (P = 0.86). However, OUT did have a larger ribeye area (P < 0.05) than SHD. No differences in objective fat color were observed between CWF and OUT (P = 0.87), while both were darker than CNF (P < 0.05); for subjective fat color SHD was darker than CWF and OUT (P < 0.01). Protein analysis showed CWF had more protein than CNF (P = 0.03) while no differences were observed for moisture content (P = 0.83), lipid content (P = 0.74), and ash content (P = 0.73). Differences were shown across treatment (P = 0.04) for thaw loss while no differences were detected for cook loss (P = 0.30). There were subjective color differences across treatment and day (P < 0.01) for overall color, worst point color, and percent discoloration, but discernable trends related to a specific treatment were not evident.

Conclusion: When taken to similar finishing weights, heat mitigation housing did not influence beef carcass characteristics but may impact retail color stability.

Funding Source: Georgia Agricultural Commodity Commission for Beef.

Keywords: beef, heat stress, meat quality

108 EFFECTS OF FEEDING OLIVE POMACE IN FINISHING BEEF RATIONS ON STRIP LOIN STEAK AND GROUND BEEF COLOR SHELF LIFE

M. Henson^1,*, E. Cumming¹, K. DeAtley², L. Smith², R. O. McKeith³, A. G. McKeith¹, ¹Animal Sciences & Agricultural Education, California State University, Fresno, Fresno, California, United States, ²Agriculture, California State University, Chico, Chico, California, United States, ³Agriculture, College of the Sequoias, Tulare, California, United States *amckeith@csufresno.edu

Objectives: As a result of California’s large olive oil industry, a problematic amount of olive pomace is created every year. Byproduct feeding to livestock is a common practice in California due to the vast range of produce grown in this state. The objective of this study is to determine the effects of supplementing olive pomace at differing percentages in a finishing beef cattle diet on whole muscle and ground beef color in a simulated retail display case setting.

Materials and Methods: Fifteen Angus cross heifers were fed a ration containing 0%, 10%, or 20% olive pomace (5 heifers per treatment) at CSU, Chico to a finished weight of approximately 590 kg. Cattle were slaughtered at the CSU, Chico Meat Lab and aged for 14 d. During fabrication, strip loins (with 0.6 cm of back fat) were pulled from each carcass, stored at ∼3°C, and transported to Fresno State to be wet aged under vacuum at ∼3°C for 14 additional days. Strips were then transported at ∼3°C to College of the Sequoias for color shelf-life study. Strip loins were then cut into 2.54 cm steaks, and 2 randomly selected steaks (one from each side of the carcass) were utilized for the color study. Approximately 906 g from each side was ground for ground beef color study. Both steaks and ground beef were placed in styrofoam trays, covered with overwrapped, and then placed in a retail display case with LED lighting. Daily samples were removed from the case and subjectively scored using the meat color guideline. Cuts were then instrumentally scored for L*,A*,B* values as well as having spectral color measurements taken utilizing a HunterLab MiniscanEZ. Samples were rotated daily to eliminate inconsistencies in lighting or temperature due to position in case. The study was concluded when more than 80% of the product was determined to be unpurchasable by consumer standards. Data was analyzed using the General Linear Model of SPSS as a 4 (day) × 3 (% olive pomace) factorial separating means by Tukey and LSD with alpha = 0.05.

Results: There were no day × treatment interaction effects; however, the research did reveal main effects of treatment and day. In the ground beef, meat from heifers fed 10% olive pomace showed slightly lower L* score (darker color) (P < 0.001), while the other two treatments did not differ. There was also a trend (P = 0.068) in the subjective color of ground beef showing cattle fed 20% to be more red than the other two. Subjective color in steaks, only main effects were shown where color changed over time, as would be expected with typical shelf life. The steaks from heifers fed 10% and 20% olive pomace had lower L* (P = 0.01) and A* (P < 0.001) values (darker and less red).

Conclusion: The results of this study showed that producers may incorporate up to 20% olive pomace into finishing beef rations without negatively impacting color.

Funding Source: Agriculture Research Institute Grant and California Olive Ranch.

Keywords: color, ground beef, olive pomace

109 DOUBLE FREEZING BEEF STRIP LOIN STEAKS AT BLAST OR CONSUMER FREEZING TEMPERATURES IN VACUUM AND OVERWRAPPED PACKAGING

M. Eckhardt^1,*, T. C. Tennant¹, T. E. Lawrence¹, L. W. Lucherk¹, ¹Agriculture, West Texas A&M University, Canyon, Texas, United States *meckhardt@wtamu.edu

Objectives: Seasonal changes in beef prices could be mitigated via rapid freezing cold storage technology until the market trends to a higher selling price. However, freezing can impact meat color and palatability if sold in an overwrapped package at retail. Our objective was to evaluate the combined effect of blast freezing vacuum packaged USDA Low Choice Longissimus lumborum beef steaks and consumer freezing of retail overwrapped steaks upon objective and subjective measures of beef palatability.

Materials and Methods: Data were analyzed via mixed models using a randomized complete block experimental design, with a 3 × 3 treatment structure of freezing treatments (unfrozen = NOT; blast frozen at −34.4°C = BF; consumer-frozen at −17.8°C = CF) to accomplish 9 treatment combinations; animal was the block, and individual steak (n = 288) was the experimental unit. Initial freeze occurred within 4 h from fabrication and packing, initially in the vacuum package, followed by the second freeze in the overwrap package. Objective color (L*, a*, b*) was collected throughout the duration of a 96-h overwrapped retail display after the initial freeze and thaw. Steaks were cooked to 71°C on a clam-shell grill. Descriptive sensory attributes (beef flavor identity, browned/roasted, bloody/serumy, fat-like, liver-like, fishy, oxidized, cardboard, rancid, refrigerator-stale, umami, bitter, sour, overall tenderness, and overall juiciness) were evaluated after both freezing treatments by trained panelists on a 100-point continuous line scale (0 = not; 50 = moderate; 100 = extremely). Slice shear force, expressible moisture, and total purge loss and cook loss percentages were evaluated.

Results: Steaks NOT sustained higher L* (P = 0.027) and a* (P < 0.001) values, whereas both freezing treatments (BF and CF) remained similar during the 96-h retail display. Total purge loss and cook loss percentages were affected by the initial and second freeze interaction (P ≤ 0.046); the least losses occurred in NOT steaks and greatest losses occurred in double-frozen steaks. Expressible moisture and SSF were minimally impacted by freezing; SSF of BF steaks in overwrap packages after retail display were lower (more tender; P = 0.039) than steaks NOT or CF. Though similar to steaks initially CF in the vacuum package and followed by a second freeze (CF/BF or CF/CF) in the overwrap package, steaks frozen once to simulate a consumer freeze (CF/NOT and NOT/CF) resulted in the overall driest (P = 0.006) ratings by panelists. Only bloody/serumy differed (P = 0.002) within the initial freeze, where steaks NOT in the vacuum package were rated higher than those BF or CF. During the second freeze in the overwrap package, BF steaks were rated higher for oxidized (P = 0.051) off-flavor than steaks CF and higher than both CF and NOT steaks for refrigerator-stale (P = 0.006) off-flavor; all other attributes did not differ (P ≥ 0.155). Double freezing steaks resulted in 2.8% to 3.1% additional average purge losses than NOT steaks. Although some freezing combinations that included a CF were generally lower for overall juiciness, BF vacuum packaged steaks had no effect on palatability when compared to NOT steaks.

Conclusion: The beef industry and consumers should feel confident using freezing as a means to extend shelf life of beef steaks.

Funding Source: Research coordinated by the National Cattlemen’s Beef Association, a contractor to the Beef Checkoff.

Keywords: blast, freezing, overwrap, packaging, sensory

110 EVALUATING DISCOLORATION PATTERNS IN WET-AGED BEEF: UTILIZING TIME-LAPSE VIDEO SURVEILLANCE

K. Elliott^1,*, D. G. LeDonne¹, G. G. Mafi¹, R. Ramanathan¹, M. M. Pfeiffer¹, ¹Department of Animal and Food Sciences, Oklahoma State University, Stillwater, Oklahoma, United States *madelyn.scott@okstate.edu

Objectives: Discoloration in fresh beef products poses a significant challenge for retailers, leading to discounts and economic losses. However, the precise patterns and mechanisms underlying discoloration remain inadequately understood. The objective of this study was to utilize time-lapse video technology to assess discoloration patterns in the longissimus lumborum (LL) muscle.

Materials and Methods: USDA Low Choice strip loins (n = 8/aging time) were wet-aged for 14 d and 28 d postmortem. The loins were cut into 2.54 cm steaks and placed in retail display under time-lapse video surveillance for 147 h. The steaks assigned to video surveillance were individually placed under an Apple iPad mini to take clear and consistent recordings. The iPad was set on a Tablet Mount to position the iPad over the retail case and each individual steak. Time-lapse video surveillance was taken using the Lapse It© app from the Apple App Store. The app was set to record every hour and was monitored periodically until steaks reached 100% discoloration. Each steak was assigned quadrants to track discoloration patterns. Quadrant 1 borders the subcutaneous fat and the ventral side. Quadrant 2 borders the subcutaneous fat and the dorsal side. Quadrant 3 borders quadrant 2 and the dorsal side. Quadrant 4 borders quadrant 1 and the ventral side. The time lapse videos of each steak were reviewed hourly, and discoloration by quadrant was identified over time. Data was analyzed using the GLIMMIX Procedure of SAS to determine the least-squares means in which P < 0.05 was considered significant.

Results: There were significant evidence (P < 0.05) quadrants 1 and 2 began discoloration at nearly the same rate around hour 112. Discoloration (P < 0.05) occurred in quadrant 3 third at hour 121, while quadrant 4 was the last (P < 0.05) to begin discoloration at hour 127 in both 14 d and 28 d sample groups. Complete (100%) discoloration was achieved following the same pattern.

Conclusion: Therefore, this study suggests discoloration patterns in the LL muscle can be predicted. Beef strip steaks from the LL begin discoloration along the subcutaneous fat on the dorsal side and ventral side, followed by the most interior quadrant of the steak on the dorsal side and ending at the most interior quadrant on the ventral side. Further research should be done to evaluate other muscles and species for patterns.

Keywords: beef, discoloration, time-lapse, video surveillance

111 EARLY WEANING STRATEGY ON THE CARCASS TRAITS AND MEAT QUALITY OF NELLORE CATTLE FINISHED IN THE PASTURE WITH SUPPLEMENTATION

J. A. Torrecilhas^1,*, I. A. Reis², R. C. Rodrigues¹, P. L. G. Melo¹, P. I. Lima¹, L. M. L. Vitoretti¹, R. S. Nogueira¹, L. A. L. Chardulo¹, R. A. Curi¹, M. R. Vicari³, G. L. Pereira¹, ¹Department of Breeding and Animal Nutrition, ²Department of Animal Science, Sao Paulo State University, Botucatu, ³Department of Molecular Structural Biology and Genetics, Ponta Grossa State University, Ponta Grossa, Brazil *cferrei@purdue.edu

Objectives: Early weaning and postnatal nutritional management are a crucial strategy in livestock production systems and can affect long-term beef cattle growth. This study aimed to evaluate the effect of early weaning associated with a post-weaning supplementation and compare it with traditional weaning on the meat quality of Nellore cattle.

Materials and Methods: Forty male Nellore calves raised in the pasture were submitted into one of 2 treatments: early weaning (EW) 120 d; and conventional weaning (CW) 205 d. The EW group was supplemented with 1% of BW of protein + energy until 205 d. On 205 d, both groups were combined in a single group and fed with pasture and 0.3% protein + energy supplementation for 488 d. During the finishing phase (222 d) all the animals were raised in the pasture and supplemented (0.5% BW). After 222 d, all cattle were slaughtered in a commercial slaughterhouse. All carcasses were weighed to determine the hot carcass. After 48 h, the Longissimus thoracis between 12^th and 13^th ribs from the left side of each carcass were collected, vacuum packaged, and aged for 5 and 15 d. The samples were used to determine pH, color (L*, a*, b*, Chroma, and hue), purge loss, cooking loss, water-holding capacity, Warner Bratzler-shear force (WBSF), and lipid content. The meat quality traits data were analyzed by mixed model adapted to repeated measures, where treatment (early and conventional) and ageing time (5 and 15 d) were considered as fixed factors, and samples (ageing) were considered as random effects. The estimated marginal means were tested to significative differences among treatments, time, and interactions, and the hot carcass weight and lipid content were analyzed by non-paired Student t-test. For all tests, significance was declared as P < 0.05 was used to analyze the data.

Results: The cattle from EW presented hot carcass weight similar (P = 0.117) to CW (337.94 vs. 324.23 kg, respectively). The pH, L*, a*, b*, chroma, and hue were similar (P ≥ 0.05) between treatments. The weaning strategy did not affect (P ≥ 0.05) purge losses, cooking losses, and WHC. The shear force and lipid content were similar (P ≥ 0.05) in the cattle meat from both groups, with means of 65.04N and 1.81%, respectively. On the other hand, the increase (P < 0.05) of ageing time reduced the a* and chroma parameters while the hue increased.

Conclusion: Our data suggested that the early weaning strategy did not impact the meat quality of Nellore cattle supplemented during the growing phase and finished in the pasture with supplement.

Funding Source: Sao Paulo Research Foundation–FAPESP (grant 2019/12851-1) and fapesp process number 2023/16127-1 and 2022/10240-8.

Keywords: cattle, early weaning, meat quality

112 COMPARING COLOR STABILITY AND SHEAR FORCE OF PORK CHOPS AGED AS CHOPS AND ROASTS

K. A. Jallaq^1,*, S. J. Drayer¹, A. C. Dilger¹, B. N. Harsh¹, ¹Animal Sciences, University of Illinois Urbana-Champaign, Urbana, Illinois, United States *kjallaq2@illinois.edu

Objectives: The study objective was to determine whether aging pork loins as chops or roasts impacts color stability or instrumental tenderness of pork loin chops.

Materials and Methods: Loins were sourced from pigs raised at the University of Illinois Swine Research Center (Champaign, IL). Chops (2.54 cm) and roasts (5.08 cm) were cut sequentially from 48 boneless Canadian back pork loins at 1 d postmortem, vacuum packaged, and aged at 4°C until 14 d postmortem. After aging, loin roasts were cut into 2.54 cm chops for display. Chops from each aging type were designated for either simulated retail display or Warner-Bratzler shear force (WBSF) analysis. Shear force chops were vacuum-sealed and frozen at −20°C until analysis. Chops for simulated retail display were individually packaged on Styrofoam trays and overwrapped with polyvinylchloride film. Packages were allocated to shelves randomly, and rotated between shelves each day of the trial, to contain both treatments. Seven to nine panelists observed chops on d 1, 3, 5 and 7 of display and scored chop discoloration on a 10-cm line scale corresponding to perceived percent discoloration. Objective color was evaluated through film with a HunterLab MiniScan EZ spectrophotometer on d 1, 3, 5, and 7 of retail display. Chops were thawed at 4°C for 24 h and cooked on Farberware open-hearth grills to an internal temp of 63°C. Chops were flipped at the half way point (31°C). Temperature of individual chops was monitored using copper-constantan thermocouplesplaced in the geometric center of the chops. Thermocouples were attached to an Omega HH378 Data Logger Thermometer. Chops were allowed to cool to approximately 25°C and were individually weighed before and after cooking to measure cook loss percentage. Chops were cored parallel to muscle fiber direction. Four 1.25 cm cores were sheared perpendicular to muscle fiber direction using a Texture Analyzer TA.HD Plus with a load cell capacity of 100 kg and a blade speed of 3.33 mm/s. The average of the 4 cores was recorded as the sample’s WBSF. Retail display data were analyzed as a repeated measure in time using the MIXED procedure of SAS. Instrumental tenderness data were analyzed as a t-test using the TTEST procedure of SAS.

Results: There were no differences between shear force (P = 0.68) or cook loss (P = 0.80) between treatments. While all chops became darker (L*) over time, loin chops aged as roasts were paler than loin chops aged as chops across all days of display (P ≤ 0.01). For instrumental lightness, there was no interaction between aging type and day of display (P = 0.91). While all chops became less red (a*) over time, no differences between treatments were observed until d 7 of display where loin chops aged as chops were slightly redder (P = 0.03). Loin chops aged as roasts were yellower (P ≤ 0.01) (b*) than those aged as chops at d 1 of display, but no differences in yellowness (P ≥ 0.09) were observed by d 3 and on. No differences in visual discoloration (P = 0.86) were observed between loin chops aged as chops or roasts until d 7 of display when loin chops aged as roasts were more discolored than those aged as chops (P ≤ 0.01).

Conclusion: How pork chops are aged prior to retail case shelving or for research shelf life evaluation may influence color stability. Further research is needed to explore the potential driving factor between color change differences between aging types.

Keywords: aging, color stability, pork, quality

113 IMPROVING THE OXIDATIVE STABILITY OF MODIFIED ATMOSPHERE PACKAGED FRESH GROUND TURKEY USING CORBION ANTIOXIDANTS

P. Farshi^1,*, G. Mccoy¹, L. English¹, J. Leader¹, B. Howard¹, R. Garza², R. Ames², ¹Research and Development, ²Business Development, Corbion, Lenexa, Kansas, United States *garrett.mccoy@corbion.com

Objectives: Antioxidants play a crucial role in slowing the natural process of oxidation, delaying rancidity, and reducing color loss in fresh meat products. Corbion offers preservation solutions through its Origin^™ portfolio of natural antioxidants. The aim of this study was to evaluate the natural antioxidants in fresh turkey ground meat with Modified Atmosphere Packaging (MAP) (30% CO2 and 70% N2) during the storage simulated retail display of 2 ± 1°C for 13 d.

Materials and Methods: Fresh turkey (boneless skin-on thigh meat) was sourced from a commercial meat processor and processed at Corbion Innovation Center in a controlled environment at 2 ± 1°C. The turkey was course ground (10 mm plate) and mixed in 18.14 kg batches for 3 min in 30 s intervals of forward reverse cycles, followed by adding 0.20% Origin^™ Powder RO2 (Natural Flavor) or 0.20% Origin^™ RO50 (Natural Flavor), while mixing continued for 5 min. Mixed turkey was ground again through a 6.35 mm plate, and portioned into a 250 g samples on 1S Styrofoam trays with an absorbent pad. The trays with sample were overwrapped with low-barrier oxygen permeable PVC film and packaged in a 3 mil (oxygen transmission rate <63 cm³/m²) polypropylene bags flushed with gas mixture consisting of 30% CO₂ and 70% N₂. The trays were stored in a display case with LED light (4000 Kelvin) at 2 ± 1°C for 13 d. Throughout the study, Thiobarbituric Acid Reactive Substances (TBARS) assay was conducted along with measuring the instrumental L*, a*, and b* values using a Hunterlab colorimeter. TBA reactive MDA (malondialdehyde) values were reported as mg MDA/kg sample. SAS 9.4 software was used to test the significant difference at α = 0.05. Experiments were done in triplicates. One way analysis of variance (ANOVA) was conducted followed by Tukey’s test.

Results: The inclusion of 0.20% Origin^™ Powder RO2 or 0.20% Origin^™ RO50 in MAP fresh ground turkey resulted in significantly (P < 0.05) lower TBARS value compared to the negative control sample prepared without any antioxidants. There was no significant difference (P > 0.05) in the color values (L*, a*, and b*) for all the tested treatments (data not shown).

Conclusion: Fresh ground turkey samples containing Origin^™ Powder RO2 or Origin^™ RO50 demonstrated more oxidative stability than the negative control sample. Antioxidant ingredients are necessary along with MAP packaging to protect the ground turkey against the formation of oxidative components that may be responsible for off-flavors in fresh ground turkey.

Keywords: antoixidant, turkey

114 DOES SIZE MATTER? COMPARING SHEAR FORCE OF PORK CHOPS OF DIFFERENT THICKNESSES

N. L. Adolph^1,*, S. K. Guthrie¹, B. N. Harsh¹, A. C. Dilger¹, ¹Animal Sciences, University of Illinois, Urbana-Champaign, Urbana, Illinois, United States *sarahkr2@illinois.edu

Objectives: The objective of this study was to determine how pork chop thickness affects tenderness when chops are cooked similarly using constant temperature monitoring. Chop thickness is typically controlled within an experiment to minimize variation; this study aims to determine if that degree of control is needed.

Materials and Methods: Pairs of chops were cut from 48 boneless pork loins aged for 14 d postmortem. In each pair, one chop was 2.54 cm (thin) and the other was 5.08 cm (thick). Thickness was controlled by using a ruler to precisely measure chop thickness while hand-cutting with a knife. Chops were then vacuum-packaged and stored frozen for Warner-Bratzler shear force (WBSF) analysis. Chops were thawed for 24 h at 4°C prior to cooking on open hearth grills with constant internal temperature monitoring with thermocouples placed at the approximate geometric center of chops and attached to a data logger thermometer. Chops were cooked to an internal temperature of 31°C, flipped, and cooked to 63°C. Initial, off-grill, and final resting temperature were recorded for each chop. Chops were cooled to approximately 25°C, and four 1.25 cm cores were removed parallel to the muscle fiber direction. Cores were sheared perpendicular to muscle fiber orientation using a TA.HD plus Texture Analyzer. Chop weights before and after cooking were used determine cook loss. Data were analyzed as a paired t-test using SAS to determine differences in WBSF and cook loss between “thin” and “thick” chops. Loins were classified as tender (WBSF < 2.9) and tough (WBSF > 3.5), and then evaluated as a one-way ANOVA using the MIXED procedure of SAS. Pearson correlation coefficients between thick and thin WBSF were determined using the CORR procedure of SAS. Differences were considered significant at P ≤ 0.05 and trends were considered at P ≤ 0.10.

Results: Final (63.3 ± 0.6) and resting (65.7 ± 1.6) temperatures were not different (P ≥ 0.67) between thick and thin chops. Cook loss was approximately 2 units greater (P < 0.01) in thick chops compared with thin chops. Cook loss percentages between thick and thin chops were not correlated (r = −0.207, P = 0.16). Warner-Bratzler shear force tended (P = 0.10) to be reduced in thick (3.12 kg) compared with thin (3.26 kg) chops. Warner-Bratzler shear force values between thick and thin chops were moderately correlated (r = 0.48, P < 0.001). When comparing tender and tough chops, groups were different regardless of the thickness of chops. For thin chops, WBSF was increased (P < 0.001) 1.16 kg in tough chops compared with tender chops. In thick chops, WBSF was increased (P < 0.001) 1.49 kg in tough compared with tender chops. When groups were mixed to contain both thick and thin chops, WBSF was increased (P < 0.001) 1.32 kg in tough compared with tender chops.

Conclusion: Cook loss percentage did differ with chop thickness even with precise temperature monitoring. Thus, when conducting research focused on cook loss precise control of chop thickness is important. Overall, there were no differences in WBSF for chops at different thicknesses suggesting that controlling for chop thickness is less important when tenderness is of primary interest.

Keywords: meat quality, pork, Warner-Bratzler shear force

115 FREQUENCY OF LACTATION AND INTACT MALES AND THEIR ASSOCIATION WITH CARCASS OUTCOMES IN FINISHED CATTLE

T. C. Petit^1,*, M. E. Eckhardt¹, L. W. Lucherk¹, T. E. Schwartz¹, T. R. Brown², T. E. Lawrence¹, ¹Agriculture, West Texas A&M University, Canyon, Texas, United States, ²Cargill Meat Solutions, Cargill Inc., Minneapolis, Minnesota, United States *tcpetit1@buffs.wtamu.edu

Objectives: Accumulation of excess fat may cause fat cells to produce estrone, potentially initiating lactation without pregnancy. Intact males divert more energy to muscle production and finish slower, due to endogenous testosterone. Our objectives were to 1) audit cattle to determine the frequency of intact males and lactating steers or heifers, and 2) to determine carcass performance and value of intact males vs steers and of the lactating animals compared to their pen mates.

Materials and Methods: Cattle (n = 17,507) were audited during harvest, originated from 32 feedlots, and consisted of native steers (n = 5,387) and heifers (n = 5,019), as well as dairy-cross steers (n = 3,306) and heifers (n = 3,795). All cattle were assessed for lactation, and steers were manually palpated to detect testicles. Carcass outcomes for audited lots were obtained to compare cattle identified as lactating or intact males to the remaining balance of their lots. Frequency data were analyzed via chi-square methods, whereas mixed models were used to determine the effect of lactation or intact testicles among cattle-type populations regarding carcass performance.

Results: Of the sampled population, 26.87% of cattle (n = 4,704) were identified as lactating. Dairy-cross heifers were lactating at the greatest (P < 0.01) frequency (49.51%), followed by native heifers (29.51%), dairy-cross-steers (16.85%), and native steers (14.61%). Of male cattle (n = 8,693) evaluated for testicles, 1.04% (n = 90) were intact males. Intact dairy-cross animals marketed as steers tended to occur at a greater rate (1.30%; P = 0.06) than animals marketed as native steers (0.87%). In the male population, 4 cattle (3 dairy-cross; 1 native) were lactating intact males. Comparisons between lactating (LH) and non-lactating heifers (NLH) indicated LH were leaner as evidenced by less 12^th rib AUTHOR: Please define if possible.s.c. fat (FAT), lower marbling score (MS), lower calculated yield grade (YG), less calculated empty body fat (EBF), and less kidney-pelvic-heart fat (KPH) simultaneous with darker muscle color, and larger longissimus muscle area (LMA) than NLH (P < 0.01). Furthermore, LH had lighter hot carcass weights (HCW) but returned a greater (P < 0.01) price per weight unit. No difference (P = 0.10) in total value was detected between LH and NLH. In contrast to heifers, lactating steers (LS) had heavier HCW, more FAT, more KPH, higher YG, and more EBF, along with brighter lean color, and greater MS, than non-lactating steers (NLS) (P ≤ 0.04). No difference between LS and NLS was detected for LMA (P = 0.15); LS were priced less (P < 0.01) per unit of weight but returned more (P < 0.01) total value. Intact males had less FAT, larger LMA, less KPH, lower YG, and lower EBF, concomitant with darker lean color and lower MS compared to steers (P < 0.01). No differences occurred in HCW (P = 0.20) or total value (P = 0.94) between intact males and steers; however, steers were valued at a greater price per unit weight (P = 0.02).

Conclusion: The results demonstrate intact males occur at a low frequency in the fed beef population, whereas lactating heifers and steers occur at notable rates. Lactation unequally influences carcass quality, yield, and value outcomes of steers and heifers. These data suggest that lactating males and females impact carcass outcomes and total value, and suggest the need for further research to manage this unwanted outcome.

Funding Source: Funded by the West Texas A&M University Beef Carcass Research Center.

Keywords: fed cattle, lactation, milk, testicles

116 INFLUENCE OF RETAIL CASE CONDITIONS ON INSTRUMENTAL COLOR MEASUREMENTS OF BEEF STEAKS

S. E. Shimer^1,*, S. L. Shoup¹, E. S. Neal², J. W. S. Yancey¹, D. Setyabrata³, J. F. Legako², K. R. Vierck¹, ¹Department of Animal Science, Division of Agriculture, University of Arkansas System, Fayetteville, Arkansas, United States, ²Department of Animal and Food Science, Texas Tech University, Lubbock, Texas, United States, ³Department of Animal Science, University of Arkansas, Fayetteville, Arkansas, United States *vierck@uark.edu

Objectives: The objective of this study was to determine the influence of retail case type, package, and muscle on instrumental meat color traits of beef steaks.

Materials and Methods: Paired beef strip loins (n = 20/subprimal), eye of rounds, and top sirloin butts were selected from USDA Choice carcasses. Subprimals were wet aged for 14 d in the absence of light. Following aging, subprimals were fabricated into 2.54 cm thick steaks representative of the Longissimus lumborum (LL), Semitendinosus (ST), and Gluteus medius (GM). Steaks were then randomly assigned into one of 3 packaging schemes: overwrap (OW), carbon monoxide modified atmosphere packaging (MAP), or vacuum (VAC). Following packaging, steaks were transported under refrigeration to simulate a case-ready retail scenario. Samples were aged an additional 7 d in the dark, then randomly allotted to a 7-d retail display under continuous lighting in one of 2 retail cases: a traditional multideck case (MD) and a closed door refrigerated case (CD). Steaks designated for color analysis were analyzed for instrumental color every 12 h using a spectrophotometer. Data were analyzed as a 2 × 3 × 3 factorial arrangement, where muscle, packaging type, and case type served as fixed effects. Collection round and time were incorporated into the model as random effects. Least-squares means were separated using α ≤ 0.05.

Results: No significant case × package × muscle × day interactions were observed for any traits analyzed (P ≥ 0.983). L* was influenced by the muscle × packaging interaction (P < 0.001) and case type (P = 0.020). Semitendinosus steaks packaged in all packaging schemes were lighter than all other treatments (P < 0.05). Steaks stored in CD cases were lighter (P < 0.05) compared to steaks stored in MD cases. Redness, or a*, was impacted by both a case × packaging (P = 0.008), where OW and MAP steaks displayed in a CD were redder than MD MAP and OW steaks (P < 0.05). All treatments were redder than any VAC treatments, regardless of case type (P < 0.05). a* was also impacted by case × muscle interaction (P = 0.038). ST and LL steaks, regardless of case type, were more red than GM steaks (P < 0.05). Chroma was impacted by the case × muscle × package interaction (P = 0.028). Within each muscle, CD MAP and OW steaks had a greater saturation index compared to their MD counterparts (P < 0.05). However, VAC steaks, regardless of case type, were the lowest in chroma (P < 0.05). Hue angle and b* were both influenced by a case × muscle interaction (P < 0.001) and case × package interaction (P = 0.005). Semitendinosus steaks displayed in both cases were more yellow compared to LL and GM steaks of both case treatments (P < 0.05). For the case ×packaging interaction, steaks packaged in MAP and OW in both CD and MD cases had an increased discoloration rate than all VAC treatments (P < 0.05).

Conclusion: These data indicate that retail case type does play a role in meat color stability, especially redness and saturation index. However, color stability is also driven by muscle and packaging type as factors that can extend color and therefore shelf life of beef products. This knowledge may be used not only to improve shelf life but also to reduce energy use of cases at retail.

Funding Source: Research coordinated by the National Cattlemen’s Beef Association, a contractor to the Beef Checkoff.

Keywords: beef color, muscle, packaging, retail case, retail display

117 DETERMINING THE EFFECT OF ELECTROSTATIC ASSISTED FREEZING ON SHELF STABILITY OF LONGISSIMUS LUMBORUM

J. T. Looper^1,*, S. R. Hene¹, S. D. Lee¹, T. G. O’Quinn¹, M. D. Zumbaugh¹, M. D. Chao¹, ¹Animal Sciences and Industry, Kansas State University, Manhattan, Kansas, United States *jtlooper@ksu.edu

Objectives: Due to the damage caused by ice crystal formation, previously frozen beef products tend to discolor quicker than their fresh-never frozen counterpart. A novel approach to this issue is the incorporation of an electrostatic field (EF) during the freezing process. Previous studies have shown that EF may improve yield of previously frozen beef by reducing cellular damage. However, many of these studies overlook the potential of this technology to extend the shelf-life of beef. Thus, the objective of this study was to determine the effect of EF assisted freezing on the instrumental and descriptive color during the retail display of previously frozen beef striploins.

Materials and Methods: Longissimus lumborum (LL) were collected from both sides of 12 USDA Choice carcasses, and each LL was halved into 2 equal parts (n = 48). Halves were randomly assigned to one of 4 freezing treatments: 0, 2, 4, or 8 kV. Halves were frozen for 24 h in a walk-in freezer (−20°C) under the designated EF treatment. Following treatment, frozen LL were vacuum packaged and stored in the same freezer for 8 d before thawing in a walk-in cooler set at 2°C for 72 h. All samples were thawed to at least 0°C in the geometric center, and swabs and purge were collected from each portion for aerobic plate count (APC). LL halves were immediately fabricated into steaks, and one 2.54-cm steak from each portion was overwrapped and subjected to 10 d of simulated retail display. Instrumental (L*, a* and b*) and descriptive (trained panel (n = 8) consisting of faculty and graduate students) color measurements were conducted each day.

Results: During the display period, an interaction between display day and EF treatment was observed for discoloration (P < 0.05). All treatments remained statistically the same until days 9 and 10 in which 4kV samples reported less discoloration than the other treatments, while the others were not found to be different from each other. Main effects for treatment and display were also found for L*, a*, and b* (P < 0.01). For the display effect, a* and b* values decreased throughout the 10-d display while L* increased until day 4 then remained constant through the remainder of display (P < 0.01). For the treatment effect, a* and b* values were the highest in the 4kV group, followed by 0 and 2 kV, while the 8kV group had the lowest values (P < 0.01). L* values for 0 and 2 kV groups were higher than those from 4 and 8 kV treatments (P < 0.01). Finally, no difference in APC for both swabs and purge were observed among the EF treatments (P > 0.05).

Conclusion: The 4kV group showed better color stability both instrumentally and descriptively throughout the display period, and such difference in shelf-life was not due to microbial load differences. The improvement in post-thaw color stability from the 4kV treatment could be due to a treatment that resulted in the least amount of cellular damage during freezing. However, the exact mechanism of such an effect requires further investigation. This retention in color stability could provide economic incentives beef processors, so further research is needed to investigate the mechanisms that could affect color retention of EF assisted frozen beef.

Funding Source: Research coordinated by the National Cattlemen’s Beef Association, a contractor to the Beef Checkoff.

Keywords: aerobic plate count, color, display day, electrostatic freezing, striploin

118 NATIONAL BEEF QUALITY AUDIT 2022: THE RELATIONSHIP BETWEEN ADJUSTED FAT THICKNESS, MARBLING SCORES, AND USDA QUALITY GRADE OF FED STEERS AND HEIFERS

A. De La Zerda^1,*, T. R. Mayer¹, T. E. Schwartz¹, S. E. Borders¹, K. B. Gehring¹, D. B. Griffin¹, C. R. Kerth¹, K. E. Belk², J. A. Scanga², M. N. Nair², M. M. Pfeiffer³, G. G. Mafi³, T. E. Lawrence⁴, T. C. Tennant⁴, L. W. Lucherk⁴, T. G. O’Quinn⁵, E. S. Beyer⁵, P. D. Bass⁶, L. G. Garcia⁷, B. M. Bohrer⁷, J. A. Pampek⁷, A. J. Garmyn⁸, R. J. Maddock⁹, C. C. Carr¹⁰, T. D. Pringle¹⁰, T. L. Scheffler¹⁰, J. M. Sheffler¹⁰, A. M. Stelzleni¹¹, J. M. Gonzalez¹¹, K. R. Underwood¹², B. N. Harsh¹³, C. M. Waters¹⁴, J. W. Savell¹, J. B. Douglas¹⁵, K. M. Harr³, ¹Animal Science, Texas A&M University, College Station, Texas, United States, ²Animal Science, Colorado State University, Fort Collins, Colorado, United States, ³Animal Science, Oklahoma State University, Stillwater, Oklahoma, United States, ⁴Agricultural Sciences, West Texas A&M University, Canyon, Texas, United States, ⁵Animal Sciences and Industry, Kansas State University, Manhattan, Kansas, United States, ⁶Animal, Veterinary and Food Sciences, University of Idaho, Moscow, Idaho, United States, ⁷Animal Science, The Ohio State University, Columbus, Ohio, United States, ⁸Animal Science, Michigan State University, East Lansing, Michigan, United States, ⁹Animal Sciences, North Dakota State University, Fargo, North Dakota, United States, ¹⁰Animal Sciences, University of Florida, Gainesville, Florida, United States, ¹¹Animal & Dairy Science, University of Georgia, Athens, Georgia, United States, ¹²Animal Science, South Dakota State University, Brookings, South Dakota, United States, ¹³Animal Sciences, University of Illinois, Champaign, Illinois, United States, ¹⁴Agriculture, California State University, Chico, California, United States, ¹⁵Animal Sciences, Colorado State University, Fort Collins, Colorado, United States *aggie_0198@tamu.edu

Objectives: The objective of this portion of the National Beef Quality Audit (NBQA) 2022 was to assess the relationship between adjusted fat thickness at the 12^th-13^th rib interface, marbling scores, and USDA quality grades.

Materials and Methods: Approximately one week’s worth of instrument grading data were collected per month from July of 2021 to June of 2022 from 6 major beef packing companies for a total of 4,418,666 carcasses. The instrument grading data collected included many factors, but this presentation focuses only on adjusted fat thickness, marbling scores (Abundant, Moderately Abundant, Slightly Abundant, Moderate, Modest, Small, Slight, Traces, and Practically Devoid) and USDA quality grades (Prime, Top Choice, Low Choice, and Select). Additionally, carcasses with defects observed by the USDA Grader were classified as “Other”, which included Standard, Commercial, Utility, Dark Cutter, Blood splash, Hard Bone, and Calloused Ribeye. Data were analyzed using Microsoft Excel for Mac 2024 (Microsoft Corporation) and JMP Software (JMP Pro, Version 16. SAS Institute, Cary, NC, 1989-2021). Least-squares means of fat thickness by marbling scores were determined using the Fit Model Standard Least Squares function, one-way analysis of variance, and mean comparisons were conducted using Student’s t test and an alpha of P < 0.05. The Fit Y by X function was used for summary statistics and one-way analysis of variance to observe the correlation between fat thickness and marbling scores.

Results: As shown in Figure 1, as the adjusted fat thickness increased, the percentage of carcasses grading Prime and Top Choice increased, whereas the percentage of carcasses grading Select decreased. Low Choice trended upwards in frequency until fat thickness reached 1.01 cm, and then the percentage of carcasses grading Low Choice started to decline. Finally, the percentage of carcasses for both Select and Other saw a downward trend once the fat thickness increased above 0.63 cm. Increasing fat thickness is positively related (r = 0.36; P < 0.0001) to increasing marbling scores, which is like the relationship found in NBQA-2016 (r = 0.36). Except for Practically Devoid and Traces, as marbling scores increased from Slight to Abundant, fat thickness increased (P < 0.001).

Conclusion: This portion of the NBQA-2022 documented the relationship between an increase in fat thickness and how the frequencies of grades were influenced. Use of this large-scale data set to evaluate these relationships shows how this information may be useful for evaluating the interrelationships among factors involved in USDA quality grades and USDA yield grades.

Funding Source: Research coordinated by the National Cattlemen’s Beef Association, a contractor to the Beef Checkoff.

Keywords: fat thickness, National Beef Quality Audit, quality grades

119 THE INFLUENCE OF CARCASS WEIGHT AND EXTERNAL FAT THICKNESS ON CHILLING RATE OF COMMERCIAL BEEF CARCASSES

K. M. Gundersen^1,*, M. A. Fevold², R. J. Maddock¹, E. S. Beyer¹, K. R. Maddock-Carlin¹, ¹Animal Sciences, North Dakota State University, Fargo, North Dakota, United States, ²Animal Sciences, University of Nebraska-Lincoln, Lincoln, Nebraska, United States *kiersten.gundersen@ndsu.edu

Objectives: Temperature decline of beef carcasses impacts palatability, yield, food safety, and shelf life. With the continual development of heavier carcasses, it is unknown whether current industry chilling standards are still chilling beef carcasses fully before fabrication. Therefore, the objectives of this study were to evaluate the impact of carcass weight and external fat thickness on the chilling rate and shelf life of commercial beef carcasses.

Materials and Methods: Commercial beef carcasses (N = 60) were collected from a Midwest beef processing plant. Carcasses were initially selected based on a visual assessment of fat cover to ensure equal numbers of “thin”, “medium”, and “fat” carcasses were selected. The external fat thickness was divided into 3 groups based on the measurement taken at the 12^th rib: thin (TH) [≤ 1.02 cm], medium (MED) [1.27 cm to 1.75 cm], and fat (FT) [≥ 1.78 cm]. Based on the carcasses selected for fat cover, the carcasses were segregated into body weight groups including light (LIT) [≤ 362.9 kg], intermediate (INT) [363.3 kg to 408.2 kg], and heavy (HVY) [≥ 408.7 kg]. Upon selection, temperature decline was measured at the Semimembranosus (SEM) using a temperature data log with a 20 cm probe every hour for 24 h. After chilling, top beef rounds (IMPS 169) and top sirloin butts (IMPS 184) were collected from the fabrication floor and brought back to North Dakota State University for processing. Cuts were fabricated into 2.5 cm steaks and assigned a random identification number. One steak from SEM and Gluteus medius (GM) were placed in a foam tray and covered with polyvinyl film and placed under constant direct light for 7 d. Objective L*, a*, and b* measurements were collected every 24 h using a Minolta colorimeter. The 2 × 3 factorial model was evaluated for significance (P ≤ 0.05) with carcass weight and fat depth as fixed effects per hour of temperature decline. The factorial model also evaluated for color stability in a 7 d shelf life study.

Results: There were no interactions (P > 0.05) between carcass weight, fat depth, and temperature decline. LIT and INT carcasses chilled at a faster rate (P < 0.05) than HVY carcasses for hour 1 and 2. Similarly, INT carcasses chilled at a faster rate (P < 0.05) than HVY carcasses up to hour 9. TH and MED fat covered carcass groups chilled faster (P < 0.05) than FT covered carcasses between hours 2 and 7. However, internal temperature never recorded below 11.8°C in any SEM within the 24 h duration. In GM samples, LIT carcasses demonstrated greater color stability (P < 0.05) with higher a* values in comparison to INT and HVY carcasses from 4 to 6 d.

Conclusion: These results determined fat depth and carcass size impacts temperature decline. Fat measurements could be evaluated to identify a potential correlation of 12^th rib fat depth and temperature decline. Also, carcass size impacted shelf life of only the GM indicating individual muscles are impacted differently. Further investigation is needed to understand the impact of carcass weight and fat depth on the shelf life of other muscles in the round.

Funding Source: Research coordinated by the National Cattlemen’s Beef Association, a contractor to the Beef Checkoff.

Keywords: beef, carcass weight, chilling rate, fat thickness, temperature

120 EFFECTS OF PACKAGING TYPES ON THE COLOR AND LIPID OXIDATION OF GROUND BEEF, PORK, AND CHICKEN

N. Jewell^1,*, K. Harr¹, A. Scott¹, A. Sharma¹, G. Mafi¹, M. Pfeiffer¹, R. Ramanathan¹, ¹Animal and Food Sciences, Oklahoma State University, Stillwater, Oklahoma, United States *noah.jewell@okstate.edu

Objectives: The adoption of case-ready meat allows meat processors to use various packaging systems to extend shelf life. In general, the gas compositions within modified atmospheric packaging are similar between species. The composition of glycolytic vs. oxidative fiber type and lipid types varies between species. However, limited studies have compared the impact of packaging across species such as beef, chicken, and pork. The objective of this study was to evaluate the effects of various packaging methods on the color and lipid oxidative characteristics of ground beef, pork, and chicken patties.

Materials and Methods: Beef chuck rolls, pork Boston butts, and skin-on, bone-in chicken thighs were procured from two commercial meat processing facilities. All species were first coarse ground, with chicken removed of skin and bone, and then finely ground to make 100 g patties using a handheld patty former. The patties from each species were randomly assigned to 4 packaging conditions [polyvinyl chloride overwrap (PVC), vacuum, high-oxygen modified atmospheric packaging (HiOx-MAP), and carbon monoxide-MAP (CO-MAP)]. The CO-MAP gas flush consisted of 0.4% oxygen, 30% carbon monoxide, and 69.6% nitrogen, while the HiOx-MAP gas flush consisted of 80% oxygen and 20% carbon dioxide. The patties were stored in the dark at 2°C for 5 d. L*, a*, and b* values of all patties were recorded during storage using a HunterLab MiniScan spectrophotometer. Lipid oxidation was determined as thiobarbituric acid reactive substances (TBARS) values. The experiment was replicated 5 times (n = 5). The data were analyzed using the Proc GLM Procedure of SAS.

Results: As expected, there was a significant species × packaging effect (P < 0.05) on lightness. Ground chicken in vacuum and CO-MAP was lighter in color, while pork and ground beef patties in HiOx-MAP were lighter (P < 0.05) than other beef and pork treatments. There was a significant species × packaging × day effect (P < 0.05) for redness. Ground pork and chicken patties packaged in HiOx-MAP showed minimal changes in redness, while ground beef patties in HiOx-MAP demonstrated several units of decrease in redness with increased storage time. The numerical increase in redness with storage time (day 0 vs. day 5) in CO-MAP was greater for ground beef than pork and chicken. There was a significant species × packaging interaction that occurred for lipid oxidation. Pork patties in HiOx-MAP had lower lipid oxidation than chicken and beef in HiOx-MAP (beef > chicken > pork; P < 0.05). Beef contains more hemeproteins compared to pork and chicken, which act as a prooxidant. Additionally, pork contains more catalase, which can remove lipid oxidation products from the muscle. Hence, lower heme content and increased catalase activity resulted in lower pork oxidation values compared to beef products. However, pork and chicken have similar lipid oxidation in CO-MAP (beef > chicken = pork; P < 0.05).

Conclusion: The results suggest species-specific differences in the effect of packaging on color and lipid oxidation. Both ground pork and chicken showed color and lipid stability in a high-oxygen environment, while ground beef was prone to oxidative changes. Both ground pork and chicken had similar color and lipid oxidation profiles in CO-MAP and HiOx-MAP.

Keywords: ground beef, lipid oxidation, meat color, packaging

121 EFFECTS OF BUFFERED VINEGAR ON THE REFRIGERATED SHELF LIFE OF CATFISH FILLETS

G. Tang^1,*, X. Zhang¹, L. Zaldivar¹, E. Little¹, S. W. Smith¹, M. Bishop¹, Z. Molloy¹, B. Ott², P. Allen³, L. Zhang⁴, C. Older², G. Waldbieser², M. W. Schilling¹, ¹Department of Food Science, Nutrition and Health Promotion, Mississippi State University, Starkville, Mississippi, United States, ²Warmwater Aquaculture Research Unit, USDA, Stoneville, Mississippi, United States, ³Department of Wildlife, Fisheries and Aquaculture, ⁴Department of Poultry Science, Mississippi State University, Starkville, Mississippi, United States *ovo2333@126.com

Objectives: Catfish fillets undergo spoilage during refrigerated storage, which impacts consumer acceptance and leads to food waste. This research aims to determine if buffered vinegar affects the shelf life of channel (Ictalurus punctatus) and hybrid (♂I. furcatus × ♀I. punctatus) catfish fillets during refrigerated storage.

Materials and Methods: Market-size channel and hybrid catfish (n = 90 each; n = 30/pond) were harvested and filleted. Fillets from each fish were divided into control and vinegar-treated groups, which resulted in 4 treatments: channel control (CC), channel treated with vinegar (CV), hybrid control (HC) and hybrid treated with vinegar (HV). Vinegar-treated fillets were soaked in a 1.5% iced vinegar solution, while control fillets were soaked in iced water for 5 min. Fillets were overwrapped and refrigerated under LED lighting, and were sampled on days 0, 3, 6, and 9. A split-split-plot arrangement (catfish type as the main plot factor, vinegar as the subplot factor, and day as the sub-subplot factor) in a randomized complete block design with 3 replications (ponds) was conducted to evaluate the effect of buffered vinegar on the pH, color, aerobic plate count (APC), and descriptive sensory attributes (n = 8 panelists) of channel and hybrid catfish fillets over refrigerated storage. PROC GLM procedure was used to analyze the data, when differences occurred (P < 0.05), Tukey’s HSD Test was used to separate treatment means.

Results: No differences (P > 0.05) were observed in pH or instrumental color among the 4 treatments throughout storage time. Initially, all 4 treatments showed similar APC levels (P > 0.05) on day 0, ranging from 3.0 to 3.3 log cfu/g. By day 6, HV had lower APC (P < 0.05) than HC, while CV did not differ in APC (P > 0.05) from CC. However, both control samples were considered microbiologically spoiled, with APC exceeding 7 log cfu/g; while both vinegar-treated fillets remained below 7 log cfu/g. By day 9, all treatments had APC counts greater than 7 log cfu/g, with vinegar-treated fillets containing fewer counts (P < 0.05) than control fillets. Sensory analysis suggested all fillets were still acceptable at day 6, with no differences (P > 0.05) observed for any aroma attributes, including fishy, earthy, sour, oxidized, rancid, spoilage, off-notes, and degree of difference (DOD). However, by day 9, HV was rated borderline, CV was borderline/unacceptable, and CC and HC were both unacceptable. Notably, the acceptability of HV fillets on day 9 was comparable (P > 0.05) to that of HC and CC on day 6. Among all samples, HV fillets exhibited the least spoilage-related aroma, followed by CV fillets. By day 9, compared to CC fillets, HV fillets had less (P < 0.05) rancid aroma, spoilage aroma, off-notes, and DOD ratings, while CV had less (P < 0.05) spoilage aroma and DOD ratings. Additionally, HV fillets on day 9 did not differ (P > 0.05) from HV fillets on days 3 and 6 with respect to rancid aroma, off-notes, and DOD ratings; and CV fillets at day 9 was not different (P > 0.05) from CC fillets on day 6.

Conclusion: Vinegar treatment enhanced the microbiological and sensory shelf life of both channel and hybrid catfish fillets, with more pronounced improvement in hybrid catfish. Future research will explore the impact of vinegar treatment on the eating quality of catfish fillets, and investigate the microbial composition and diversity of fillets treated with vinegar over refrigerated storage.

Funding Source: USDA-ARS sponsored project of the MS Center for Enhancing Utilization and Safety of Catfish and Other Aquatic Foods.

Keywords: antimicrobials, refrigeration, sensory analysis, shelf-life

122 EFFICACY OF UTILIZING MEAT EXUDATE FOR DETERMINING MUSCLE-SPECIFIC MICROBIAL CHANGES UNDER SPOILAGE CONDITIONS

M. U. Abdelhaseib ^1,*, J. Seo ¹, Y. H. B. Kim ¹, ¹Animal Sciences, Purdue University, West Lafayette, Indiana, United States *maha@purdue.edu

Objectives: Microbial spoilage of muscle foods remains a significant challenge for the US meat industry. Spoilage is a complex process driven by the growth of spoilage bacteria, which contribute to off-odor and off-flavor, key factors determining the shelf-life of fresh meat. Thus, rapid detection and/or prediction of microbial spoilage of fresh meat is considerably beneficial for the meat industry. While meat exudate holds promise as an analytical matrix for spoilage detection, its efficacy has not been fully evaluated. The objective of this study was to establish the temporal microbial changes occurring during muscle-specific aging under spoilage conditions, utilizing meat exudate microbial analysis.

Materials and Methods: Pairs of 3 muscles, including Infraspinatus (IF), Semimembranosus (SM), and Longissimus lumborum (LL), from 15 beef carcasses (USDA Choice) were collected at 1 d postmortem. Each muscle pair divided into eight equal section, vacuum-packaged, and randomly assigned to either 1°C (control) or 10°C (spoilage) treatment for 1, 14, 21, and 35 d of aging periods. Upon aging, meat exudate and tissue samples were aseptically collected for microbial analysis, including aerobic plate count (APC) and lactic acid bacteria (LAB). Steak from each aging time for display color were measured under the light for 7 d. The experimental design was split-plot with carcass serving as the blocking factor. All data were analyzed using PROC GLIMMIX of SAS9.4. Least-squares means for all traits were separated using the Tukey test (P < 0.05) with the LINES option.

Results: The display color was significantly affected by the storage conditions and muscle types. In brief, a*, b*, and chroma of all beef samples decreased over aging time (P < 0.05), while the IF muscle showed most discoloration (indicated by lower a* and higher hue angle values) when exposed to 10°C, followed by SM, and LL showing the least discoloration (P < 0.05). There was a significant interaction between storage temperature and storage time in microbial results for both APC and LAB when measured from both exudate and tissue samples. No muscle effect, however, was observed in APC and LAB counts. In general, the microbial results in both muscle tissue and exudate showed the similar pattern, where exposing beef samples at 10°C significantly increased the microbial counts with extended aging times. However, a slight increase (around 1–2 logs in APC and LAB, respectively) in microbial counts was observed in the exudate compared to the meat tissue, regardless of storage times and muscle types, indicating elevated sensitivity detecting microbial counts in meat exudate for meat freshness.

Conclusion: The results from this study indicate the feasibility of utilizing exudate microbial analysis as a medium for detecting spoilage of different beef muscles. Further research conducting metabolomics and proteomics profiling along with metagenomics for both exudate and muscle tissue is currently underway to identify potential biomarkers related to spoilage of beef muscles.

Funding Source: USDA-NIFA AFRI grant (2022-09199).

Keywords: aerobic plate count, beef spoilage, meat exudate, microbial analysis

123 EVALUATING THE IMPACT OF VARIOUS DRY-AGING METHODS ON QUALITY ATTRIBUTES OF BISON LOINS

M. Romanyk^1,*, D.-J. Shin¹, J.-K. Seo¹, S. Rehman¹, B. Kim¹, A. Blair², J. K. Grubbs², ¹Animal Sciences, Purdue University, West Lafayette, Indiana, United States, ²Animal Science, South Dakota State, Brookings, South Dakota, United States *mromanyk@purdue.edu

Objectives: Bison meat products have garnered consumer interest as healthier, leaner alternatives to traditional beef. Yet, there lacks sufficient research regarding bison meat quality especially concerning postmortem aging. Dry-aging has been considered as a value-adding process due to the development of a unique flavor profile. However, there is little to no published information on how dry-aging affects the final yield, oxidative stability, and quality attributes of bison loins. Furthermore, given the availability of various dry-aging methods in the commercial market, comparing different dry-aging methods and their impacts on meat quality would provide practical information for the bison industry. Therefore, the purpose of this study was to evaluate the effect of various dry-aging methods on the final yield, oxidative stability, and quality attributes of bison loins.

Materials and Methods: Paired bone-in loins (M. Longissimus lumborum) were received at 7 d postmortem from grass-finished bison carcasses (n = 15). The pairs were each divided in half and randomly assigned one of 4 aging treatments: wet-aging (WA), dry-aging (DA), dry-aging in water-permeable bag (DWA), and dry-aging under UV light exposure (UDA). Dry aging treatments were placed on racks in a 1–2°C cooler with 65% humidity and 0.7 m/s airflow. UDA were exposed twice a day to UV light for 5 min exposures. After aging for 28 d, the sections were deboned, trimmed, and weighed to determine the final saleable yield. Steaks (2.54 cm) were used for pH measurement, initial color (CIE L*a*b*), Warner-Bratzler shear force (WBSF), myofibrillar fragmentation index (MFI), and thiobarbituric acid reactive substance (TBARS) analyses. A consumer sensory panel (n = 90) was also conducted. The experimental design was a split-plot design. A PROC GLIMMIX procedure of SAS with a significance level of P < 0.05 was used to analyze all data.

Results: After aging, WA had significantly higher saleable yields compared to the dry-aging treatments due to its lower shrink/purge loss and no trim loss (P < 0.05). In fact, each dry-aging method resulted in around 47% total loss. Among dry-aging treatments, DWA resulted in a significantly lower shrink loss than DA, while DWA had a higher trim loss compared to that of DA (P < 0.05). UDA had intermediate values of the losses between DA and DWA but was not significantly different from either. There was no difference between pH values between aging methods (P > 0.05). No significant differences in MFI and WBSF values, or sensory tenderness liking existed between the treatments following the aging time. TBARS analysis revealed higher lipid oxidation in UDA treatments, followed by DA. However, DA did not statistically differ in TBARS value from DWA treatments. The consumer sensory panel found DWA and UDA to have significantly higher flavor liking compared to WA.

Conclusion: Regardless of treatment, no differences in pH, WBSF, MFI, and tenderness liking were found, suggesting that dry-aging does not affect tenderness differently than traditional wet-aging. Furthermore, dry-aging results in considerable loss in saleable yield compared to WA but can improve overall flavor of bison loins. Interestingly, UDA had higher TBARS values which could propose that UV light induces more lipid oxidation. This warrants future research to identify compounds associated with dry-aging as well as microbial and chemical analyses to validate its impact on flavor characteristics.

Funding Source: This project is funded by the Center of Excellence for Bison Studies.

Keywords: bison, dry-aging, meat quality, moisture permeable packaging, ultraviolet

124 INFLUENCE OF CARCASS VASCULAR RINSING WITH CALCIUM CHLORIDE ON NON-ELECTRICALLY STIMULATED AND STIMULATED CARCASSES ON MEAT QUALITY OF LAMBS

A. J. Franzen^1,*, N. Pharino¹, K. Hwang¹, R. E. Campbell², J. R. Claus¹, ¹Animal & Dairy Sciences, University of Wisconsin-Madison, Madison, Wisconsin, United States, ²Technical Services, MPSC Inc., Hudson, Wisconsin, United States *adamfranzen62@gmail.com

Objectives: The study objective was to determine the effects of vascular rinsing non-electrically stimulated and stimulated carcasses with a calcium chloride solution on lamb meat quality.

Materials and Methods: Infusing calcium chloride into carcasses before rigor mortis presents an opportunity to enhance meat quality and tenderness. The study was conducted over 3 different trial periods with lambs (n = 40) which consisted of various breeds (commercial crossbred, Dorset, Hampshire, Suffolk, Polypay, Southdown), age (6–9 mo), and live body weight (59.42 ± 29.48 kg). Lambs were randomly assigned to 3 vascular rinse treatments (TRT) that included: (RC = Rinse & Chill® solution; saccharides, phosphates), (CA = 0.3M CaCl₂ + RC), (ES-CA = electrical stimulation, 800mA current, peak 350V for 60 s, followed by CA). Animals were stunned by penetrating captive bolt. The vascular rinsing process entailed inserting a catheter into the heart and rinsing the carcass at 10% of its body weight. The treatments were applied to the carcass immediately upon exsanguination. Carcasses were skinned, eviscerated, and chilled (3°C, 24 h). Carcass temperature and pH were recorded (semimembranosus, SM) from 1 h to 20 h postmortem (PM). At 24 h PM, the longissimus dorsi (LD), SM, and triceps brachii (TB) were excised, vacuum packaged, or overwrapped in oxygen-permeable film. Color measurements (CIE L*, CIE a*, chemical states of myoglobin) were determined during storage (3 and 7 d) PM. Purge, Warner-Bratzler shear force (WBS), and cook loss (3 and 7 d) PM; at 68.3°C internal, LD, SM, and TB were also determined. Animal served as the experimental unit. Data were analyzed as a split-split plot design (whole plot, TRT; split, muscle; split-split, day) with means (P < 0.05) separated using PROC MIXED (SAS Institute).

Results: Live animal weights were not different (P > 0.05) among the treatments. Hot carcass weights were not different (P > 0.05) among the treatments. For carcass pH, the ES-Ca treatment was lower (P < 0.05) than the Ca and RC treatments, while Ca was lower (P < 0.05) than the RC treatment. The RC treatment had greater CIE L*, CIE a*, Chroma C, and oxymyoglobin, and lower values for metmyoglobin (P < 0.05). The SM muscle had lower CIE L* (P < 0.05) than the LD and TB muscles. At day 3 PM, CIE a* was lower (P < 0.05) in the LD muscle compared to TB and SM. On day 7 PM, CIE a* was higher (P < 0.05) in the TB muscle compared to LD and SM. RC had the least (P < 0.05) purge in the LD and SM muscles. RC had lower (P < 0.05) cook loss than ES-CA. The LD in CA and ES-CA had lower (P < 0.05) WBS than RC. With ES-CA, the SM exhibited the lowest (P < 0.05) WBS. RC had the greatest WBS at day 3 (P < 0.05), with no differences (P > 0.05) found between TRT on day 7.

Conclusion: The implications of vascularly delivering calcium chloride throughout the carcass on meat quality are noteworthy, particularly shear force reduction, suggesting the potential to enhance tenderness. More rapid chilling to reduce the effect of the rapid drop in pH may benefit meat color and moisture retention.

Funding Source: University of Wisconsin and MPSC Inc.

Keywords: calcium chloride, carcass vascular rinsing, electrical stimulation, lamb, meat quality

125 SOUS VIDE COOKERY METHODS OF VARYING TEMPERATURES AND TIMES TO ASSESS PALATABILITY OF BEEF ROUND MUSCLES OF THREE QUALITY DESIGNATIONS

M. K. Phillips^1,*, C. L. Gifford¹, ¹Department of Animal Science, University of Wyoming, Laramie, Wyoming, United States *cody.gifford@uwyo.edu

Objectives: The objective of this study was to evaluate sensory attributes and objective tenderness of steaks from the beef semimembranosus, biceps femoris, semitendinosus, and vastus lateralis cooked using 6 time-temperature sous vide cookery combinations.

Materials and Methods: Beef subprimals (N = 120; n = 10/individual subprimal of each quality designation: Top Choice [USDA average and high Choice], USDA Choice, and USDA Select) were purchased from a commercial beef processor and wet aged for 28 d at 0–4°C before fabricating into 2.54-cm-thick steaks and frozen. Randomized, thawed (0–4°C for 24–48 h) steaks assigned to sensory evaluation were vacuum packaged in high temperature rated bags and cooked for either 3 h or 24 h in water baths pre-heated to 60°C, 71°C, or 77°C. Trained panelists rated descriptive sensory attributes on a continuous line scale. Steaks designated for tenderness evaluation were thawed and cooked in the exact same manner prior to Warner-Bratzler (WBSF) and slice (SSF) shear force measurement. Data for each muscle were analyzed independently. Models included the fixed effects of cooking duration, water bath temperature and their interaction with USDA quality grade category included as a block. Random effects included panel (sensory) or cook date (shear force) with peak cooked temperature included as a covariate. Data were analyzed using the lmer package in R statistical software. Means were separated at α < 0.05 using the emmeans function.

Results: There was an interaction between cooking duration and water bath temperature that impacted sensory tenderness, juiciness, and percent fragmentation for all muscles (P < 0.001). Biceps femoris, semimembranosus and semitendinosus steaks cooked in 71°C and 77°C water baths were more tender when cooked for 24 h than 3 h. All steaks cooked in 60°C water baths were less juicy when cooked for 24 h compared to 3 h. Biceps femoris and semitendinosus steaks cooked for 24 h in 71°C or 77°C water baths were more fragmented than all other steaks. There was an interaction between cooking duration and water bath temperature that affected SSF and WBSF for biceps femoris and semitendinosus steaks (P < 0.04). There was an interaction between cooking duration and water bath temperature that impacted umami, liver, and bloody/serumy flavors for the vastus lateralis and biceps femoris steaks (P < 0.05). Semimembranosus and vastus lateralis steaks were objectively more tender when cooked for 24 h versus 3 h (P < 0.001). Cooking duration and water temperature had no impact on sour ratings among all muscles. Browned/roasted ratings were more intense in semimembranosus, biceps femoris, and vastus lateralis steaks cooked for longer durations (P < 0.03).

Conclusion: Long duration sous vide cooking improved tenderness for steaks of the beef round, particularly steaks from the biceps femoris, semimembranosus and semitendinosus. Namely, increasing the cooking duration from 3 h to 24 h for steaks cooked in sous vide water baths set to 71°C and 77°C improved tenderness while maintaining juiciness. Conversely, steaks cooked in water baths set at 60°C did not improve tenderness and were drier with extended cooking.

Funding Source: Funded by the Wyoming Beef Council.

Keywords: beef, sous vide, palatability

126 IMPACT OF LIGHTING SOURCE AND DISPLAY DURATION ON SHELF-LIFE CHARACTERISTICS OF VACUUM ROLL STOCK PACKAGED GROUND BEEF

J. W. Gillespie^1,*, M. P. Myer¹, D. K. Dittoe¹, C. L. Gifford¹, ¹Department of Animal Science, University of Wyoming, Laramie, Wyoming, United States *cody.gifford@uwyo.edu

Objectives: The objective of this study was to evaluate the effects of continuous light emitting diode (LED) and fluorescent (F) light source, 12 h of intermittent LED and F followed by 12 h of dark storage, and dark storage on shelf-life characteristics of two different blends of vacuum packaged ground beef in a simulated retail display. Packages were displayed beyond the typical shelf-life period.

Materials and Methods: Shelf-life characteristics of vacuum roll stock ground beef packages collected from a commercial processor (n = 125/ground beef blend of 80:20 and 75:25) were assessed in a simulated retail display (0.4 ± 0.4°C) over a 28-d period during 2 independent pilot experiments (2 ground beef blends). During both independent experiments, ground beef packages were displayed under 5 different light source conditions: constant fluorescent (average LUX = 2,494), intermittent fluorescent (12 h light – 12 h dark; average LUX = 2,241), constant light emitting diode (LED; average LUX=1,826), intermittent LED (12 hr. light – 12 hr. dark; average LUX = 1,840), and complete dark storage. On d 0, 7, 14, 21, and 28, objective color measurements (L*, a*, b*) of intact packages were recorded using a Hunter MiniScan EZ 4500 Portable Spectrophotometer (45°/0°). After packages were aseptically opened on d 0, 7, 14, 21, and 28, samples (25 g) were collected for microbial spoilage determination and remaining sample was allowed to oxygenate (bloom) for ∼30 min prior to recording objective color measurements as described previously. The microbial sample was homogenized in buffered peptone water (25 g:225 mL) in sterile filter sample bags for 2 min at 200 rpm and duplicate 10 g samples were used for pH analysis. Homogenates were serially diluted in 0.1% Peptone, pour and dot plated on respective media, and incubated to assess total aerobic and anaerobic mesophilic bacteria, total psychrotrophic bacteria, total Enterobacteriaceae, total lactic acid-producing bacteria, and total Pseudomonas. Remaining ground beef sample from each package was vacuum packaged and stored < −20°C. Microbial spoilage indicator plate counts were calculated as CFU/g of ground meat and Log transformed prior to statistical analysis. The lmer package in R statistical software (version 4.3.1, R Core Team) was used to analyze the fixed effects of lighting type, day of display and their interaction, and pairwise comparisons were determined using the emmeans function for both independent experiments.

Results: The interaction between light source and display day was significant (P ≤ 0.05) for L* and a* objective color measurements for both vacuum packaged and bloomed ground beef in both experiments. Similarly, a significant interaction (P ≤ 0.05) between light source treatment and display day was observed for all microbial spoilage indicators in both independent ground beef experiments, except for Pseudomonas in experiment 2. The main effect of Pseudomonas (Log CFU/g) increased throughout the retail display during experiment 2 (P ≤ 0.05; higher fat blend). In experiment 2, higher (P ≤ 0.05) levels of aerobic and anaerobic mesophiles (Log CFU/g) were observed among ground beef displayed under Intermittent LED and Constant LED light sources after 7 d of display; however, no differences in microbial growth existed between LED treatments and dark storage at 14 d of display.

Conclusion: The combination of lighting source and increasing display time impacted objective color measurements of packaged and bloomed ground beef in experiment 1 (80:20 ground beef blend) and experiment 2 (75:25 ground beef blend). Except for Pseudomonas, these factors (lighting source × day of display) increased all other microbial growth indicators over the display period in both experiments.

Funding Source: Funded in part by the University of Wyoming and private industry.

Keywords: shelf-life characteristics, ground beef

127 COMPARISON OF DATA FROM THE USDA FOOD COMPOSITION DATABASE AND LEVEL OF PROCESSING IN THE NOVA CLASSIFICATION SYSTEM

S. E. Raber^1,*, C. L. Gifford¹, ¹Department of Animal Science, University of Wyoming, Laramie, Wyoming, United States *cody.gifford@uwyo.edu

Objectives: The NOVA food classification system was intended to categorize foods based on the current version of level of processing during manufacture or preparation. This classification consists of group 1 (unprocessed or minimally processed), group 2 (processed culinary ingredients), group 3 (processed foods) or group 4 (ultra-processed). Group 1 is considered unprocessed/minimally processed and group 4 is considered ultra-processed. Although the American Meat Science Association Lexicon defines minimally products as “raw, uncooked meat products reduced in size by fabrication, mincing, or grinding”, ground products remain inconsistently categorized in more processed NOVA classification groups. Currently, pre-prepared burgers are classified as an ultra-processed food. The objective of this study was to evaluate whether nutrient data from meat products in the USDA Food Composition Database are aligned with current NOVA classification groups applied to meat to better evaluate the effectiveness of NOVA classification as a tool to assess food processing and diet quality.

Materials and Methods: Publicly accessible, comprehensive nutrient data were utilized from the USDA Food Composition Database for this pilot study. Data consisting of all minerals, vitamins, fatty acids, cholesterol, protein and total fat were compiled for raw and cooked meat and poultry products, ground meat consisting of various formulations, and processed meat and poultry products. The FactoMineR package in R Statistical Software (version 4.3.3; R Core Team) was used to develop principal component analysis models using mean centered and scaled nutrient data from full meat and poultry products and products sharing a common factor (i.e., raw beef). Hierarchical cluster analysis (HCA) was performed on the first two principal components to identify clusters of products. Additional predictive models were assessed using larger and subset nutrient data to assess the predictability of NOVA classification, HCA cluster assignment, criteria of meat products (i.e., species, cooked status, processing level according to the AMSA lexicon).

Results: Results presented focus on ground beef and fresh beef cuts. The first two principal components explained 65% of the variability in the complete nutrient data consisting of raw ground beef formulations and fresh raw beef cuts from the USDA Food Composition Database. Models utilizing complete nutrient data and models including only fatty acid or only micronutrient data revealed similar principal component analysis results for these beef products. Results of HCA produced a high fat ground beef cluster and a cluster of lower fat ground beef products combined with selected, raw choice and select chuck cuts. Other raw beef cuts were clustered similarly around lower fat raw ground beef (90:10 or leaner).

Conclusion: Although the NOVA Classification System was developed to categorize foods based on level of processing to further evaluate the link between processed foods and diet quality, nutrient data profiles of meat products may not align with this classification system. Multivariate approaches in this study did not isolate single ingredient minimally processed products from ground products.

Keywords: nutrient profile

128 ASSESSMENT OF WOODY BREAST CONDITION IN BROILER BREAST FILLETS USING SINUSOIDAL ILLUMINATION IMAGING

J. Cai^1,*, Y. Lu¹, ¹Biosystems & Agricultural Engineering, Michigan State University, East Lansing, Michigan, United States *luyuzhen@msu.edu

Objectives: Muscular myopathies such as woody breast (WB) impair the quality and marketability of poultry products, leading to significant economic losses for poultry industries worldwide. WB-affected broiler breast fillets are characterized by abnormal tissue hardness, overall muscle rigidity, and irregular shape profiles. Manual evaluation based on tactile palpation and visual examination is the current practice for WB assessment at poultry processing facilities, but it is subjective, labor-intensive, and may induce contamination due to physical contact. Sinusoidal illumination reflectance imaging (SIRI) has recently emerged as a new optical imaging modality, as opposed to conventional uniform illumination-based imaging, for enhanced food quality assessment due to its capabilities of depth-resolved tissue characterization and three-dimensional (3-D) surface reconstruction. This study is a novel effort to investigate the applicability of SIRI, coupled with phase-measuring profilometry, for improved assessment of WB in broiler meat.

Materials and Methods: Images were acquired for a collection of boneless chicken fillets of different categories, i.e., “Normal (no WB)”, “Moderate”, and “Severe”, based on the severity of WB, by an in-house assembled benchtop broadband structured-illumination reflectance imaging (SIRI) platform under phase-shifted sinusoidal illumination at spatial frequencies of 0.0150 to 0.150 cycles/mm. Acquired pattern images at each spatial frequency were demodulated into 1) two intensity images of Direct Component (DC) and Amplitude Component (AC) and 2) one phase-difference image depicting sample surface profiles. Textural features were extracted from DC and AC images at different spatial frequencies using the pre-trained ResNext-101 model, while hand-crafted geometric features were extracted from the surface profile, and then the extracted features were utilized for classification modeling with regularized linear discriminant analysis (RLDA) to differentiate the poultry samples according to WB conditions.

Results: AC images offered an enhanced characterization of the surface textures over chicken samples compared to DC images, while phase-difference images provided surface profiling of the geometry. With only texture features extracted from AC and DC images, the classification model showed limited capacities for differentiating between normal and WB affected samples, yielding an overall classification accuracy of 74.63% with 10 modeling replications. The inclusion of geometric features resulted in a higher accuracy of 84.74%, representing a statistically significant improvement of 10.11% (P < 0.05) over the accuracy (74.63%) by the corresponding surface features.

Conclusion: This study demonstrates that geometric features are useful for imaging-based, non-invasive assessment of WB conditions and that the SIRI technique holds promise for enhanced quality assessment in chicken meat. Further research is to develop a real-time SIRI system for online poultry quality detection.

Funding Source: This research was supported by the US Department of Agriculture, National Institute of Food and Agriculture (Grant No. 2022–67018-36625) and Michigan Alliance for Animal Agriculture.

Keywords: machine learning, phase analysis, poultry, structured illumination, woody breast

129 INFLUENCE OF 24-HOUR PH CLASSIFICATION ON POSTMORTEM PROTEIN DEGRADATION AND FRESH PORK LOIN QUALITY

C. Jess^1,*, K. Prusa², L. Reever², L. Johnson¹, J. Stowater¹, E. Huff-Lonergan¹, S. Lonergan¹, ¹Department of Animal Science, ²Department of Food Science and Human Nutrition, Iowa State University, Ames, Iowa, United States *cjess@iastate.edu

Objectives: The ability to predict fresh pork quality through discovery of differences in postmortem protein changes could help address the variation in quality that continues to be observed in fresh pork products. Therefore, this project aimed to advance the understanding of how postmortem pH variation affects quality, sensory, and biochemical attributes of fresh pork loin and how early postmortem pH impacts the abundance of desmin degradation products within the sarcoplasmic fraction of muscle.

Materials and Methods: Fresh pork loins (N = 50) were selected from a production line of a commercial facility at 1 d postmortem. The product was sorted by 1 d postmortem pH into low/normal (L; n = 25, 5.59 to 5.71) and high/normal (H; n = 25, 5.90 to 6.46) categories. Loins were vacuum packaged and immediately transported on ice to the Iowa State University Meat Laboratory. All loins were cut into 2.54 cm or 0.635 cm thick chops and trimmed of external fat and connective tissue. Subjective color and marbling scores were assigned. A Minolta chroma meter was used to collect Hunter L, a, and b values. Drip loss of 1 d chops was measured over 24 h. The remaining loin chops were vacuum packaged per aging time, aged for 1,7, or 14 d (4°C), and then frozen until analysis. Two chops from each loin were used to measure cook loss and sensory characteristics. Off-flavor, pork flavor, juiciness, tenderness, and chewiness were evaluated by a trained panel of (n = 3) on a 10-point scale. An Instron fitted with a star probe attachment was used to measure instrumental tenderness of cooked chops. Frozen, homogenized longissimus dorsi (LD) was used to determine lipid and moisture content. For desmin degradation, proteins from the LD were extracted in a low ionic strength buffer (50 mM Tris-HCl and 1 mM ethylenediaminetetraacetic acid [pH 8.0]), and desmin degradation products in the sarcoplasmic fraction were determined using western blotting. All data were analyzed using R v 4.2.1 for ANOVA to determine the effect of pH classification, compute least-squares means, and for Tukey’s mean differences. Analysis of sensory panel data included panelist as a random effect in the model.

Results: Loin chops from the H group had 78% less drip loss at day 1, and approximately 18% less cook loss than chops from the L group at all aging times. H chops had lower star probe values than L chops at days 1, 7, and 14. H chops exhibited higher color scores than L chops at day 1 (4 vs. 3) and day 14 (3 vs. 2). There was no significant difference in intramuscular lipid content (P = 0.37). The trained panel determined juiciness, tenderness, and pork flavor were greater within H chops whereas off-flavor and chewiness were higher within L chops at day 14. The abundance of degraded desmin in the soluble fraction was significantly greater in H chops (P < 0.0001) at 1,7, and 14 d postmortem.

Conclusion: Higher pH at 1 d postmortem resulted in conditions that generated more desmin degradation, which is proposed to result in improved tenderness and water-holding capacity. Variation in postmortem pH indeed has significant effects on quality attributes such as tenderness, cook loss, and palatability. The results of this study support 24 h postmortem pH as a viable predictor of value in pork products.

Funding Source: Partial funding was provided from the Iowa Agricultural and Home Economics Experiment Station project no. IOW04121 and the Iowa Pork Producers Association.

Keywords: desmin, fresh pork quality, pH

130 MUSTARD EXTRACT COMBINED WITH ROSEMARY EXTRACT DELAYS LIPID OXIDATION IN BEEF PATTIES

C. Shaw^1,*, M. Wootton¹, Y. Guo¹, J. Van Buren¹, T. Goertzen¹, P. Ebrahimi¹, J. Nasados¹, P. Bass¹, J. Lancaster², I. Popova³, M. Colle¹, ¹Animal, Veterinary and Food Science, University of Idaho, Moscow, Idaho, United States, ²Centennial, National Cattlemen’s Beef Association, Colorado, United States, ³Soil Science, University of Wisconsin-Madison, Madison, Wisconsin, United States *cshaw@uidaho.edu

Objectives: Utilization of natural, plant-based water binders could improve the shelf life of beef patties, thereby reducing food waste. The objective was to optimize the mustard meal extract synergistic effect when combined with rosemary extract to improve shelf-stability and physical appearance of fresh beef patties.

Materials and Methods: Treatments included 1.0% mustard extract and 1.0% rosemary extract (M1), 0.25% mustard extract and 1.0% rosemary extract (M2), rosemary extract at 1.0% (positive control; R), and no binder (negative control; C). The effect of independent mustard extract at different levels was examined in previous research by the authors, thus not included in the current study. Six batches of each treatment were made with USDA Choice chuck roll at the University of Idaho Meat Lab with beef (< 30 mo of age) purchased from a commercial processor. Subprimals were coarse ground (10 mm) and fine ground (3 mm). Each batch was mixed for 2.5 min at 29 rpm in a DMX 50 mixer and then formed using a Patty-O-Matic 330A patty former into 16mm-thick patties (85:15 lean: fat) weighing 151g each. Two patties from each batch were analyzed for each parameter: pH, purge loss, lipid oxidation, objective color, and subjective color. pH and lipid oxidation were measured on day 0 (d 0) and day 4 (d 4) of retail display. Patties were weighed on d 0 and d 4 of the retail display to calculate retail purge loss. Objective color (L*, a*, b*) and subjective color (Ground Product Display Discoloration, scored 1 to 8) were evaluated each day of retail display. Data was analyzed using SAS (9.4) software. In this factorial design batches were the experimental unit. Data was analyzed using a mixed model analysis of variance with retail display time assumed as a fixed effect and considered a repeated measure. Significance was determined at P < 0.05.

Results: There was no interaction between day of retail display and antioxidant treatments for pH (P = 0.314); however, there was a main effect of day of retail display (P < 0.001), where pH increased from d 0 to d 4 for all treatments. There was no difference between treatments for retail purge loss (P = 0.304). All antioxidant treatments reduced lipid oxidation compared to C (P < 0.001), extending lipid oxidation shelf life to 4 d. M1 displayed the lowest a* value on d 4 (P < 0.001) and the most subjective discoloration on d 4 (P = 0.001) thereby having the shortest color shelf life. Of mustard treatments, M2 displayed a longer color shelf life. Both L* and b* had a main effect of day (P = 0.008, P < 0.001) respectively, and a main effect of antioxidant treatment (P = 0.039, P = 0.001) respectively. C displayed a lower L* value indicating a darker color. Whereas M1, M2, and the C patties had a lower b * indicating a less yellow color.

Conclusion: Adding natural, plant-based antioxidants to fresh beef patties delayed oxidation during retail display, improving shelf life. Interestingly, patties treated with equal parts mustard and rosemary extract produced the most retail discoloration. Using antioxidation in fresh beef patties to improve shelf life could reduce food waste in the US. Future research can involve sensory evaluation.

Funding Source: This study was funded by USDA NIFA (National Institute of Food and Agriculture; #AW613).

Keywords: fresh beef patties, antioxidant, shelf life, mustard extract, rosemary extract, lipid oxidation

131 SIMPLIFIED SLICE SHEAR FORCE PROCEDURE FOR BEEF GLUTEUS MEDIUS STEAKS

S. D. Shackelford^1,*, S. Bludau¹, D. A. King¹, T. L. Wheeler¹, ¹USMARC, USDA-ARS, Clay Center, Nebraska, United States *steven.shackelford@usda.gov

Objectives: To develop a simplified slice shear force (SSF) procedure for beef gluteus medius steaks and to compare that procedure to the traditional SSF procedure. The traditional SSF procedure had been shown to be more repeatable than Warner-Bratzler shear force for beef gluteus medius. But it was difficult to implement because the steps of the procedure differed depending on which side of the carcass the steak came from. That is, to sample parallel to the muscle fibers, you had to know if the steak was from the left or the right side of a beef carcass. For the simplified SSF procedure, slices were sampled perpendicular to the cut surface of the steak. That is, the simplified procedure is the same for steaks from either side of the carcass. Moreover, sampling perpendicular to the cut surface of the steak allows for obtaining more slices per steak. Whereas the traditional SSF procedure involved sampling and shearing 3 slices per steak, the simplified SSF procedure includes sampling and shearing 6 slices per steak.

Materials and Methods: USDA Choice Angus beef carcasses (n = 28) were selected in a large-scale Midwestern beef packing plant. The individually identified 184 Top Sirloin was obtained from both sides of each carcass. Cuts from one-half of the carcasses were assigned to be minimally aged and cuts from one-half of the carcasses were assigned to a traditional aging period to increase the chance of having adequate variation in tenderness. Muscles from one side of each carcass were assigned to be sample with traditional SSF and muscles from the other side of each carcass were assigned to be sample with simplified SSF. The center-cut top sirloin (gluteus medius) was sliced into steaks. Steaks were numbered 1 through 6 from posterior to anterior. Steak 1 consists of heavy connective tissue from the round-loin juncture and was not suitable for SSF testing with either procedure. Steak 6 was not suitable for traditional SSF. At the appropriate time postmortem (6 or 20 d postmortem), fresh (never frozen) steaks were cooked and traditional SSF was measured on steaks 2, 3, 4, and 5 and simplified SSF was measured on steaks 2, 3, 4, 5, and 6. Means were compare with the GLM procedure and correlation coefficients were compared with the CORR procedure of SAS.

Results: The traditional and simplified SSF procedures did not differ in mean SSF (P = 0.78; 19.95 and 19.61 kg for traditional and simplified procedures, respectively). The correlation coefficient of traditional and simplified SSF among adjacent steak locations is shown in Table 1. Across each pair of adjacent steak locations, the correlation coefficient was highly significant for traditional and simplified SSF (P < 0.0001). Also, across each pair of adjacent steak locations, the correlation coefficient was the same or slightly stronger for the simplified SSF procedure.

Conclusion: The simplified gluteus medius SSF procedure is easier to adopt and more robust than the traditional SSF procedure with no impact on the mean SSF value. This should facilitate more widespread use of SSF for gluteus medius tenderness research.

Funding Source: USDA-ARS

Keywords: beef, slice shear force, tenderness

132 ASSESSING CONCENTRATIONS OF ALPHA-GAL IN STRIP LOINS AT VARYING DEGREES OF DONENESS

J. Kress^1,*, J. T. Looper¹, S. Hene¹, T. O’Quinn¹, E. Beyer², M. Chao¹, ¹Department of Animal Sciences and Industry, Kansas State University, Manhattan, Kansas, United States, ²Department of Animal Sciences, North Dakota State University, Fargo, North Dakota, United States *mdchao@ksu.edu

Objectives: Galactose-α-1,3-galactose, otherwise known as alpha-gal, is a carbohydrate bound to proteins and lipids found in all non-primate mammals. Alpha-gal syndrome (AGS), also known as red meat allergy, is an allergic reaction to alpha-gal triggered by tick bites from Lone Star ticks. Symptoms from AGS patients typically appear 2 to 6 h after ingestion of food items containing mammalian tissues, ranging from itchy skin to lethal anaphylaxis. However, very little research has been conducted on the severity of allergic reactions based on the alpha-gal content in the food nor if heat can help reduce alpha-gal content in food. Therefore, the objective of this study is to quantify concentrations of alpha-gal in striploin steaks under varying degrees of doneness to establish alpha-gal content in beef to understand if cooking is an effective way to reduce/remove alpha-gal in red meat.

Materials and Methods: Beef strip loins (n = 10) from 10 different animals were collected at a midwest beef processing plant and brought to Kansas State University for processing. The strip loins were either left uncooked or cooked to 54°C, 60°C, or 77°C. The samples were used to measure proximate analysis and alpha-gal concentration through western blot. For the alpha-gal concentration measurement, whole muscle proteins were extracted and adjusted to a concentration of 2 mg/mL. For each gel, one lane was loaded with alpha-gal conjugated Human Serum Albumin (HSA) as the standard (370 pmol alpha-gal/μg HSA). The concentration of alpha-gal in each sample was calculated by the ratio of the alpha-gal density between the sample and standard, then divided by the amount of protein loaded. All alpha-gal concentration is expressed as pmol/μg protein.

Results: As expected, the moisture percentage decreased (P < 0.01) and protein percentage increased (P < 0.01) as the degree of doneness of steaks increased from uncooked to 77°C. Interestingly, the concentration of alpha-gal increased as the degree of doneness increased (P < 0.01), with the lowest concentration in uncooked samples (10.30 pmol/μg protein), followed by 54°C and 60°C (13.56 and 13.85 pmol/μg protein, respectively), with the highest concentration in strip loins cooked to 77°C (16.31 pmol/μg protein).

Conclusion: This is the first known study to establish alpha-gal content in cooked beef. These results showed that a higher degree of doneness in striploin steaks resulted in higher protein and alpha-gal concentrations. It was speculated that alpha-gal concentration increased due to protein denaturation and aggregation during cooking, causing alpha-gal on the proteins aggregate as well. The data suggested that cooking is an ineffective means of removing alpha-gal. Determining the concentrations of alpha-gal in different food items can help AGS patients know what products they can and cannot ingest in order to prevent an allergic response. Therefore, future research should focus on quantifying the alpha-gal content in various food items that could pose a risk to AGS patients.

Keywords: alpha-gal, proximate analysis, strip loin, tick, western blot

133 AN ORDINAL LOOK ON BEEF SUBJECTIVE COLOR AND BEYOND

Y. Guo^1,*, J. Piaskowski², P. Bass¹, M. Colle¹, ¹Department of Animal, Veterinary and Food Sciences, ²College of Agricultural and Life Science, University of Idaho, Moscow, Idaho, United States *yufeig@uidaho.edu

Objectives: Color is one of the most important parameters regarding fresh beef quality. Trained subjective color panels are commonly used to evaluate color traits. Although the evaluation uses a numeric scale, these numbers are ordered categories. These experiments are often analyzed as continuous data using metric models. Such approaches are incorrect due to violations of model assumptions of normality and equal variance from severe class imbalance, resulting in type I and II errors. Ordinal models are a common statistical method for analyzing ordinal data such as panel ratings. This study contrasts how subjective color results change due to using statistically sound ordinal models compared to metric models.

Materials and Methods: Three sets of beef subjective color data from 3 studies with multi-way factorial using RCBD designs were used. Trained evaluators rated beef steaks to examine the impacts of retail display time and treatments on oxygenated lean color, amount of browning (B), discoloration, surface discoloration (S), and color uniformity. Retail day (data 1, 2, 3), muscle location (data 1), and treatment (data 1, 2, 3) were fixed effects; animal (data 1) or primal (data 2 and 3) were random effects in both metric and ordinal models. The metric models used data aggregated across evaluators following the American Meat Science Association Meat Color Guidelines and were analyzed using a mixed linear model. An autoregressive order 1 correlation structure was included to account for repeated measures of day. The ordinal models used unaggregated data where the evaluator was included as an additional random effect. No repeated measures component was included for the ordinal models as ordinal models do not assume data independence. All main effects and interactions were evaluated for all models. The {nlme} and {ordinal} packages were used to perform metric and ordinal analyses, respectively. All analyses were performed in R v4.3.

Results: Exploratory plots found data to be highly skewed indicating metric models as a poor fit. In addition, evaluator variance was not 0, and data aggregation resulted in illegitimate reduction of variance. Both type I and II errors were found when comparing results obtained from the 2 models. An example of type I error was B (data 2) where the metric model detected a day × treatment interaction (P = 0.043), whereas the ordinal model did not find this. S (data 1) was an example of type II error where the metric model only detected retail day (P < 0.001) to be significant whereas the ordinal model captured the significant impacts of both retail day (P < 0.001) and treatment (P < 0.020). Although only retail day was significant (P < 0.001) across all color traits with both models in data 3, results showed underreported differences due to the inability of metric models to account for extreme skewness in post hoc comparisons.

Conclusion: Though subjective panel data appear numeric, the data are still ordered categories. Metric models fail to consider the latent scale implied in data that employs Likert-like scales such as panel ratings. Type I and II errors, and underreported differences under various circumstances by the metric models, were detected, pointing out that this method is unreliable when handling ordinal data. Ordinal models are the statistically appropriate choice for analyzing ordinal data such as sensory panels (both consumer and trained), beyond subjective meat color.

Keywords: beef subjective color, categorical data, ordinal data, statistical analysis, statistical models

134 UNDERSTANDING POTENTIAL ETIOPATHOGENESIS OF WOODY BREAST MYOPATHY IN BROILER CHICKENS

P. Maharjan^1,*, ¹Food and Animal Sciences, Tennessee State University, Nashville, Tennessee, United States *pmaharja@tnstate.edu

Objectives: The US poultry industry has seen various muscle myopathies in modern broiler strains along with the recent one called Woody Breast (WB) myopathy. The aim was to understand the potential causes of WB myopathy by analyzing biomarker differences between affected and normal birds at different stages of growth.

Materials and Methods: Multiple broiler floor pen feeding studies (n = 3) were performed utilizing two high yielding meat broiler lines (>48 pen studies). Metabolic tools were applied to assess biomarker differences in WB-affected birds and normal birds at various ages of bird grow out period.

Results: Our investigations revealed that, by day 42, these broiler lines were synthesizing mixed muscle protein in the Pectoralis major at a rate 8% higher compared to broilers raised 2 decades earlier under different nutritional guidelines. WB-affected birds showed higher expression of plasma 3-methylhistidine and increased mixed muscle degradation rates in the Pectoralis major (P < 0.05) Histomicrographs of WB-affected muscles displayed significant myodegeneration as early as day 21, with muscle-specific protein being replaced by collagenous tissue. The level of insoluble collagens increased as the birds aged. Metabolomic analysis identified differences (P < 0.05) in plasma metabolites between myopathy-affected and normal birds (served as control), suggesting circulatory insufficiency and potential cardiovascular involvement. Transcriptomics analysis revealed differential gene expression associated with hypoxia, oxidative stress, carbohydrate metabolism, muscle growth, calcium signaling, and cell membrane integrity, particularly at day 56. WB-affected birds exhibited lower protein-to-fat ratios and reduced maintenance heat production.

Conclusion: The WB myopathy resulted in the loss of both quality and quantity of muscle protein, warranting future research need focused towards improving vascularity in the Pectoralis in meat broiler lines.

Keywords: broilers, etiopathology, woody breast myopathy

135 DETERMINING MEAT YIELDS AND ECONOMIC VALUES OF BONER AND LEANER COWS

Z. T. Ortman^1,*, K. G. Scott¹, M. Conte¹, Y. Wang¹, B. M. Bohrer¹, L. G. Garcia¹, ¹Animal Sciences, The Ohio State University, Columbus, Ohio, United States *garcia.625@osu.edu

Objectives: The objective for this experiment was to determine the effect of cull cow body condition score on carcass cutting yields and processing profitability.

Materials and Methods: Twenty cull cows were purchased from a commercial sale barn in Ohio seeking to represent boner (n = 10) and leaner type (n = 10). Boner type cattle were chosen to represent average body condition scores (4, 5, 6) whereas leaner type cattle were selected to represent thin body conditions scores (1, 2, 3). Carcasses were fabricated 96 h postmortem where cold carcass weights were recorded followed by a cutting test of the left sides of each carcass. Cutting tests accounted for weights of boneless subprimals, bone, fat, and lean following the basic USDA cutter cull cutout and boxed beef cuts targeting 0.635 cm of fat trim. Market value (as of 23 June 2023) was applied using the USDA Carlot Report. Total value of merchandized meat subprimals, total value of merchandized boneless subprimals, trim and bone, and total value of merchandized trim and bone were calculated. Data were analyzed using a randomized complete block design with fixed effects of treatment (boner or leaner), a random effect of slaughter day, and with live weight serving as a covariate.

Results: Summary statistics revealed weight differences in hot carcass weights, subprimals, lean trim, fat, bone, and total weights. Percent total yields varied between the boner (98.14%) and leaner (96.57%) categories with leaner carcasses being lighter and more variable in percent yields. Boner type were 9.8 kg heavier than those of leaner type. In all instances, boner type yielded subprimals that were greater in weight, yet only a few of these were statistically different in this study [likely due to the small sample sizes (n = 10 cows/treatment) and variation between carcasses]. The inside round (P = 0.01), bottom round (P < 0.01), strip loin (P = 0.04), top sirloin (P = 0.04), and flank (P = 0.03) were all greater in boner type. Additionally, the leaner type had a greater amount of bone, both on a weight basis (P = 0.05) and percentage of the side weight (P = 0.01). With most subprimals of greater numerical value for boner type. Those that were statistically different (P ≤ 0.05) included the inside round (+$7.25/carcass) and the bottom round (+$10.98/carcass). On average, the purchase of boner ($1,242.39) and leaner ($1,098.25) cows were accounted for and compared to meat profitability. Overall, when cuts were summed together as the total value of merchandized cuts, the numeral difference (P = 0.09) between boner and leaner type was $47.04/carcass. Although none were statistically different (P ≥ 0.16), the numerical difference for value of lean trim was $43.96/carcass, fat trim was $8.68/carcass, and bone was −$6.98/carcass between boner cows and leaner cows, respectively. When only accounting for overall profit for total value of merchandized cuts, lean and fat trim, and bone values, overall profit in this study revealed an average profit of $66 for boner cows and $122 for leaner cows. However, when only considering meat profitability (total value of merchandized cuts and lean trim) boner cows resulted in a −$57 loss and leaner cows resulted in −$4.26 profit loss.

Conclusion: Boner type yielded greater valued carcasses considering yield and the total yield of merchandized cuts. It is important to consider that these cows are marketed differently by meat packers, as both subprimal cuts and trim are normally marketed for boner type, whereas trim is normally marketed for leaner cows creating potential difference in revenue. Differences between live prices between types can create situations where return on investment can seem favorable for leaner type, albeit constraints in the confirmation and quality of cuts may limit marketability of cuts from leaner cows when compared with boner type. This warrants future multi-disciplinary research efforts evaluating animal production, market dynamics, and meat science.

Funding Source: Ohio Food Bank Association, Ohio Beef Council, and United Producers Inc.

Keywords: beef, body condition scores, cull cows, meat yields, merchandizing values

136 THE EFFECT OF BODY CONDITION SCORE OF BEEF COWS ON CARCASS CHARACTERISTICS AND DEVELOPMENT OF TENDERNESS IN THE LONGISSIMUS LUMBORUM AND PSOAS MAJOR MUSCLES

K. G. Scott^1,*, Y. Wang¹, B. M. Bohrer¹, L. G. Garcia¹, ¹Animal Sciences, The Ohio State University, Columbus, Ohio, United States *garcia.625@osu.edu

Objectives: Beef cows in the United States have been culled at a record level in recent years; therefore, understanding the optimal level of condition for marketed beef cows is important for the industry. The objective for this study was to determine the effect of cull cow body condition score on carcass characteristics and the development of tenderness for the longissimus lumborum (LL) and psoas major (PM) muscles.

Materials and Methods: Ten boner cull cows (BCS 4–6) and ten leaner cull cows (BCS 1–3) were purchased at a commercial sale barn in 3 different groups, with each group having 3 or 4 cows of either the boner or the leaner category. Cows were native type that were predominantly black hided that also included a Charolais, Hereford, and Black Baldy. Carcass characteristics (ribeye area, backfat thickness, muscle score, fat color, marbling, skeletal and lean maturity, and carcass defects) were recorded after slaughter. The temperature and pH of the LL and PM muscles were monitored at 2, 4, 8, 24, 48, 72, and 96 h postmortem. Tenderness for the LL and PM muscles were measured following 4, 7, 14, 21, 28, 35, and 42 d of postmortem aging using Warner-Bratzler shear force. Carcass characteristics were analyzed using a randomized complete block design with fixed effects of treatment (boner or leaner), a random effect of slaughter day, and with live weight serving as a covariate. Temperature/pH decline as well as tenderness were analyzed with the same model but with the addition of repeated measures of time postmortem.

Results: Boner cows had body condition scores and live muscle scores of 1.21 units and 0.96 units greater (P < 0.01) when compared with leaner cows. In addition, the carcasses from boner cows were 20.1 kg heavier (P < 0.05) and dressed 3.94 percentage units greater (P < 0.05) than leaner cows. This resulted in boner cows having greater levels of backfat thickness (0.39 cm greater; P < 0.05), a larger ribeye area (9.17 cm² larger; P < 0.05), and a greater marbling score (131 degrees greater; P < 0.05) when compared with leaner cows. Temperature decline of boner cows for the LL were slower compared with leaner cows; however, no significant differences existed for the PM. pH of boner cows for the LL was less (P < 0.05) than the leaner cow group at 4, 8, 24, 48, and 72 h, yet there were no differences in PM (P > 0.05). Differences ranging from 0.5 to 1.0 kg (P < 0.15) were present between boner and leaner cows for Warner-Bratzler shear force values of the LL at 4, 28, 35, and 42 d postmortem, but there were only significant differences (P < 0.05) at 42 d postmortem where boner cows were 1.0 kg more tender than leaner cows [likely due to the small sample sizes (n = 10 cows/treatment) and variation of background between carcasses]. There were no differences (P > 0.15) in tenderness between boner and leaner cows for the PM.

Conclusion: Beef producers benefit from selling boner cows on a live weight or hot carcass weight basis as both weights were greater than leaner cows. Greater muscle scores, ribeye sizes, and marbling scores of boner cows indicate that these cows may be more beneficial to meat packers as well, by being more likely to be marketed for subprimal cuts versus only ground product. Minor differences were detected for temperature/pH decline and tenderness for the LL and PM muscles. Consumer evaluation of muscle size and sensory studies should accompany future research efforts on this topic.

Funding Source: Ohio Food Bank Association, Ohio Beef Council, and United Producers Inc.

Keywords: beef, body condition scores, carcass characteristics, cull cows

137 VARIATION IN MARBLING SCORE AND INTRAMUSCULAR FAT CONTENT AMONG VARIOUS RIBEYE AND STRIP LOIN STEAK LOCATIONS FROM BOTH SIDES OF BEEF CARCASSES

S. D. Shackelford^1,*, A. Everhart¹, K. Loomas¹, J. Stowater¹, K. Swinney¹, D. A. King¹, T. L. Wheeler¹, ¹USMARC, USDA-ARS, Clay Center, Nebraska, United States *steven.shackelford@usda.gov

Objectives: In the U.S., beef carcass quality grading is primarily a function of marbling score. The United States Standards for Grades of Carcass Beef (USDA, 2017) state that “when both sides of a carcass have been ribbed prior to presentation for grading and the characteristics of the two ribeyes (area, marbling, color, texture, and firmness) would justify different quality and/or yield grades, the final grade of the carcass shall reflect the ‘highest’ of each of these grades as determined from either side.” Marbling score can frequently differ among carcass sides. Additionally, visible marbling and intramuscular fat content can differ among the various ribeye and strip loin steaks from a carcass. Consequentially, beef industry leadership often face complaints from industry professionals and consumers that steaks do not appear to have the expected level of marbling for the quality grade program. Therefore, this project was conducted to determine the sources and level of variation in beef grading camera marbling score and intramuscular fat (IMF) among various ribeye and strip loin steak locations from both sides of Certified Angus Beef (CAB) and CAB Prime carcasses.

Materials and Methods: At a large-scale Midwestern beef packing plant, CAB (n = 30) and CAB Prime (n = 10) carcasses were selected after grading and certification. Using a VBG2000-GigE-7L grading camera, carcasses were selected to represent the expected distribution of “high side” marbling scores for CAB and CAB Prime as well as the expected distribution of difference between “high side” and “low side” marbling score for CAB. The 180 strip loin and 112A lip-on ribeye were obtained from both sides of each carcass, vacuum-packaged and transported to USMARC. Each subprimal was sliced into steaks. The posterior surface of each steak was bloomed (15 min) and imaged in triplicate with the grading camera. Ether-extractable IMF was determined on one-half of the steak locations (see figure).

Results: Steak location in strip loin and ribeye affected marbling score and IMF in CAB and CAB Prime (P < 0.05). The marbling score of the posterior surface of steaks, which were close to each other (approximately 163 mm apart) and near the 12^th to 13^th ribbing location, differed by 101 and 67 units for CAB and CAB Prime, respectively (P < 0.05). But IMF did not differ between these locations for either CAB or CAB Prime (P > 0.05). Marbling scores were <Modest for 27%, 30%, and 40% of CAB carcass sides, CAB strip steaks, and CAB ribeye steaks, respectively. In comparison to CAB carcass sides, a higher percentage of CAB ribeye steaks had marbling scores < Modest (P < 0.05). Marbling scores was < Slightly Abundant for 15%, 55%, and 51% of CAB Prime carcass sides, CAB Prime strip steaks, and CAB Prime ribeye steaks, respectively. In comparison to CAB Prime carcass sides, a higher percentage of CAB Prime ribeye steaks and CAB Prime strip steaks had marbling scores < Slightly abundant (P < 0.01).

Conclusion: This research shows that there is much random variation and some systematic variation in marbling score and ether-extractable IMF among longissimus steaks from the same quality grade program. This information will provide scientific basis for informed education of meat industry professionals and consumers on expected level of variation in visible marbling and chemical IMF.

Funding Source: USDA-ARS

Keywords: beef, fat, Intramuscular, marbling, variability

138 IMPACT OF NATIVE MICROBIOME COMMUNITY ON BEEF COLOR AND OXIDATIVE STABILITY

J. Rodriguez^1,*, P. Dias-Morse², B. Zuo², J. Zhao², K. R. Vierck², J. W. S. Yancey², D. Setyabrata^1,2, ¹Department of Animal Science, ²Department of Animal Science, University of Arkansas System Division of Agriculture, University of Arkansas, Fayetteville, Arkansas, United States *jr109@uark.edu

Objectives: Postmortem aging is a widely practiced post-harvest technique used to improve the palatability of beef products. While this process significantly improves beef palatability, extended aging has been shown to induce quality deterioration, such as lower oxidative stability and rapid discoloration. Additionally, a prolonged aging period could also lead to early product spoilage due to excessive microbial growth and activity. While numerous studies have profiled the microbial community changes in meat, information regarding its influence on aged meat quality attributes and their impact on color stability is still limited. The overall objective of this study was to profile the microbial community shift during the display period following aging and identify its impact on final beef color stability.

Materials and Methods: Five beef striploins from one side of the animal (M. longissimus lumborum, USDA low choice, A maturity, Angus cross) were collected at 3 d postmortem from two different processing plant facilities (P1 and P2). Upon arrival, muscles were aged to 7 d, cut into 5 equal sections and randomly assigned into 5 different wet-aging durations: 1) no additional aging (A7), 2) aged to 14 d (A14), 3) aged to 21 d (A21), 4) aged to 28 d (A28), 5) aged to 35 d (A35). Samples were individually vacuum packaged, placed into a box and aged at 2°C. At the designated aging period, the samples were cut into 2 steaks for pH, 7 d simulated color display, lipid oxidation, microbial quantification and microbiome profiling. The study was a randomized complete block design. Meat quality data was analyzed using SAS 9.4. Microbiome data was analyzed using Qiime 2.

Results: Final meat pH was found to be similar regardless of the processing plant (P > 0.05). Increased aging time decreased color quality and stability during display regardless of facility source (P < 0.05). Samples from P1, however, had a greater decrease and lower color quality compared to P2 throughout the display (P < 0.05). Similarly, lipid oxidation increased with a longer aging period (P < 0.05). After display, greater lipid oxidation increase was observed in samples from P1 compared to P2 (P < 0.05). Both aerobic and lactic acid bacteria concentrations were greater with longer aging (P < 0.05) and in higher P2 compared to P1 (P < 0.05). Microbiome analysis revealed that microbial community was similar prior to display (P > 0.05) regardless of facility. However, microbial community was different and clustered based on the facility source after display (P < 0.05). Further analysis exhibited that P2 had more variation of microbial groups compared to P1 potentially influencing the meat color and oxidative stability.

Conclusion: The results of this study indicate that prolonged aging practices negatively impact beef color and oxidative stability. Steak samples obtained from P2 displayed a greater overall color quality, although the samples had a greater microbial count than P1 samples. Microbiome analysis indicated that microbial diversity potentially influenced the final meat color and oxidative stability. Identification of the microbial community impact on volatile compound production is currently ongoing. Further studies to elucidate the mechanisms impacted by the microbial organisms and confirm their impact on meat quality development will be warranted.

Funding Source: This research is funded by the Arkansas Beef Council.

Keywords: beef, color stability, microbiome, oxidative stability, shelf-life

139 EFFECTS OF BLOOM TIME ON BEEF GRADING CAMERA MEASURES

J. C. Morrill^1,*, W. J. Horne², B. L. Gwartney², ¹Department of Animal Science, University of Nebraska-Lincoln, Lincoln, Nebraska, United States, ²Agricultural Marketing Service, United States Department of Agriculture, Washington D.C., United States *jessiecmorrill@gmail.com

Objectives: Beef grading cameras are often used to assign value to beef carcasses in the United States, in conjunction with professionally trained USDA graders. As building footprints, cooling capabilities, and processes differ among commercial packing plants, there are factors that may interfere with the accuracy of grading camera measurements between facilities. Therefore, there is a current need to understand how the length of time between carcass ribbing and presentation for grading, often referred to as “bloom time”, may impact grading camera measures. Our objectives were to understand temporal and visual changes in the ribeye during bloom and to determine how these changes impact outputs of 3 beef grading camera models.

Materials and Methods: Immediately following harvest, continuous data-logging thermometers were placed into beef carcass sides (n = 32) through the intercostal meat between the 6^th and 7^th ribs, so that the probe was inserted into the approximate geometric center of the longissimus dorsi muscle. At 18 to 22 h post-harvest, carcasses were ribbed and immediately assessed unbloomed (0BL) and after 30 min and 120 min of bloom time (30BL and 120BL, respectively). At each timepoint, the internal rib temperature was recorded, ribeye surface temperature was measured using an infrared thermometer, objective color (L*, a*, b*) was characterized, and the ribeye was imaged with E+V GigE, E+V Handheld, and Meat Image Japan (MIJ) grading cameras. At the end of the experiment ribeye traits were characterized using a ribeye dot grid, USDA Marbling Cards, and a USDA PYG ruler. Data were analyzed using R (version 4.0) and R Studio (tidyverse version 1.3.0, nlme, version 3.0). Time was considered significant at P ≤ 0.05. When time was significant, pairwise comparisons were made using paired t-tests and were considered significant at P ≤ 0.05.

Results: Marbling measurements obtained from the E+V GigE, E+V Handheld, MIJ grading cameras declined between 0BL, 30BL, and 120BL (P ≤ 0.01). The decline in marbling measurements may be partially explained by increases in a* and b* color values with increased bloom time (P < 0.001); L* values were not significantly different (P = 0.17). Marbling score differences may have also been partially impacted by reductions in internal rib temperature that occurred between 0BL, 30BL, and 120BL (P < 0.001). Ribeye surface temperature was highly sensitive to changes in the ambient temperature and airflow and was not significantly different between 0BL, 30BL, and 120BL (P = 0.20).

Conclusion: These data indicate that increasing bloom time for up to two h post-ribbing reduces marbling score outputs by beef grading cameras and that consideration should be given to the placement of camera grading equipment in relation to areas where beef carcasses are ribbed. Consideration should also be given to the length of time carcasses may need to be held for regrading. Additionally, chilling time may affect visual properties of lean and/or intramuscular fat and, thus, grading camera outputs. Additional research should be conducted to determine when camera grading measurements are most reflective of chemically verifiable intramuscular fat content, and are thus, most indicative of beef eating quality.

Funding Source: This research was funded by the USDA Agricultural Marketing Service.

Keywords: beef, bloom, camera grading, marbling, quality

140 ASSOCIATION BETWEEN BEEF RIBEYE AREA MEASUREMENTS AND STEAK PORTION SIZE

A. F. Schiefelbein^1,*, C. L. Smith¹, J. A. Scanga¹, K. E. Belk¹, R. J. Delmore¹, D. L. Clark², M. N. Nair¹, ¹Department of Animal Sciences, Colorado State University, Fort Collins, Colorado, ²Meat Science, Certified Angus Beef, Wooster, Ohio, United States *abbey.schiefelbein@colostate.edu

Objectives: As cattle weights have increased over the past decades, hot carcass weight and ribeye area (REA) have also increased. Ribeye area is an important determinant of carcass value as it impacts the thickness of steaks when portioned to a pre-determined net-weight. Additionally, previous research has indicated that steak thickness impacts consumers’ eating experience. The objective of this study was to examine the relationship between carcass REA and steak portion sizes.

Materials and Methods: Beef carcasses (n = 100) were selected from a commercial beef harvesting facility based on REA in 1 in² (6.45 cm²) increments ranging from less than 11 in² (70.97 cm²) to greater than 19 in² (122.58 cm²) based on a USDA-approved camera (E+V) with 10 total categories. Data (hot carcass weight, back fat thickness, and marbling) were collected from each selected carcass. The REA measurements were obtained using the grading camera, a manual grid, and pen tracing and measured using ImageJ software. Striploins (IMPS#180) from selected carcasses were collected, and weight, length, and 3 width (anterior, middle, and posterior) measurements of the striploins were measured manually. Each striploin was then scanned through Marel I-Cut 56 portion cutter to determine the thickness of 12 oz (340.19 g) and 16 oz (453.59 g) portions and to determine the weight of a 1-in (2.54 cm) thick portion. To quantify and describe the relationship between steak thickness (cut to 12 oz and 16 oz portions) and steak weight (cut at 1-inch thickness), linear regression models were developed using camera REA and traced REA as independent variables. Additionally, more exhaustive linear regression models were developed to predict steak thickness or weight based on the camera REA, hot carcass weight, fat thickness, striploin weight, striploin length, striploin width, and average maximum height of the striploin. Each model was evaluated \separately for the main effects of each variable, with significance determined at α = 0.05.

Results: There was a significant (P < 0.001) correlation and linear relationship (P < 0.05) between camera REA measurement and 12 oz (R² = 0.62), 16 oz (R² = 0.62), and 1-inch-thick (R² = 0.65) portions examined in this study. For 12 oz steaks, the steak thickness decreased by an estimated 0.043 inches (0.11 cm) for every 1-inch increase in REA. Similarly, for the 16 oz steaks, the steak thickness decreased by an estimated 0.059 inches (0.15 cm) for every square inch increase in REA. The 1-inch steak portions had a mean weight of 340 g, and the steak weight increased an estimated 10 g for each square inch increase in REA. In addition, using the striploin measurements, linear regression models were able to predict steak thickness for 12 oz and 16 oz portions with an R² of 0.95 each, and predict the steak weight for the 1-inch portion with an R² of 0.98.

Conclusion: As expected, REA had a strong relationship with the portion size of striploin steaks cut to a specified weight or thickness. Additionally, our results indicated that the weight and length of the striploin were good predictors of steak thickness (for 12 oz and 16 oz portions) or steak weight (for 1-inch-thick portions). Further research exploring consumer acceptance and degree of doneness for steaks with varying thicknesses would provide data to determine REA ranges and targets that would optimize steak portion sizes and consumer acceptability.

Funding Source: Certified Angus Beef.

Keywords: beef, ribeye area, steak thickness

141 EFFECT OF BREED TYPE ON GOAT CARCASS TRAITS

L. A. Kinman^1,*, W. Foxworth¹, M. M. Franklin¹, S. Horner¹, I. Gilmore¹, J. I. Evans¹, ¹Department of Agriculture, Nutrition, and Human Ecology, Prairie View A&M University, Prairie View, Texas, United States *lakinman@pvamu.edu

Objectives: Due to the rise in ethnic diversity, there has been an increase in the demand for goat meat in Texas and the greater United States. While the Spanish breed is the most common meat-type goat in the U.S., the Boer breed, which was developed in South Africa specifically for meat production, is gaining popularity due to its large frame size and muscularity. Although the Boer breed should produce more saleable product than Spanish goats, they are not as productive when forage conditions are suboptimal. An extensive study is currently being conducted to develop a composite goat breed that combines the resilience, hardiness, and maternal capabilities of the Spanish goat with the muscular development of the Boer goat. The objective of this preliminary carcass analysis is to assess the influence of breed-type on carcass traits of meat-type goats during the initial phases of composite development.

Materials and Methods: Breed types included in this study were purebred Boer (n = 9), purebred Spanish (n = 25), F1-BS cross (Boer female × Spanish male; n = 10), F1-SB cross (Spanish female × Boer male; n = 24), F2-BSS (F1-BS × Spanish male; n = 5), and F2-SBB (F1-SB × Boer male; n = 3) goat kids sourced from the International Goat Research Center at Prairie View A&M University. Goat kids were slaughtered at the Prairie View A&M University Meat Science Center at an average age of 200 d. Immediately following slaughter, hot carcass weight and initial muscle pH were collected. Carcasses were then chilled at 0°C and at 24 h postmortem, 24-h pH, length of carcass (measured from the point of the hock to the point of the shoulder) and leg circumference (across the stifle area of the leg, measuring each individual leg and combing individual measurements) were collected. At approximately 72 h postmortem, goat carcasses were processed, loin eye area measured at 12^th rib, and body wall thickness (5.1 cm from the ventral edge of the longissimus dorsi) data were collected. A subsample from each breed-type: Boer (n = 6), Spanish (n = 8), F1-BS cross (n = 5), F1-SB cross (n = 9), F2-BSS (n = 3), and F2-SBB (n = 2) was dissected to collect weight of bone, fat, and muscle to determine the physical composition. Data were analyzed as a completely randomized design using the GLIMMIX model in SAS v. 9.4 (SAS Institute, Cary, NC, USA). Statistical significance was set at P ≤ 0.05.

Results: There were no differences found (P > 0.05) between breed type on initial pH, 24-h pH, hot carcass weight, leg circumference, loin eye area, body wall thickness, and weight of fat, muscle, or bone for physical composition. There was a difference found (P < 0.05) in carcass length, as F1-SB had a longer carcass (109.34 cm) compared to F2-BSS (91.91 cm).

Conclusion: In summary, the preliminary data suggest that there were no notable differences between breed types concerning carcass traits, with the exception of carcass length, during the initial stages of composite development. As the composite breeding progresses, further analysis with larger sample sizes with be conducted to enhance the statistical power of the data.

Funding Source: USDA-NIFA-Evans Allen grant.

Keywords: breed type, carcass traits, goat, pH

142 TO ASSESS THE BEEF MUSCLE-SPECIFIC EFFECTS OF PHOTOOXIDATION ON MEAT COLOR STABILITY

R. Kumar^1,*, K. Harr¹, G. Mafi¹, M. Pfeiffer¹, S. P. Suman², R. Ramanathan¹, ¹Animal and Food Sciences, Oklahoma State University, Stillwater, Oklahoma, United States, ²Animal and Food Sciences, University of Kentucky, Lexington, United States *rishav.kumar@okstate.edu

Objectives: In the US, case-ready beef is sold primarily in retail cases under display light conditions. Various studies have shown that light increases meat discoloration compared with dark storage. However, limited studies have determined the biochemical basis for faster discoloration under retail light conditions. Hypothesis: We hypothesize that light-induced oxidation will decrease oxygen consumption and metmyoglobin reducing activity and will decrease color stability. Therefore, the objective was to determine the impact of light and dark display conditions on the retail color, lipid oxidation, oxygen consumption, and metmyoglobin reducing activity of longissimus lumborum (color stable) and psoas major (color labile) muscle.

Materials and Methods: USDA Low-choice short loins (n = 8) were collected from a commercial processing plant 14 d postmortem. The psoas major muscle was separated from the longissimus lumborum and each muscle was sliced from the anterior end. Steaks were evaluated for color, pH, bloom, lipid oxidation, oxygen consumption, and metmyoglobin reducing activity. Steaks utilized for light display (1000 lux) and dark storage were individually placed onto Styrofoam® trays, overwrapped with polyvinyl chloride film, and placed into simulated light or dark storage for 5 d for psoas major and 10 d for longissimus lumborum. Color measurements were taken 1, 3, 5, 8, and 10 d during light and dark storage. Lipid oxidation, oxygen consumption, and metmyoglobin reducing activity were analyzed on d 0, 5, and 10. Oxygen consumption and metmyoglobin reducing activity were determined on the surface exposed to oxygen/air (exterior) and interior (non-oxygen contact surface), whereas lipid oxidation was measured on surface exposed to oxygen/air (exterior) only. All color measurements were taken using a HunterLab MiniScan spectrophotometer. The experiment design was a split-plot design (n = 8 replications). All data were analyzed using the Glimmix procedure of SAS with significance at a P < 0.05.

Results: As expected, longissimus and psoas steaks in light discolored more (P < 0.05) than dark storage (psoas > longissimus; P < 0.05). On days 5 and 10, psoas and longissimus steaks in light had greater pH (P < 0.05) than dark storage, respectively. Lipid oxidation was greater (P < 0.05) in both longissimus and psoas steaks kept in light and dark storage (psoas > longissimus; P < 0.05). In addition, oxygen consumption and metmyoglobin reducing activity were greater in steaks kept in dark than displayed in light storage. In support, interior steaks stored in the dark had greater (P < 0.05) metmyoglobin reducing activity and bloom compared with light storage.

Conclusion: The results indicate that light increased lipid oxidation and decreased oxygen consumption and metmyoglobin reducing activity. Light had more detrimental effects on psoas than longissimus. These findings suggest that developing novel light systems or modifications in packaging film has the potential to minimize the impact of light-induced oxidative changes and extend the surface color of beef muscles.

Funding Source: We extend heartfelt thanks to the United States Department of Agriculture (USDA) for funding support toward this research project.

Keywords: color stability, longissimus lumborum, photooxidation, psoas major, retail color

143 EVALUATION OF MAGNETIC RESONANCE IMAGING (MRI) AND COMPUTED TOMOGRAPHY (CT) AS AN OBJECTIVE MEASURE OF CARCASS COMPONENTS AND INDICATOR OF RED MEAT YIELD

A. J. Main^1,*, T. M. Horton¹, H. Parmar², B. A. Foraker³, D. R. Woerner¹, ¹Animal and Food Sciences, ²Department of Electrical & Computer Engineering, Texas Tech University, Lubbock, Texas, United States, ³Animal Sciences, Washington State University, Pullman, Washington, United States *ammain@ttu.edu

Objectives: The beef industry has a considerable need for an improved measure of saleable red meatyield (RMY) for beef carcasses. Currently, the USDA yield grade does not accurately indicate true value differences in cattle. Utilizing magnetic resonance imaging (MRI) and computed tomography (CT) as a gold standard for measuring total beef composition could add accuracy and precision while reducing the labor required to determine the saleable yield of meat animals. Therefore, the purpose of this study was to demonstrate the capacity of the data produced by MRI and CT technologies for determining carcass composition on a component basis (muscle, fat, and bone) by performing a carcass dissection and carcass yield test, coupled with compositional measurements of lean, fat, and bone.

Materials and Methods: Carcasses (n = 3) were portioned into hindquarter, chuck/rib, and brisket/plate pieces to accommodate the bore size of the technologies and imaged. The carcass sides were then fabricated into a boneless, industry-standard cutout. Muscle, fat, and bone were calculated from measured weights and adjusted by chemical fat, which was analyzed on a whole carcass basis. MRI and CT images were processed and segregated into muscle, fat, and bone, and then the proportion of each was calculated.

Results: MRI was found to be an unsuitable option due to size restrictions and limitations in image post-processing. However, CT had an average difference of −3.8, −8.8, and 12.2% on measuring muscle, fat, and bone, respectively, when measured weight proportions were compared to CT volume proportions. This means CT underestimated muscle and fat while overestimating bone. The average difference decreased when CT volumes were corrected with reference densities for each respective tissue (muscle = 1.1, fat = 0.9, and bone = 2.2) to −1.5% in muscle, −3.5% in fat, and 4.6% in bone. Estimation errors occurred in the same direction. However, when CT volume proportions were regressed on measured weights and new CT values were calculated from the equations, the average difference between measured weights and calculated CT values for muscle, fat, and bone were −1.2%, 0.0%, and 0.03%, respectively. Thus, CT demonstrated its viability as a tool to measure total beef carcass composition and should be further pursued and refined.

Conclusion: MRI, while excellent for segregating soft tissues, is not well suited to be pursued for total beef carcass composition due both to its logistic and bone perception disadvantages. Contrarily, CT should be further pursued for total beef carcass composition. Work should continue in measuring more carcasses to better understand if density should serve as a coefficient, a regression equation can be calculated to increase accuracy, image processing can become more automated and more granular, or any combination of these.

Funding Source: This project was funded in part by the Beef Checkoff.

Keywords: beef, carcass composition, computed tomography, magnetic resonance imaging, red meat yield

144 EVALUATING THE USE OF iDXA X-RAY TECHNOLOGY TO PREDICT COMPOSITION OF PRIMALS IN BEEF CATTLE

K. R. Swinney^1,*, A. Mendizabal¹, B. A. Foraker², J. F. Legako¹, J. C. Brooks¹, M. F. Miller¹, D. R. Woerner¹, ¹Department of Animal and Food Sciences, Texas Tech University, Lubbock, Texas, United States, ²Department of Animal Science, Washington State University, Pullman, Washington, United States *kylan.swinney@ttu.edu

Objectives: Cattle composition has changed since the implementation of the USDA Yield Grade equation, and recent studies have noted a disparity between yield grade and ultimate red meat yield. Therefore, alternative technology is needed and should be consistent, objective, and accurate. Thus, the objective of this study was to evaluate the use of dual-energy X-ray absorptiometry (DXA) system technology to predict the composition of beef primals and, ultimately, red meat yield.

Materials and Methods: Cattle consisting of steers, heifers, and bulls were harvested in the meat laboratory at Texas Tech University. Following harvest, one side from each carcass (N = 41) were chilled for 6 d and then separated into the 4 primals (round, loin, rib, and chuck). After separation, each primal was scanned using iDXA technology under the setting for small animals. Each scan took 24 linear measurements, which were used to predict primal composition. Once scans were completed, primals were fabricated into wholesale cuts and untrimmed subprimals. The wholesale cuts and untrimmed subprimals were further deconstructed into 4 components: subprimal, lean trimmings (trim), fat trimmings (fat), and bone, and weighed; a weigh back was calculated and only sides with at least 98% weigh back were utilized. Composition of each subprimal was calculated from the measured component weights, where trim sources were adjusted to 90% lean and 10% fat, then the red meat yield and adjusted fat of a given primal was calculated accordingly. Linear measurements from iDXA were tested for multicollinearity, and those variables found with evidence of such were removed. An “all possible combinations” multiple linear regression approach was used to render several different models for each with composition variable with differing numbers of measurements included to select the model with maximized predictive power. The rendered models utilized data from the 41 carcasses selected for the study.

Results: Predictive models for adjusted fat of primals, using varying numbers of iDXA scan measurements, were found to be most effective across all primals. Most notably, in the loin, the R² value showed 87% of the variability in adjusted fat was accounted for by the model, and in the rib, 80% of the variability in adjusted fat was accounted for by the model. However, the accuracy in predicting red meat yield (subprimals plus 90% lean trimmings) and bone composition varied across the 4 primal cuts. Red meat yield of loin (R² = 0.83) was predicted more accurately than those of the rib, round, and chuck (R² = 0.52, 0.50, and 0.34, respectively) primal cuts. Model prediction for bone percentage followed a similar trend; the rib was predicted with the greatest accuracy (R² = 0.64), followed by the loin (R² = 0.52), round (R² = 0.45) and chuck (R² = 0.28).

Conclusion: Based on this study, iDXA technology has the potential to be an accurate predictor of fat in primals. However, data showed decreased ability of iDXA to account for variation in red meat yield and bone composition of the primal cuts. With this in mind, iDXA technology may not be the most viable option for predicting the composition of beef primals. However, more work should be done to determine whether the error lies in the technology or the cutout values against which it was measured.

Funding Source: This project was funded in part by the Beef Checkoff.

Keywords: beef, composition, AUTHOR: Please expand if appropriate.iDXA, x-ray, yield

145 INSTRUMENTAL ASSESSMENT OF MARBLING AND OBJECTIVE COLOR POST-RIBBING

W. W. Boyd^1,*, M. E. Eckhardt¹, W. J. Horne², B. L. Gwartney², T. E. Lawrence¹, T. E. Schwartz¹, L. W. Lucherk¹, ¹Department of Agriculture, West Texas A&M University, Canyon, Texas, United States, ²Agriculture Marketing Service, United States Department of Agriculture, Washington DC, United States *wboyd@wtamu.edu

Objectives: In the United States, USDA beef quality grades are assigned via USDA graders, with and without image analysis technology. Marbling scores (MS) are assessed at the anterior surface of the longissimus dorsi between the 12^th and 13^th ribs after exposure to air. The time between ribbing a carcass and when the grader or image analysis system views the ribeye is referred to as “bloom time.” Our objective was to evaluate the influence of temperature and bloom time on image analysis marbling and objective muscle color outcomes.

Materials and Methods: Beef ribs (USDA IMPS #103; n = 24) representing 4 quality levels (USDA Prime, Premium Choice [High and Average Choice], USDA Choice, and USDA Select) were sourced from Caviness Beef Packers and transported to the West Texas A&M University meat laboratory. Ribs were assigned to one of 3 temperatures [−2.2°C (28°F), 3.3°C (38°F), 8.9°C (48°F)] using a completely randomized design, with equal representation of quality levels (grade) among temperature (2 ribs/quality level/temperature). Rooms were set to the respective temperatures and ribs were allowed 48 h to equilibrate. Ambient temperature of each room was monitored and recorded throughout the study. One-cm-thick slices were cut from the posterior end of each rib to simulate the ribbing and blooming process 4 sequential times. Rib surfaces simulated for ribbing (n = 96) were evaluated for objective color values (L*, a*, b*) and image analysis marbling via 4 independent devices [E+V VBG 2000 (U.S. camera), E+V VBG Smart (portable camera), MEQ Camera (Australian camera), and MIJ Camera (Meat Image Japan camera)]. Camera images, objective color, surface temperature, and core temperature were collected across time after simulated ribbing (30 s, 2 min, 4 min, 6 min, 8 min, 10 min, 14 min, 18 min, 22 min, 26 min, 30 min, 38 min, 46 min, 1 h, 2 h, 4 h, 8 h). After 1 h, each cut surface was covered with oxygen transmissible polyvinyl chloride (PVC) perforated film to represent “re-grades”. Data were analyzed via mixed models as repeated measures.

Results: No time × grade interaction (P ≥ 0.15) was detected at any temperature for L*, a*, b* values. The L* values were higher (P < 0.01) for Prime ribs than other grades. An inconsistent relationship was recorded among a* values; Select ribs were reddest (P < 0.01) at −2.2°C, whereas Prime and Choice were reddest (P < 0.01) at 8.9°C. Both a* and b* increased (P < 0.01) as time passed during the first hour after simulated ribbing. Marbling results demonstrated a camera × grade interaction (P < 0.01); instrumental camera grading differed (P < 0.05) at varying levels across quality grades at every temperature. Notably the E+V VBG 2000 marbling scores were the highest (P < 0.01) for Prime ribs, whereas the MIJ system recorded the lowest (P < 0.01) MS at Prime and Premium Choice grades, and the highest (P < 0.01) MS at Select grades. All camera systems detected diminishing (P < 0.01) marbling scores during bloom; on average, MS decreased 1 degree every 2 min until PVC film was applied. After application of PVC film, MS increased by 1 degree every 28 min.

Conclusion: Results indicate instrumental marbling scores are maximized at every grade immediately after ribbing, and the utilization of PVC film can be a helpful tool for improving MS for re-graded carcasses. These results have potentially large economic implications for the beef industry.

Funding Source: Funded by the USDA.

Keywords: colorimeter, image analysis, instrument, myoglobin, smart phone

146 EVALUATION OF THE CORRELATION OF RED MEAT YIELD TO CARCASS MEASUREMENTS AND CUTOUT DATA IN ANGUS CATTLE

A. Carlock^1,*, M. Miller¹, D. Woerner¹, S. Shackelford², ¹Department of Animal and Food Science, Texas Tech University, Lubbock, Texas, United States, ²US Meat Animal Research Center, USDA-ARS, Clay Center, Nebraska, United States *anna.carlock@ttu.edu

Objectives: Since 1965, the USDA beef yield grading equation has remained the same. This original equation was compiled to estimate the percentage of closely trimmed rib, loin, chuck, and round providing the basis of the USDA yield grade equation. The current yield grade equation uses hot carcass weight (HCW), 12^th rib fat thickness, longissimus muscle area, and kidney, pelvic, and heart fat percentage (KPH). However, this estimate was developed using a small population of cattle that no longer exists to predict red meat yield (RMY) of cuts from carcasses that are increasingly more variable in management and genetic type. Studies have reported other variables could be generated to improve the predictability of RMY. Additionally, our current grading technology can redefine appropriate linear measures to predict RMY and to re-parameterize USDA yield grades to appropriately fit the current cattle population. Therefore, the objective of this project is to evaluate the correlation of beef RMY to carcass measurements and cutout data in Angus cattle.

Materials and Methods: One hundred and twenty-five head of fed Angus cattle (H = 54; S = 69; Freemartin = 1) were transported from the USDA Meat Animal Research Center to Nebraska Beef in Omaha, NE. After harvest, carcasses were allowed to chill for 24 h. Twenty-three measurements were taken on each carcass based on a set of preselected measurement points using a fabric 60-in cm metric tape measure (Table 1). Next, carcasses were split and allowed to bloom for 20 min ± 5 min. Ribeye area (REA), preliminary yield grade (PYG), and quality grade were measured on each carcass. Final yield grade (FYG) was calculated for each carcass using PYG, REA, HCW, and KPH. Carcass sides were separated at standard carcass breaks for the facility into wholesale cuts. Wholesale cuts were marked and followed throughout the production line and removed at their appropriate fabrication location where trained personnel fabricated wholesale cuts into subprimals, trim, fat, and bone. All pieces of each wholesale portion were weighed to an accuracy of 99% to 101% of the side HCW to obtain RMY.

All data were analyzed using R statistical software. Pearson correlations were calculated using the cor.test () function to evaluate relationships. Linear regression were calculated using lm() function, and P value and r² were recorded. Relationship was considered significant at P < 0.05.

Results: Data indicated a positive correlation amongst RMY and side HCW (P = 0.007; r = 0.24). There was correlation of RMY and measurements 2, 4, 6, 15, 20, 21, and 22 (r = 0.23, 0.25, 0.22, 0.30, 0.31, 0.26, and 0.30 respectively). Additionally, there was a strong positive correlation of RMY and FYG (P < 0.001; r = 0.55). RMY and REA were significantly correlated (P < 0.001; r = 0.34). There was a significant positive correlation amongst side HCW and REA (P < 0.001; r = 0.40).

Conclusion: The current yield grading equation only uses PYG, REA, HCW, and KPH to determine the FYG and RMT for each carcass. However, this study has demonstrated other factors including various carcass measurements have the ability to predict RMY in angus cattle. Research is still needed to redefine RMY in today’s cattle.

Keywords: grading technology, measurement, predictability, red meat yield, yield

147 INFLUENCE OF SODIUM ALGINATE COMBINED WITH NACL ON THE QUALITY ATTRIBUTES OF COOKED CHICKEN FILETS

J.-H. Liu^1,*, Y.-S. Chang², ¹College of Natural and Applied Science, University of Guam, Mangilao, United States Minor Outlying Islands, ²Animal Science, Chinese Culture University, Taipei, Taiwan, Republic of China *liuj14031@triton.uog.edu

Objectives: The ready-to-eat chicken filet is considered a worldwide popular dish, and it is essential to recognize how water retention capacity plays an effect on yields and sensory appeal (Droval et al., 2012). Recent research has delved into the influence of polysaccharides on protein properties, including studies by Yao et al. (2018) and Chen et al. (2014), which examined the effect of sodium alginate on the characteristics of myosin gels and actomyosin gel strength. Sodium alginate, valued for its thickening properties, contributes to enhanced gelling characteristics in the production of restructured and meat products (Thangavelu et al., 2019). This study aims to investigate the impact of combining sodium alginate with NaCl on the quality attributes of cooked chicken filets, enhancing our understanding of their potential to improve the overall quality of poultry products.

Materials and Methods: Refrigerated 1 d postmortem broiler breasts (Pectoralis major, N = 60) were sourced from a local meat processor. Chicken breasts were cubed into 3 × 3 × 6 cm filets and assigned different treatments: marinated in equal weight of NL (1% NaCl), SA (0.5% Sodium Alginate), NLSA (0.5% Sodium Alginate and 1% NaCl) solution, or directly vacuum-packaged (CON, N = 15) for 24 h at 40°F. Subsequently, samples were transferred to polypropylene bags and heated in 185°F water bath until reaching internal temperature of 160°F. then cooled for 30 min in running tap water. Objective color features and cooking yield were assessed. Color features (CIE-L*, a*, and b*) were measured using a colorimeter (3nh Technology Co., Ltd., China) equipped with an 8 mm aperture using illuminant D65 setting. Shear force was assessed the second day (40°F overnight). Statistical analysis was performed using SAS (v. 9.3; SAS Institute, Inc., Cary, NC) employing mixed model procedures, with significance set at P values lower than 0.05.

Results: No significant differences were observed in cooked color features among all groups (P > 0.05). The shear force was significantly lower in NLSA and SA treatments compared to NL and CON (P < 0.05). Additionally, the cooking yield was significantly higher in the NLSA treatment compared to SA, NL, and NLSA (P < 0.05), no significant difference was observed between NL and NLSA (P > 0.05). Our results suggest that the combination of sodium alginate with NaCl resulted in higher cooking yield and lower shear force compared to sodium alginate or sodium chloride alone (P < 0.05), without negatively impacting the cooked meat color of chicken filets.

Conclusion: While color properties of cooked chicken filets remained unaffected by the marination with 0.5% sodium alginate, 1% sodium chloride, or their combination, the combination of sodium alginate and sodium chloride significantly improved both the shear force and cooking yield of the chicken filets.

Keywords: Chicken filet, cooking yield, Meat Quality, Sodium Alginate

148 RELATIONSHIP OF USDA YIELD GRADE TO FATTY ACID COMPOSITION OF BACKFAT IN FEEDLOT-FINISHED LAMB

J. Yang^1,*, L. A. Pettey¹, T. Hackmann¹, P. Vahmani¹, ¹Animal Science, University of California, Davis, Davis, California, United States *emryang@ucdavis.edu

Objectives: Previous studies have focused on relationships between diet composition and the fatty acid composition of lamb fat. However, limited research has been carried out to explore the effects of yield grade (YG) on lamb fatty acid composition. Therefore, the objective of this study was to determine the fatty acid composition of backfat across YG classes (1, 2, 3, 4, 5) in feedlot-finished lambs.

Materials and Methods: A total of 232 lambs from Superior Farms (Dixon, CA) were used in the present investigation. The lambs shared the same paternal lineage of a black-faced Suffolk sire and a maternal side of either a white-faced Rambouillet or Western ewe. Lambs were on the same pasture-based diet for 8 mo after birth and then moved to a commercial feedlot, where they were finished on a grain-based diet for 2.5 mo. The lambs were processed at Superior Farms plant, graded with a USDA-approved VSS2000 camera grading system (e+v, Oranienburg, Germany) and classified into YG 1–5. Backfat samples were selected from 20 random carcasses within each YG category after initial sampling. Backfat subsamples (40 mg) were freeze-dried and direct-methylated, using sodium methoxide followed by GLC analysis of the resulting fatty acid methyl esters. Data were analyzed by ANOVA using the general linear model procedure of R. The statistical model included the fixed effect of YG. Differences were considered significant at P < 0.05, and in that case were followed by a Tukey multiple comparison test.

Results: Yield grade distribution of the carcasses (n = 232) was 0% YG1, 12% YG2, 47% YG3, 28% YG4, and 13% YG5. Carcass weight means were increased (P < 0.05) with the increase in yield grades (85 lb, 94 lb, 106 lb, and 114 lb for YG2, YG3, YG4, and YG5 respectively). Yield grade significantly affected the backfat content of several individual fatty acids, saturated fatty acids (SFA), but not monounsaturated fatty acids (MUFA) or polyunsaturated fatty acids (PUFA). YG5 had the highest content of SFA at 49.4%, which was significantly (P < 0.01) higher than the SFA content in YG2 (45.4%) and YG3 (46.4%). YG4 had the second highest SFA content (48.3%), which was significantly (P < 0.05) higher than the SFA content in YG2 but was not different (P >0.05) from that in YG3 or YG5. These differences were mainly a consequence of increased backfat content of de novo synthesized SFA, including C12:0, C14:0, and C16:0 with the increase of YG from 2 to 5.

Conclusion: Our findings suggest that the fatty acid profiles are not uniform across the USDA YG in feedlot-finished lambs. As the YG increases, the percent of atherogenic fatty acids, namely C12:0, C14:0 and C16:0, in lamb fat increases, which could negatively impact its overall healthfulness and nutritional value.

Funding Source: There was no direct funding provided for this project; however, the authors would like to acknowledge the support of Superior Farms Inc.

Keywords: fat quality, lamb, saturated fatty acid, yield grade

149 EVALUATING THE CORRELATION OF CLOSELY TRIMMED RETAIL CUTS TO RIBEYE AREA, 12TH RIB BACKFAT, BODY WALL, AND HOT CARCASS WEIGHT USING CUTOUT DATA IN LAMB CARCASSES

J. Bagby^1,*, M. F. Miller¹, D. R. Woerner¹, S. P. Jackson¹, ¹Animal and Food Sciences, Texas Tech University, Lubbock, Texas, United States *jacob.bagby@ttu.edu

Objectives: Lamb carcass evaluation has been guided by predictive equations that have been utilized for over 30 years. As the industry moves forward, it is imperative to investigate the accuracy of the predictions. This study aimed to evaluate the correlation between ribeye area, 12^th rib backfat, body wall and hot carcass weight to closely trimmed retail cut percentages found through cutout data of lamb carcasses.

Materials and Methods: A total of 62 lamb carcasses from the Gordon W. Davis Meat Laboratory were harvested and data was collected on the left side of the carcasses for ribeye area, 12^th rib backfat, body wall thickness, yield grade, as well as the hot carcass weight. Carcasses were then split and separated into primal wholesale cuts, fat, lean trim, tissue, and bone. Cutout data was collected on the left side of the carcass to determine the percentage of closely trimmed retail cuts or red meat yield. Data collected from the cutout was correlated to the measurements using R Statistical Software. Pearson correlations were ran using the cor.test() function and linear regressions were ran using the lm(). Statistical significance was found using P < 0.05, and P value was recorded.

Results: The analyzed data indicated a strong positive correlation between ribeye area and percentage of closely trimmed retail cuts and also was statistically significant (r = 0.74; P < 0.001). The relationship between backfat and percentage of closely trimmed retail cuts indicated a negative or inverse correlation and was statistically significant (r = −0.52, P < 0.001). Body wall measurement and percentage of closely trimmed retail cuts showed a negative correlation and did not have a statistically significant relationship (r = −0.18; P = 0.1615). Lastly, results indicated a positively correlated relationship between hot carcass weight and percentage of closely trimmed retail cuts and had a statistically significant relationship (r = 0.53; P < 0.001).

Conclusion: The data revealed that factors such as ribeye area, backfat, and hot carcass weight of lamb carcasses are crucial to percentage of closely trimmed retail cuts and are good indicators of red meat yield. Whereas body wall thickness may be a factor that is not as crucial into the final percentage of closely trimmed retail cuts. All 4 of these measurements (ribeye area, backfat, body wall, and hot carcass weight) are currently accounted in the equation predicting percentage of boneless closely trimmed retail cuts, and the current yield grade equation only accounts for backfat measurement. The correlations in this study indicated after decades utilizing the same equations for boneless closely trimmed retail cuts and yield, it could be time to re-evaluate the significance of each measurable factor toward the predictions of both equations. Further studies should be conducted to observe and re-evaluate the current equations made for predicting both percentage of boneless closely trimmed retail cuts as well as yield grading in lamb carcasses. New technology, such as 3D imaging, could play a large role into new research in this field which could change the industry in a huge way.

Funding Source: Dr. Mark Miller, Texas Tech University.

Keywords: closely trimmed retail cuts, cutout, lamb, prediction, yield

150 ADVANCEMENTS IN GENETIC EVALUATION OF FAT QUALITY IN PIGS USING NEAR-INFRARED SPECTROSCOPY

M. Schulte^1,*, C. Mitchell¹, E. Gjerlaug Enger², ¹Global Technical Services, Topigs Norsvin, Den Bosch, Netherlands, ²Meat Science and Genetics, Norsvin, Hamar, Norway *matt.schulte@topigsnorsvin.com

Objectives: Fat quality is a crucial factor in pork production, as it influences the flavor, texture, technological quality, and nutritional value of the meat. Near-infrared spectroscopy (NIRS) provides a quick and non-destructive method for assessing fat quality traits in pig carcasses. It is essential to conduct genetic evaluations of fat quality traits in pigs to enhance meat production and meet consumer demands. Previous research has validated the use of NIRS for the genetic evaluation of fat quality in pigs, and iodine value is the trait of interest in the current study. The objective of this study was to evaluate the variation of estimated genomic breeding values for fat quality traits in male selection candidates of a genetic evaluation program.

Materials and Methods: Iodine value and fatty acid compositions were measured on subcutaneous fat taken from the area between the loin and ham break (sacral vertebrae) of the carcasses from 280 pigs with the use of gas chromatography (GC), and NIRS Spectra was obtained on the same samples using the FOSS FoodScan near-infrared spectrophotometer (850 to 1050 nm) and FOSS XDS near-infrared rapid content analyzer (400 to 2500 nm). Machine learning algorithms (partial least squares regression and modified partial least squares regression methods) were utilized to develop prediction models of spectral data. The traits were assessed in populations comprising 3 distinct pig breeds (Landrace, Duroc, and Yorkshire). Genetic parameters were estimated utilizing statistical models in ASReml-R v4.1.0.176. A dataset of 11,543 animals with NIRS-predicted iodine values, sourced from animals slaughtered or utilized as selection candidates (without phenotypes for fat quality) from two boar test stations (Hamar, Norway and Winnipeq, Canada) were included in the analysis. All animals were genotyped, and estimated breeding values were derived from a genomic evaluation. Due to different test stations and feeding strategies, comparisons across breeds are not presented.

Results: The best equation obtained has a coefficient of determination for cross-validation (R² CV) of 0.97, a root mean square error of a cross-validation (RMSECV) of 0.47, the coefficient of determination for validation (R² val) of 0.95, and root mean square error of prediction (RMSEP) of 0.59 based on spectral data from FOSS FoodScan near-infrared spectrophotometer (850 to 1050 nm). When using these calibrations to predict iodine values for animals assessed, the traits demonstrated high heritability estimates for iodine value, ranging between 0.52 (±0.06) and 0.55 (±0.06). This shows a significant genetic contribution to the variability observed in this trait. Figure 1 illustrates the distribution of estimated breeding values (EBV) for 502 boars from a sire line and 466 boars from a dam line.

Figure 1.

Variation in EBV (breeding value) for 502 and 466 boars from terminal sire and dam lines, respectively, which are male selection candidates tested at boar test stations.

Conclusion: This study provides insights into the genetic evaluation of fat quality in pigs using NIRS. As a result of high precision calibration and high heritability of the fat quality trait, the studies demonstrated the potential of NIRS as a valuable tool for pig breeding programs. As breeding values for NIRS-predicted breeding values are available, genetic selection strategies offer promising opportunities for enhancing fat quality.

Keywords: fat quality, genetics, iodine value, near-infrared spectroscopy, pork

151 LONG-TERM FROZEN STORAGE EFFECTS ON GROUND BEEF ORIGINATING FROM STEERS FED AN OMEGA-3 ENRICHED FINISHING DIET

C. C. Catrett^1,*, A. M. Stelzleni¹, J. S. Drouillard², S. A. Devane¹, G. A. McKinney¹, X. Li¹, D. Alambarrio¹, J. M. Gonzalez¹, ¹Animal and Dairy Science, University of Georgia, Athens, Georgia, United States, ²Animal Science and Industry, Kansas State University, Manhattan, Kansas, United States *cameron.catrett@uga.edu

Objectives: The study objective was to determine effects of long-term frozen storage on oxidation and palatability ratings of ground beef patties originating from steers fed greatOplus® (Nannochloropsis oculata, flaxseed, and wheat middling blend; NBO3 Technologies, Manhattan, KS) during finishing.

Materials and Methods: Black-hided steers (N = 700) were weighed, stratified, allocated to 28 pens (N = 25 head/pen). Pens were randomly assigned to being fed either a conventional finishing diet (CON; n = 14) or a conventional feedlot diet containing 10% (dry-basis) greatOplus® (OMG; n = 14). After 173 d on feed, one steer per pen was randomly selected, transported, and harvested at a commercial abattoir. Forty-eight hours postmortem whole Round and three-piece Chuck subprimals were vacuum packaged and shipped to University of Georgia Meat Science and Technology Center (Athens, GA). On d 21 (Round) and 23 (Chuck) postmortem, primals were coarse and fine ground, producing112 patties(113 ± 2 g, 13-mm thick) per carcass and primal. Patties were flash frozen (−40°C), placed in a white, cardboard box, and stored for 0, 30, 60, or 90 d at−20°C. At each time point, samples were randomly removed, vacuum packaged, and allocated to thiobarbituric acid reactive substances (TBARS) and trained sensory analysis. Data were analyzed using a PROC MIXED procedure of SAS (Cary, NC) as a completely randomized design with a 2 × 4 factorial arrangement and the fixed effects of Treatment, Time, and their interaction. Significance was declared at P ≤ 0.05.

Results: There were no Treatment × Time interactions nor Time main effects for Round and Chuck TBARS values (P > 0.35); however, there were Treatment main effects where at each time point CON patties exhibited elevated TBARS values than OMG patties (P < 0.01). No Treatment × Time interactions nor Treatment main effects were observed for each primal cooked patty parameters and trained sensory analyses (P > 0.16); however, there were Time main effects observed for certain attributes (P < 0.01). Chuck thaw loss and both primal cook loss percentages presented a Time main effect where d 0 patties had increased loss percentages than patties at each other time point (P < 0.01), but values from d 30, 60, and 90 did not differ from each other (P > 0.14). Time main effects occurred for Round beef flavor and off-flavor ratings where d 0 patties had decreased beef flavor identity and reduced off-flavor prevalence than patties from all other time points (P < 0.01), but ratings did not differ between d 30, 60, and 90 (P > 0.30). Chuck beef flavor, cohesion, juiciness, and off-flavor ratings presented a Time main effect where d 0 patties had decreased beef flavor identity, cohesion, juiciness, and off-flavor prevalence compared to patties from d 30, 60, and 90 (P < 0.01); however, ratings did not differ from d 30 to 90 for each palatability attribute (P > 0.15).

Conclusion: Overall, greatOplus® supplementation coupled with long-term frozen storage did not negatively affect ground beef patty oxidation levels and palatability attributes.

Funding Source: The authors would like to thank the Cattlemen’s Beef Board/Beef Checkoff and NBO3 Technologies for providing funding for this project.

Keywords: consumer, finishing diet, frozen storage, ground beef, omega-3 fatty acid

152 EVALUATION OF THREE-DIMENSIONAL (3D) IMAGING TO PREDICT BEEF CARCASS AND PRIMAL COMPOSITION

A. Mendizabal^1,*, B. A. Foraker², J. F. Legako¹, C. Brooks¹, M. F. Miller¹, D. R. Woerner¹, ¹Animal and Food Sciences, Texas Tech University, Lubbock, Texas, United States, ²Animal Sciences, Washington State University, Pullman, Washington, United States *anmendiz@ttu.edu

Objectives: The beef industry has a considerable need for enhanced metrics to assess red meat yield (RMY) and carcass composition, as current USDA yield grades (YG) do not accurately reflect the true variation in value among cattle.Recent research has demonstrated a discrepancy of YG and RMY, and, specifically, the lack of relationship between ribeye area (REA) and carcass muscularity. Previous studies have shown yield grade only explains 34% of the variation in RMY. This study was intended to develop and evaluate models for RMY of beef carcasses and primal composition (% lean, fat, and bone) using three-dimensional (3D) imaging technology.

Materials and Methods: A combination of steers, heifers, and bulls were harvested at Gordon W. Davis Texas Tech University Meat Laboratory (N = 41), following standard industry practices. After harvest, carcasses were chilled for 6 d. During chilling (at least 24 h postmortem), carcasses were 3D imaged as intact sides using the Polycam® software powered by an Apple® iPad Pro 6th generation. Individual carcass cutout data were obtained through a yield test consisting of beef sides fabricated to common product specification. Yield data included weights of trimmed subprimals, bone, fat, and lean trimmings adjusted to 90% lean, all expressed as a percentage of the carcass weight. Adjusted trim was combined with subprimal yield to generate RMY. Cutout data was aggregated by individual primal, then carcass to calculate composition. 3D images were exported as a meshcloud and processed using MeshLab®. Carcass cross-sections were generated at common anatomical locations to determine the cross-sectional area, perimeter, and alpha shape complex. These measurements, along with linear measurements, were utilized to generate prediction models by the application of “all possible combinations” approach, in multiple linear regression.

Results: The results indicate the developed models are highly effective, accurately predicting 96%, 97%, and 95% of the variations in carcass red meat yield, fat percentage, and bone percentage, respectively. Additionally, models accurately explained compositional variation across different beef primal: chuck (97% RMY, 95% fat, 78% bone), rib (88% RMY, 93% fat, 92% bone), loin (98% RMY, 99% fat, 98% bone), and round (87% RMY, 93% fat, 99% bone).

Conclusion: Data derived from beef carcass 3D images can be used in prediction models that can accurately predict carcass and primal RMY and composition, showing a higher predictive ability when compared to YG.

Funding Source: National Cattlemen’s Beef Association.

Keywords: 3D imaging, beef, LIDAR, red meat yield

153 SURVEY OF RESIDUAL NITRITE AND NITRATE IN PROCESSED MEATS FROM SMALL PROCESSORS AND IN MEAT ANALOGUES AT RETAIL IN THE UNITED STATES

S. Sheng^1,*, J. J. Sindelar¹, E. Silva², J. R. Claus¹, ¹Department of Animal & Dairy Sciences, ²Department of Plant Pathology, University of Wisconsin-Madison, Madison, Wisconsin, United States *siyuan.sheng@wisc.edu

Objectives: Nitrite (NO₂⁻) and Nitrate (NO₃⁻) are restricted curing agents that serve as an antimicrobial to inhibit Clostridium botulinum, retard lipid peroxidation, and provide unique cured meat flavor. The amount of added nitrite and nitrate is regulated to a maximum ingoing concentration of 200 and 700 ppm for whole muscle and 156 and 1718 ppm for comminuted products, respectively. Nitrate can naturally be introduced from various sources, including water and ice, non-meat ingredients, and processing aids. The purpose of this study was to evaluate major categories of cured meats for residual NO₂⁻/NO₃⁻ from small and regional meat processors associated with product competitions in 3 geographic locations in the United States. The results provide a NO₂⁻/NO₃⁻ concentration benchmark to enable comparison to previous surveys. This study also determined how water, species of meat, addition of non-meat ingredients and processing methods affect residual NO₂⁻/NO₃⁻. Plant protein meat analogues available at retail stores were surveyed for comparison to traditional processed meat products.

Materials and Methods: A total of 973 processed meat samples were collected by graduate students at the Wisconsin (n = 462), Pennsylvania (n = 291), and California (n = 220) Association of Meat Processors Product Competition from April 2023 to March 2024. Meat analogues (n = 53) were acquired at retail stores in Madison, WI in February 2024. Processed meat and meat analogues were homogenized using a polytron blender with phosphate buffer (pH 7.4) followed by extraction with methanol then injected into an HPLC instrument (ENO-20 nitrite/nitrate analyzer with a reverse phase column). Data were collected using chromatography data collection software (Powerchrome 16.0) and analyzed by R studio (R package 4.3.3.). Multi-linear regression model was applied to evaluate factors that contributed to residual nitrite and nitrate level in processed meats; one-way ANOVA test and pairwise t-test were used to assess statistical difference between each class of processed meats.

Results: NO₂⁻ in samples collected in California, Pennsylvania, and Wisconsin averaged 18.3, 10.4, and 13.8 ppm and NO₃⁻ averaged 8.3, 30.3, and 47.1 ppm, respectively. NO₂⁻ and NO₃⁻ averaged 1.9 and 7.3 ppm respectively in plant protein meat analogues. NO₂⁻ was affected by location (P ≤ 0.001), fermentation or chemical acidification (P ≤ 0.001), species of meat (pork, poultry) (P ≤ 0.001), dehydration (P ≤ 0.01), and inclusion of variety meats (P ≤ 0.05) while NO₃⁻ was affected by location (P ≤ 0.001), species of meat (pork, poultry) (P ≤ 0.001), dehydration (P ≤ 0.01), inclusion of variety meats (P ≤ 0.05), and fine or coarse ground (P ≤ 0.05).

Figure 1.

Factors influencing residual nitrate in processed meats (n = 973).

Conclusion: The study presented comprehensive information for consumers who have interest in residual NO₂⁻ and NO₃⁻ as well as evaluated how processing methods, species of meat, non-meat ingredients, and geographic location correlated with NO₂⁻ and NO₃⁻ in processed meats and meat analogues. Moreover, this study provides a baseline that can be used to compare to previous nitrite/nitrate surveys.

Funding Source: U.S. Department of Agriculture.

Keywords: HPLC, meat analogues, nitrate, nitrite, processed meats

154 VASCULARLY RINSING LAMB CARCASSES WITH CALCIUM CHLORIDE IN COMBINATION WITH ELECTRICAL STIMULATION CAUSES PROTEOLYTIC CHANGES ASSOCIATED WITH MEAT TENDERNESS

N. Pharino^1,*, K. Hwang¹, A. J. Franzen¹, R. E. Campbell², J. R. Claus¹, ¹Department of Animal & Dairy Sciences, University of Wisconsin, Madison, Wisconsin, United States, ²Director of Technical Services, MPSC INC, Hudson, Wisconsin, United States *jrclaus@wisc.edu

Objectives: The study objective was to determine the impact of adding calcium chloride to Rinse & Chill® solution on muscle protein degradation using myofibril fragmentation index methodology.

Materials and Methods: Lambs (total n = 27) of market age were randomly assigned to 3 different carcass vascular rinsing postmortem methods (treatment) which included 1) RC (Rinse & Chill® solution; 98.5% water; balance: glucose, polyphosphates, maltose; 10% live weight), 2) RCA (RC + 0.3 M calcium chloride), and 3) ES-RCA (electrical stimulation followed by RCA). Lambs were humanely stunned and exsanguinated prior to carcass treatment. The sternum was split open to access that pleural cavity. A cannula was inserted into the heart to infuse the rinse solution. For ES-RCA, the carcasses were electrically stimulated for two consecutive 30-s periods (800 milliamps) before the rinse. Skinned and eviscerated carcasses were chilled at 3°C for 24 h before fabrication. Myofibril fragmentation index (MFI) was used to assess proteolytic changes in postmortem muscle¹. Semimembranosus (SM), longissimus (LD), and triceps brachii (TB) muscles were collected, vacuum packaged, and aged for 3 d. The samples were minced and homogenized with MFI buffer (2°C). The sample was centrifuged (1000 × g, 15 min, 2°C), and the supernatant was decanted. The pellet was resuspended and processed again. The resulting pellet was resuspended and standardized to 0.5 mg/mL protein before measuring absorbance (540 nm). The MFI was calculated by multiplying the absorbance by 200. Data were analyzed as split plot design (whole plot factor, carcass treatment) and muscle (split-plot factor).

Results: MFI means were largest (P < 0.05) for the RC carcass treatment in all 3 muscles compared to RCA and ES-RCA. MFI means were not different (P > 0.05) between RCA and ES-RCA in any muscle. Addition of calcium was expected to enhance proteolysis associated with calpains, thus producing a greater MFI than RC. In addition, ES is known to contribute to tenderization. Use of calcium or calcium plus ES resulted in lower Warner-Bratzler shear force (WBS) than RC in the LD². ES with calcium in the SM exhibited lower WBS than RC². Microscopically the supernatant of ES-RCA and RCA treatments appeared to contain more very small myofibrillar fragments than RC. As such these fragments were not retained in the pellet used to determine MFI.

Conclusion: Based on microscopic assessment, inclusion of calcium in the Rinse & Chill® solution may offer packers the opportunity to increase tenderness. The MFI method might not be reliable for assessing tenderness in highly proteolytically tenderized meats. Analysis of the amount of myofibrillar proteins at each MFI step warrants further investigation.

References: ¹Culler, R. D., Smith G. C., & Cross, H. R. 1978. Relationship of myofibril fragmentation index to certain chemical, physical and sensory characteristics of bovine longissimus muscle. Journal of Food Science, 43(4), 1177–1180.

²Franzen, A. J., Pharino, N., Hwang, K., Campbell, R. E., and Claus, J. R. 2024. Influence of carcass vascular rinsing with calcium chloride on non-electrically stimulated and stimulated carcasses on meat quality of lambs. AMSA RMC, Abstract AMSA2024-1247.

Funding Source: University of Wisconsin and MPSC Inc.

Keywords: vascular rinsing, meat tenderness, calcium chloride, electric stimulation, myofibril fragmentation index

156 IS BREAST THE BEST? EVALUATING COOKING RATES AND TIME TO TEMPERATURE BETWEEN DIFFERENT TURKEY PARTS AND SIZES UTILIZING A “HOME COOKING” SCENARIO

S. F. Stickley^1,*, M. M. Prester¹, E. A. Mendez¹, A. V. Carlson², M. D. Chao¹, M. D. Zumbaugh¹, T. G. O’Quinn¹, J. L. Vipham¹, ¹Animal Sciences and Industry, Kansas State University, Manhattan, Kansas, United States, ²Global Food Safety Research & Scientific Services, Cargill Inc., Wichita, Kansas, United States *stickleysf1@gmail.com

Objectives: Cooking instructions for whole turkeys recommend a final internal temperature of 73.9°C (165°F) taken from the breast. However, few studies have evaluated whether an alternative part temperature would be more indicative of overall whole turkey lethality. Therefore, the objective of this study was to establish the cooking rate of 5 individual parts (i.e., breast, thigh, wing pit, drum, and back) and evaluate differences in cooking rates between common retail birds (i.e., 12 to 16 lb) and large birds (24 to 30 lb), as well as to determine if breast temperature is a true “gold standard.”

Materials and Methods: A total of 40 birds were utilized for the study, with 20 birds for each treatment group (large vs. small). Validated cooking methods were utilized to cook each bird in a traditional retail oven. Birds were cooked to a final temperature of 73.9°C, per instructions. Cooking temperature was recorded using 5 type K ovenable thermocouple probes with real-time loggers for each of the 5 parts (breast, thigh, wing pit, drum, and back) every 5 min, and one air probe was used to record actual oven temperature. Data was recorded as temperature in the oven and was utilized to establish the rate of cooking for each part (73.9°C initial temperature/time; part rate), the final temperature of each part when all parts reached 73.9°C (final temperature), and the temperature of each part when breast reached 73.9°C (gold standard).

Results: Analysis revealed a significant interaction between bird size and part (P = 0.004). For small birds, the fastest (P < 0.0001) part rate was observed in the breast (0.51°C/minute), while the slowest (P < 0.0001) rate was observed in the wing pit (0.34°C/minute). No difference (P > 0.05) in part rate was observed among the breast, drum and thigh. Conversely, large birds had a faster (P < 0.0001) part rate in the drum (0.40°C/minute) as compared to other parts. Interestingly, the wing pit remained the part with the slowest (P < 0.0001) part rate (0.25°C/minute) in large birds. Data for final temperature demonstrated a significant difference between each of the 5 parts for each treatment (P < 0.0001), with small birds having a higher (P < 0.0001) final temperature in the wing pit and drum as compared to large birds, which had a higher (P < 0.0001) final temperature in the back, thigh and breast. Finally, for comparisons with the gold standard, large birds had a significantly higher (P < 0.0001) drum temperature and a significantly lower (P < 0.0001) wing pit temperature than all other parts when breast was at 73.9°C. This varied in small birds, with wing pit being the only part that had a significantly lower temperature as compared to all other parts when breast was at 73.9°C (P < 0.0001).

Conclusion: Results from this study indicate that breast may not serve as the most accurate measurement for overall turkey lethality. Additionally, data demonstrated that all observations were influenced by both the size of the bird and the part being measured. In both large birds and small birds, wing pit took significantly longer to reach 73.9°C than all other parts and was significantly lower in temperature when compared to the breast gold standard. Additionally, data demonstrated smaller birds cooked more consistently, with shorter time to final temperature.

Keywords: cooking rates, cooking temperatures, lethality, turkey

157 ENGINEERING BIOPLASTICS WITH BIOPOLYMERS AND ANTIMICROBIALS TO IMPROVE LISTERIA MONOCYTOGENES FOOD SAFETY IN READY-TO-EAT PRODUCTS OVER 12 WEEKS OF STORAGE

K. Sierra^1,*, L. J. Guzman¹, V. Tashiguano¹, T. Black¹, J. Valenta¹, L. Garner¹, A. Morey¹, ¹Poultry Science, Auburn University, Auburn, Alabama, United States *kzs0166@auburn.edu

Objectives: Food packaging contributes to environmental pollution and is a concern among customers, pushing the food industry to innovative, sustainable, and biodegradable plastic-alternative packaging materials. Incorporating biomolecules from agricultural waste to improve mechanical properties and antimicrobials to improve food safety and shelf life in these innovative packaging can increase their market acceptance. The research was conducted with the following objectives: 1. Develop a plastic-alternative packaging film with biopolymer from chicken skin; 2. Incorporate antimicrobials and study their effects on the mechanical properties of the film; 3. Evaluate the efficacy of the antimicrobial film against Listeria monocytogenes (LM) and spoilage of ready-to-eat poultry products.

Materials and Methods: Bioplastic films with a base formulation of 3% Chicken Gelatin + 4% Nanocellulose, starch (1%), glycerol (6%), and water (85%) were developed with either 0, 1, or 3% lactate diacetate (LD) as an antimicrobial. The LD was incorporated into the dried cast films. Mechanical properties were analyzed for tensile force, Young’s modulus, elongation, and punching force, using Exponent Stable Micro System Software Package. For antimicrobial analysis, films with 3 antimicrobial treatments (0, 1, and 3% LD) and one control treatment (without any packaging) were tested. RTE bologna was inoculated with ∼6 logs of LM. The antimicrobial side of the film was laid on top of the inoculated deli surface, vacuum packaged, stored (4°C), and sampled weekly for 12 wk (3 samples × 2 trials, n = 336). Deli + film was stomached (Buffer Peptone Water 1:1w/w, for 1 min), serially diluted, and spread plated (0.1 mL) on Modified Oxford Agar and incubated at 37°C for 24 h. For spoilage analysis, uninoculated bologna was packaged with the same treatments and parameters as stated above and conducted at 0 h and then weekly for 12 wk (3 repetitions × treatment × trial, n = 96). The uninoculated samples were spread-plated on plate count Agar (PCA) and incubated aerobically (48 h at 37°C). A separate set of PCA and Mann Rogosa Sharpe (MRS) agar plates was incubated anaerobically (72 h at 37°C) to anaerobic plate and lactic acid bacteria counts, respectively. Colonies were counted and reported as log CFU/g. Data were analyzed (ANOVA-SAS) with significant mean differences at (P ≤ 0.05).

Results: The addition of LD to edible films with collagen significantly reduced (P ≤ 0.05) its mechanical properties. The LD bioplastic acted as a bacteriostat, a bactericide (decrease of ∼2 logs CFU/g), and a bacteriostat for weeks 0–4, 5–7, and 7–12, respectively. For the Spoilage analysis, the addition of LD to edible films reduces ∼1 log CFU/g after 12 wk of storage.

Conclusion: Edible films with chicken skin collagen and LD offer a promising alternative for food packaging and extend the shelf life of RTE products.

Funding Source: Auburn University

Keywords: antimicrobials, bioplastics, biopolymers, Listeria monocytogenes, ready-to-eat products (RTE)

158 METHODS FOR ASSESSING THE DIVERSITY AND PATHOGENICITY OF SALMONELLA IN SWINE LAIRAGE PENS

W. Wu^1,*, A. Abrego², R. L. Jimenez³, G. Houston⁴, M. Miller⁴, D. Brichta-Harhay¹, M. Brashears³, S. E. Gragg², J. W. Schmidt¹, ¹Meat Safety and Quality Research Unit, US Meat Animal Research Center, USDA-ARS, Clay Center, Nebraska, United States, ²Department of Animal and Dairy Sciences, University of Wisconsin-Madison, Madison, Wisconsin, United States, ³Department of Animal and Food Sciences, Texas Tech University, Lubbock, Texas, United States, ⁴Technical Services Department, Triumph Foods, St. Joseph, Missouri, United States *john.w.schmidt@usda.gov

Objectives: Salmonella colonizes the swine gastrointestinal tract and is present in processing plant holding (“lairage”) pens. Human pathogenic potential varies significantly between Salmonella subtypes. Salmonella with ≥4 genes associated with highly pathogenic Salmonella (HPS) are theorized to pose significant human pathogenic potential. Understanding the relationships between HPS occurrences in swine finishing environments, lairage, and processing environments are critical for developing pre-harvest mitigations. The goal of this study was to determine the abilities of ropes masticated by swine, pen floor MicroTally swabs, and pen floor boot sock swabs for detecting the diversity of HPS genotypes present in lairage pens.

Materials and Methods: Each of 15 lairage pens at a commercial swine processing establishment were sampled. A 24-inch length cotton rope was hung at swine shoulder height for 30 min in each populated pen. Following pen depopulation, ½ of a Fremonta Microtally Swab (MT-S100) pre-wetted with of Buffered Peptone Water (BPW) was placed on a clean mop head, and the swab was dragged in a “W” pattern that sampled approximately 10–15 feet at the front of the pen. This process was repeated in the middle and back of each pen for a total of 3 Microtally swab samples per pen. Then clean plastic bootcovers were donned and Hardy Diagnostics Envirobooties pre-soaked in skim milk (EB50) were placed over each bootcover. The pen was then walked in an approximately hourglass pattern while ensuring the most soiled areas were traversed. Then each boot sock was placed in a separate bag. Each sock was processed as a separate sample. Ropes were suspended in BPW, and an aliquot of suspension was enriched with BAX-MP. Each Microtally Swab was suspended in BAX-MP and enriched. Each boot sock was suspended in BPW, and an aliquot of suspension was enriched with BAX-MP. Immunomagnetic beads were used to separate Salmonella from the primary enrichment for secondary enrichment in Rappaport Vassiliadis Soya (RVS) broth. RVS enrichments were swabbed on Brilliant Green Sulfa and Xylose Lysine Deoxycholate agars. From each sample, 4 presumptive Salmonella colonies were screened for the presence of the 8 genes associated with HPS by multiplex PCR. The combinations of sample methods listed in Table 1 were analyzed for their abilities to identify diverse HPS genotypes and pen prevalence of Salmonella harboring ≥4 HPS genes.

Results: Salmonella with ≥4 HPS genes were detected in 14 of 15 pens. Rope and 1 Microtally Swab methods failed to detect Salmonella with ≥6 HPS genes (Table 1). The 2 boot socks method detected Salmonella with all 8 HPS genes in 3 pens. Eight HPS genotypes were detected across the 15 pens. The 2 boot sock method was the only method that detected 8 HPS genotypes.

Conclusion: The study indicated that the most efficient method for detecting the diversity of Salmonella present in swine lairage pens was a pair of boot socks that are cultured for Salmonella separately.

Funding Source: Foundation for Meat and Poultry Research and Education, Agricultural Research Service National Program 108—Food Safety.

Keywords: lairage, pathogenicity, pre-harvest, Salmonella, swine

159 PREVALENCE AND ANTIBIOTIC RESISTANCE OF SALMONELLA AND CAMPYLOBACTER IN RETAIL CHICKEN COLLECTED IN SOUTHERN CALIFORNIA IN 2020

Y. Feng^1,*, K. Y. Lee², E. R. Atwill², M. Pitesky², K. Lavelle², M. E. Gaa², J. Sebti², Y. Liu¹, X. Li², X. Yang¹, ¹Department of Animal Science, ²School of Veterinary Medicine, University of California, Davis, Davis, California, United States *yuyfeng@ucdavis.edu

Objectives: The use of antibiotics in poultry production might contribute to the development of antibiotic-resistant bacteria (ARB) that can be transmitted to people by consuming contaminated meat. This study assessed the prevalence and antibiotic resistance of two common foodborne pathogens, Salmonella and Campylobacter, in retail chicken meat samples collected by the National Antimicrobial Resistance Monitoring System (NARMS) from Southern California in 2020.

Materials and Methods: In 2020, 5 chicken products (breasts, wings, legs, thighs, or whole chicken) were purchased monthly from randomly selected grocery stores in Southern California. The sampling was interrupted from April through June due to the COVID-19 pandemic, resulting in a total of 45 chicken products collected. Salmonella and Campylobacter were tested from each sample using the NARMS Retail Meat Surveillance Protocol. Antimicrobial susceptibility testing (AST) and whole genome sequencing (WGS) were performed on all isolates. Antibiotic-resistant genes were identified from the ResFinder database. Statistical tests, including Fisher’s exact test for bacterial prevalence and the t-test for antibiotic resistance genes (ARG), were conducted in R studio with an alpha level of 0.05 to determine significance.

Results: Salmonella and Campylobacter were isolated from 24.4% (11) and 33.3% (15) of the samples, respectively. There was no significant difference (P > 0.05) in the prevalence detected among the various meat cuts, collection months, and package claims regarding antibiotic use. The predominant species of Campylobacter was C. jejuni (80%; 12), while the primary serotype for Salmonella was S. Kentucky (81.8%; 9). Among all the Salmonella isolates, 45.5% (5) showed phenotypical resistance to at least one antimicrobial drug, with 36.4% (4) specifically resistant to tetracycline. The WGS results indicated that 45.5% (5) of Salmonella isolates harbored genes conferring the resistance to tetracycline. While 63.64% (7) Salmonella isolates contained at least two genes associated with aminoglycoside resistance, only 18.2% (2) expressed this resistance phenotypically. Among Campylobacter isolates, 80.0% (12) demonstrated phenotypical resistance to at least one antimicrobial drug in the quinolone or tetracycline class. Although 53.3% (8) of isolates carried tetracycline resistance genes, no quinolone resistance genes were detected. Notably, the package claims regarding antibiotics use did not (P > 0.05) lead to a difference in the number of ARG in Salmonella (3 genes per isolate) and Campylobacter (1 gene per isolate).

Conclusion: The study suggests that antimicrobial-resistant Salmonella and Campylobacter are consistently present in retail chicken, irrespective of the chicken cut type or claims of antibiotic-free on package. Despite the small sample size, the slight discrepancy between the genotype and phenotype suggests that genomic data and phenotypical data should be evaluated periodically for accurate risk assessment for antibiotic resistance. This study emphasizes the importance of the NARMS Retail Food Surveillance on monitoring antibiotic resistance of foodborne pathogens in retail foods.

Funding Source: This work was made possible, in part, by the U.S. Food and Drug Administration through grant 1U01FD007162. Views expressed in this presentation do not necessarily reflect the official policies of the Department of Health and Human Services, nor does any mention of trade names, commercial practices, or organization imply endorsement by the United States Government.

Keywords: antibiotic resistance, Campylobacter, chicken, prevalence, Salmonella

160 ASSESSING THE EFFICACY OF LIQUID SMOKE IN COMBINATION WITH ORGANIC ACID SALTS IN INHIBITING LACTIC ACID BACTERIA AND LISTERIA MONOCYTOGENES GROWTH IN FRANKFURTERS

S. Wason^1,*, K. Rumbaugh¹, J. Saha¹, R. Weyker², P. Ludtke², S. Kumar¹, ¹Food Preservation & Protection, ²Meat Applications, Kerry, Beloit, Wisconsin, United States *surabhiwason25@gmail.com

Objectives: Different combinations of Cloud S-6 (liquid smoke) and Provian K (potassium acetate/diacetate blend) were assessed to prevent the outgrowth of lactic acid bacteria (LAB) and Listeria monocytogenes in a frankfurter application.

Materials and Methods: Five treatments including control (0.5 to 1.5% Cloud S-6 + 0.55% Provian K) were prepared for microbiological challenge test and sensory panel respectively (Table 1). The samples (2 frankfurters in-package) were inoculated with either 5-strain cocktail of L. monocytogenes or Lactobacillus sakei. Following bacterial attachment, the frankfurters were vacuum packaged and stored at 4°C and sampled for up to 120 d. At each sampling, frankfurters were homogenized using a stomacher and plated onto Modified Oxford medium for L. monocytogenes and Man, Rogosa and Sharpe for L. sakei enumeration. Failure of antilisterial capacity was assessed at 2 log CFU/g outgrowth while spoilage limit of 7 log CFU/g or visual spoilage characteristics was set for L. sakei. The result was compared using one-way ANOVA (P < 0.05). Sensory analysis was conducted to determine the sensorial impact of the Cloud S-6 at 3 usage levels on key frankfurter attributes. Samples were blinded with 3-digit codes and compared to reference (Provian K @ 0.55%). Panelists used a 9-point relative to reference scale to determine how different and the directionality of that difference (more or less) for key attributes. The data were collected using EyeQuestion version 5.07.15 and analyzed and charted using the Kerry Data Analysis Software.

Results: Inoculation level of 2–2.5 log CFU/g of L. monocytogenes was achieved on day 0 for all the treatments. The control treatment exhibited fastest outgrowth (>2 log CFU/g) of L. monocytogenes by 21 d at 4°C. The 0.55% Provian K treatment significantly (P < 0.05) controlled L. monocytogenes outgrowth (2 log CFU/g) until 49 d. Addition of 1–1.5% Cloud S-6 further extended the number of days to reach 2 log outgrowths by more than >63 d. For L. sakei challenge study, the control sample (no antimicrobial) spoiled by day 15, while 0.55% Provian K was effective in controlling the spoilage with L. sakei counts below 7 log CFU/g until days 22. In addition, combination of 1.0% Cloud S-6 and 0.55% Provian K significantly improved the shelf life of frankfurters by controlling the spoilage to >35 d at 4°C. In terms of sensory perception, the meaty, smoky, and umami character do not show a trend of increased perception looking across the 3 level of Cloud S-6 on day 7. However, as the samples age, there appears to be a trend of lower smoky flavor especially at the lowest level compared to the reference (0.55% Provian K).

Conclusion: At storage temperature of 4°C, 1–1.5% Cloud S-6 was effective in enhancing the efficacy of 0.55% Provian K by providing significantly higher shelf life of frankfurters when combined as compared to Provian K by itself. Overall, 1.0% Cloud S-6 and 0.55% Provian K showed good sensorial performance in terms of meaty, smoky, umami, and firmness.

Keywords: smoke, organic acids, frankfurters

161 EVALUATION OF COMMERCIALLY AVAILABLE LOW-SODIUM ORGANIC ACID SALTS EFFICACY AGAINST LISTERIA MONOCYTOGENES IN UNCURED TURKEY DELI MEAT SYSTEMS

K. Rumbaugh^1,*, R. Furbeck¹, J. Saha¹, E. Heintz², S. Kumar¹, ¹Food Protection and Preservation, Kerry, Beloit, Wisconsin, United States, ²Food Protection and Preservation, Niacet - A Kerry Company, Tiel, Netherlands *kaylee.rumbaugh@kerry.com

Objectives: The purpose of this study was to evaluate the antilisterial efficacy of sodium and potassium based organic acid salts in reformed uncured turkey deli meat at refrigerated storage (4°C).

Materials and Methods: Seven treatments of reformed uncured turkey deli meat were manufactured (0.25, 0.50, 0.75% potassium acetate/diacetate dry blend, 1.25, 2.50, and 3.50% liquid potassium lactate/sodium diacetate commercial blend) and uncured control (no antimicrobial). Four 25-gram slices were aliquoted into vacuum bags, inoculated with (2.5 log₁₀ CFU/g) Listeria monocytogenes, vacuum packaged, stored at 4°C, and sampled for up to 120 d. At sampling, duplicates of each treatment were removed from storage, homogenized with a stomacher, and plated onto Modified Oxford media for enumeration. Sample failure of antilisterial capacity was assessed at 2 log₁₀ CFU/g outgrowth. Treatment performance was compared using ANOVA in SAS JMP 17. Significance in this study was set at (P < 0.05).

Results: Inoculation level of ∼2.5 log₁₀ CFU/g of L. monocytogenes was achieved on day 0 for all treatments. The potassium acetate/diacetate treatments (0.25–0.75%) greatly enhanced shelf life compared to the control (which reached 2 log₁₀ CFU/g outgrowth at 21 d). The highest concentrations of potassium acetate/diacetate and potassium lactate/sodium diacetate commercial blend treatments exhibited ongoing control over L. monocytogenes outgrowth (<2 log₁₀ CFU/g) and significantly extended the shelf-life during storage (>42 d). Table 1 represents the growth of L. monocytogenes on the control and treatments over time on uncured turkey stored at 4°C.

Conclusion: Replacing traditional sodium containing organic acid blends with potassium based organic acid salts would decrease the sodium concentration in meat and other food products. The potassium based organic salt blend could be used to help reduce sodium while still providing significant shelf-life extension in deli meat systems contaminated with L. monocytogenes. With upcoming front-of-the-pack labeling requirements in Canada for sodium reduction guidelines, this would help processors to look for alternatives with no/low sodium. The performance is comparable to conventional commercial solutions (potassium lactate/sodium acetate) but, as it is a dry product, at levels 3 to 5 times lower (0.75% compared to 3.50%). As a dry solution, processors would have a more sustainable option, requiring less freight without compromising their food safety.

Keywords: acetate, Listeria monocytogenes, microbiology, poultry, sodium reduction

162 SOURCES OF SALMONELLA CONTAMINATION OF PORK HEAD AND CHEEK MEAT

K. Marcum^1,*, S. E. Gragg¹, ¹Animal and Dairy Sciences, University of Wisconsin-Madison, Madison, Wisconsin, United States *sgragg@wisc.edu

Objectives: Salmonella prevalence of pork head and cheek meat trim is reportedly over 60%, but little research has thoroughly investigated the source of contamination. Head and cheek meat is removed from the head and the process often includes exposure to tonsils and lymph nodes. Previous research has demonstrated that Salmonella can be harbored in swine lymph nodes and tonsils; thus, these tissues may directly contaminate the processing environment and/or head and cheek meat. This study aims to characterize Salmonella contamination, including opportunities for cross-contamination, of pork head and cheek meat during the deboning and trimming process by collecting head lymph nodes, tonsils, trim, environmental swabs, and carcass swabs.

Materials and Methods: At a commercial market hog processing facility, pork head and cheek contamination was investigated using exploratory sampling in processing areas associated with the head. The following sample types were collected: lymph nodes from heads, tonsils, sponge swabs of split and intact heads (including mouths) at various stages of processing, and a variety of environmental samples using sponge swabbing and MicroTally sampling techniques. Cellulose sponges were hydrated with 10 mL of buffered peptone water (BPW) and MicroTally swabs were dry prior to sampling. Lymph nodes and tonsils were trimmed of fat and fascia, boiled for 3 to 5 s, pulverized, and homogenized with 80 mL of BAX MP media. All trim was collected and processed as a head and cheek meat trim sample by homogenizing 375 grams (+/− 15 grams) with 1.5 L prewarmed (42°C) BAX MP media. Each carcass swab was homogenized with 50 mL of BPW, and environmental samples were homogenized with 225 mL pre-warmed (35°C) BPW. Following incubation, samples were analyzed using the BAX® System Real-time PCR Assay for Salmonella to detect the presence of Salmonella.

Results: Salmonella was not detected in head lymph nodes (n = 53). Of the 36 tonsils collected, 9 (25%) were positive for Salmonella. The following trim and carcass swab samples were positive for Salmonella: head and cheek meat trim (n = 2/2; 100%), sponge swabs of heads (n = 3/15; 20%), and a sponge swab of the mouth while on the processing line (n = 4/5; 80%). A total of 32 environmental samples were collected, and 56.3% (n = 18) were positive for Salmonella, including the following sample types: head spikes (n = 1/6; 16.7%), tongue X-ray conveyor (n = 1/1; 100%), tongue removal stand (n = 2/2; 100%), tongue conveyor (n = 2/2; 100%), head elevator conveyor (n = 4/4; 100%), and the head bone table and conveyor (n = 8/8; 100%).

Conclusion: Salmonella was recovered from the tonsils, mouth swabs, and environmental samples associated with the head, particularly those that come into contact with the tongue. None of the tonsils were intact at the time of collection, suggesting that tonsils are disturbed during processing and may serve as a source of cross-contamination. The recovery of Salmonella from samples associated with the mouth suggests that exposure to the tongue or mouth during processing may contaminate the environment, thereby cross-contaminating heads and leading to head and cheek meat contamination. Additional sampling is necessary to demonstrate the repeatability of these contamination points. Salmonella serotyping and whole genome sequencing is necessary to pinpoint contamination sources and opportunities for subsequent mitigation efforts more accurately.

Funding Source: Food Research Institute, University of Wisconsin-Madison, Madison, WI

Keywords: cheek meat, head meat, pork, Salmonella, trim

163 ENTERING THE TRANSFER PORTAL: ESTIMATING SALMONELLA TRANSFER RATES BETWEEN INOCULATED GROUND TURKEY AND FOOD CONTACT SURFACES WITH LOW AND HIGH LEVELS OF CONTAMINATION

C. A. Effling^1,*, M. O. Tzirin¹, M. B. Paredes¹, A. V. Carlson², M. D. Chao¹, M. D. Zumbaugh¹, T. G. O’Quinn¹, J. L. Vipham¹, ¹Animal Sciences & Industry, Kansas State University, Manhattan, Kansas, United States, ²Global Food Safety Research and Scientific Services, Cargill, Wichita, Kansas, United States *ceffling@ksu.edu

Objectives: Outbreak data has demonstrated that ground turkey is a common reservoir for Salmonella. At home cross-contamination between ground turkey and food-contact surfaces can greatly contribute to the risk of salmonellosis among consumers. Recently, studies have demonstrated that the level of Salmonella within food products impacts the likelihood of contracting salmonellosis. However, little research has evaluated the impact of Salmonella level on cross-contamination of common kitchen surfaces. Therefore, the objective of this study was to evaluate the effect of different Salmonella inoculation levels on Salmonella transfer to common food-contact surfaces.

Materials and Methods: A total of 30 retail ground turkey packages (1 lb) were randomly assigned to 2 treatment groups (n = 15), high (4 logs) or low (2 logs) inoculation level of Salmonella Kentucky. From each package, 25 g was weighed prior to inoculation and used as a negative control. The remaining amount was inoculated based upon treatment and placed into a KitchenAid mixer and mixed on low for 1 min. Positive controls were obtained by weighing 25 g of inoculated turkey from the mixer bowl. From the remaining inoculated ground turkey, four 100 g balls were formed using a micro-tally mitt. Balls were then pressed into patties on a plastic cutting board. Samples were collected from the mixing bowl (sponge swab with 10 mL buffered peptone water), the micro-tally mitt, the cutting board (sponge swab with 10 ml buffered peptone water), and the patty (25 g sample). Positive and negative controls, as well as the patty samples, were homogenized by stomaching samples with 225 mL of peptone water for 1 min, while micro-tally mitts were stomached with 90 mL of peptone water. Serial dilutions were prepared for all samples and plated in duplicates onto EB Petrifilm count plates and incubated. A Realtime PCR system (BAX) was utilized for Salmonella detection on all samples.

Results: For detection, Salmonella was present on all sample types, excluding the negative control, regardless of inoculation level. Overall results demonstrated a difference in the Salmonella transfer between low and high inoculation treatments (P < 0.0001). Moreover, an interaction was observed between treatments and surface type (P < 0.0001), indicating that Salmonella transfer was dependent upon inoculation level on the varied surface types. No differences were observed between the positive control and patty for both the high and low treatments. In the low treatment, differences were only observed between patty and mitt samples, as compared to cutting board and bowl samples (P < 0.0001). Conversely, the high inoculation treatment showed differences in Salmonella transfer between patty, mitt, cutting board, and bowl samples (P < 0.0001).

Conclusion: This study indicates that inoculation level and surface type impact the cross-contamination of Salmonella. Patties had the highest level of Salmonella for both treatments (P < 0.0001), followed by mitts, indicating that a majority of contamination remains in the product and can be easily transferred to hands. More research is necessary to evaluate additional surface types, serotypes, and cooking practices to understand the risk of Salmonella cross-contamination in consumer kitchens.

Funding Source: The Dr. Mark and Kim Young Undergraduate Research Fund in Animal Science

Keywords: cross-contamination, levels, Salmonella

164 INVESTIGATING THE CORRELATION BETWEEN SALMONELLA PROFILES AND MICROBIAL COMMUNITY MEMBERSHIP ON FABRICATED PORK CUTS FROM A COMMERCIAL PROCESSING FACILITY

J. A. Brown^1,*, S. C. Ricke¹, ¹Department of Animal & Dairy Sciences, Meat Science and Animal Biologics Discovery, University of Wisconsin-Madison, Madison, Wisconsin, United States *jabrown35@wisc.edu

Objectives: It is estimated that 12.8% of foodborne Salmonella illness are attributed to pork products. Despite the use of interventions, outbreak data suggests that some populations of Salmonella are able to survive and cause illness in consumers. The objective of this study was to qualitatively and quantitatively evaluate the Salmonella populations present on fabricated pork cuts and identify any correlations to the overall microbiota.

Materials and Methods: Product samples were collected from a single commercial market hog processing facility twice a day, 2 days a week for a 4-wk period. At each sampling time 3 fabricated cuts, picnic shoulder, back rib, and tenderloin, were collected from the right side of one carcass (n = 48). Qualitative analysis was performed by combining 325 g of meat, cut from the external surface of the product, with 975 mL of pre-warmed BPW. The mixture was homogenized, incubated at 42°C for 18 to 24 h, and analyzed for Salmonella using Gene-Up SLM2 kit (limit of detection [LOD] 1). Quantitative analysis was performed by homogenizing 25 g of meat with 125 mL of pre-warmed BPW. The homogenate (40 mL) was transferred to a conical tube and centrifuged to remove large debris and pellet bacteria. The pellet was then resuspended, processed, and analyzed using Gene-Up Quant Salmonella kit (LOD10). A portion of each homogenate was shipped to UW-Madison, where it was enriched and isolated, and presumptive positives were confirmed and serotyped. Genomic DNA was extracted from the quantitative homogenate, 16S rRNA gene sequencing was performed on an Illumina MiSeq, and analyzed in QIIME2. Salmonella prevalence data was analyzed as a generalized linear model with chi-squared tests for significance (P ≤ 0.05). All quantitative Salmonella data was reported below LOD10; therefore, no statistical analyses was performed. Statistical significance of α- and β-diversity metrics were determined using Analysis of variance and ADONIS, respectively, and ANCOM was used to identify differentially abundant taxonomic groups (P ≤ 0.05, q ≤ 0.05).

Results: Fourteen samples were found to be positive for Salmonella (29.2%). Prevalence was impacted by both time of day (P = 0.05) and product type (P = 0.05), with the majority of the positive results being collected later in the shift (10/14) and on tenderloins (8/14). Six serovars were isolated, with a monophasic variant of Salmonella Typhimurium (4,[5],12:i:-), Derby, and Panama being observed most frequently. Sequencing data did not identify a strong correlation between microbial community membership and Salmonella prevalence; however, the phyla Campilobacterota was identified as being differentially more abundant on tenderloin samples, suggesting this product type may be more exposed to a variety of contaminants during processing.

Conclusion: The prevalence rate of Salmonella identified in this study highlights the need for effective and targeted intervention strategies during pork fabrication. The increased prevalence observed later in the shift suggests that cross contamination is likely contributing to the movement of Salmonella through the processing environment and the variation in prevalence associated with product type identifies areas of vulnerability.

Funding Source: This work was financially supported in part by the Wisconsin Alumni Research Foundation.

Keywords: fabricated pork, microbiota, prevalence, Salmonella

165 EFFECT OF NOURISHIELD D4010 ON OUTGROWTH OF SPOILAGE FLORA AND SLIME-FORMING LEUCONOSTOC MESENTEROIDES IN FRESH POULTRY

S. Potkamp^1,*, E. Heintz¹, S. Kumar², ¹Food Protection & Preservation, Kerry, Wageningen, Netherlands, ²Food Protection & Preservation, Kerry, Beloit, Wisconsin, United States *simone.potkamp@kerry.com

Objectives: Determine effectiveness of Nourishield D4010, a clean-label multifunctional system consisting of vinegar and an edible plant extract, on outgrowth reduction of spoilage bacteria and slime-forming Leuconostoc mesenteroides in fresh poultry.

Materials and Methods: For determination of outgrowth of background flora, chicken breasts obtained from a local supermarket were blended into a homogeneous mixture using a clean and sanitized kitchen processor. Afterwards, the following eleven treatments were prepared by blending the meat with the ingredients: control without preservatives, 0.5% IsoAge DV110, 0.6% IsoAge DV110, 0.6% IsoAge DV110+100 ppm rosemary extract (60% carnosic acid), 0.75% IsoAge DV110, 0.9% IsoAge DV110, 0.5% Nourishield D4010, 0.6% Nourishield D4010, 0.6% Nourishield D4010+100 ppm rosemary extract (60% carnosic acid), 0.75% Nourishield D4010, and 0.9% Nourishield D4010. For the inoculated study using Leuconostoc mesenteroides, each chicken breast was first decontaminated by dipping in 100% ethanol and passing it through a flame. Decontaminated chicken was blended with preservatives to obtain the same 11 treatments. The different treatments were inoculated with a two-strain slime-producing Leuconostoc mesenteroides inoculum, targeting 2 to 3 log(CFU/g). All treatments for both studies were packed in portions of approximately 15 g in sterile plastic bags and stored at 4°C for 28 d. Samples were plated at t = 0, 3, 7, 10, 14, 17, 23, and 28 d. At each sampling point, samples for spoilage flora were plated onto TSA (total plate count), MRS (lactic acid bacteria), and VRBG (Enterobacteriaceae) agar. Inoculated samples were plated on MRS agar. Spoilage threshold for background flora was assessed at 6 log(CFU/g) outgrowth while spoilage limit for samples inoculated with L. mesenteroides was set at 7 log(CFU/g) due to visual spoilage characteristics of slime formation. Differences between treatments were compared using one-way ANOVA (P < 0.05).

Results: For total plate count, control samples reached the spoilage threshold of 6 log(CFU/g) after 5 d. All treatments containing preservatives show significant (P < 0.05) reduced outgrowth compared to the control, where 0.9% Nourishield D4010 is exhibiting the best antimicrobial performance. All samples containing different dosages of IsoAge DV110 reached a spoilage level of 6 log(CFU/g) within 10 to 12 d, whereas all samples containing different dosages of Nourishield D4010 reached spoilage after 12 to 17 d. Enterobacteriaceae reached the spoilage limit (6 log(CFU/g)) after 7 d, whereas all samples containing preservatives show significant (P < 0.05) reduced outgrowth, reaching 5.9–6.2 ± 0.3 log(CFU/g) after 17 d. Control samples without preservatives reached spoilage threshold (7 log(CFU/g)) after 8 d. Addition of 0.5–0.9% IsoAge DV110 increases the shelf life to 12 to 14 d. 0.75% and 0.9% of Nourishield D4010 showed a significant (P < 0.05) increase in shelf life by reaching 7 log(CFU/g) after 19 and 23 d, respectively. For none of the tested microorganisms a significant (P < 0.05) additional effect of 60 ppm of carnosic acid was seen compared to 0.6% IsoAge DV110 or Nourishield D4010 alone.

Conclusion: The results of this study demonstrate the possibility to increase the shelf life of fresh chicken using a clean-label multifunctional system of a plant extract and vinegar, Nourishield D4010.

Keywords: fresh poultry, Leuconostoc, preservation, slime formation, spoilage

166 PREDICTING SALMONELLA RISK IN GROUND TURKEY: POTENTIAL RISK FACTORS AND ASSESSMENT OF PREDICTIVE ACCURACY

M. O. Tzirin^1,*, E. A. Mendez¹, M. B. Paredes¹, A. V. Carlson², J. A. Byrd³, S. F. Applegate⁴, N. M. Bello⁵, M. D. Zumbaugh¹, T. G. O’Quinn¹, J. L. Vipham¹, ¹Animal Sciences and Industry, Kansas State University, Manhattan, Kansas, United States, ²Global Food Safety Research & Scientific Services, Cargill Inc., Wichita, Kansas, United States, ³Southern Plains Agricultural Center, USDA-ARS, College Station, Texas, United States, ⁴Market Development, Hygiena, Camarillo, California, United States, ⁵Agricultural Research Service Northeast Area, USDA-ARS, Beltsville, Maryland, United States *marvintzirin@ksu.edu

Objectives: U.S. surveillance data links Salmonella to multiple outbreaks from ground turkey. Moreover, USDA-FSIS has recently increased efforts to minimize the risk of salmonellosis associated with poultry products. The objective of this study was to utilize detection and quantification data collected throughout the turkey supply chain to identify potential risk factors to predict high-risk Salmonella contamination in ground turkey.

Materials and Methods: From September 2022 to January 2024, 66 commercial turkey flocks were sampled across 3 levels of the supply chain (farm, early harvest, and processing). Samples comprised of 10 sources, including bootie pairs, feathers, and fan dust swab samples (farm); trailer swabs, paw swabs, and vent swabs (early harvest); and livers, lungs, ceca, and ground turkey (processing). Every sample was tested for Salmonella detection (3,958 samples) based on the BAX® System Real-Time PCR Assay. Quantification was performed on positive samples (812) utilizing the BAX System SalQuant® assay. Ground turkey Salmonella detection and quantification results were used to classify flocks as low-risk (no positives), medium-risk (at least one sample at 1–10 CFU/g), or high-risk (at least one sample at >10 CFU/g). A generalized linear mixed model approach was used to predict Salmonella risk in ground turkey. Explanatory variables considered were median and maximum quantification values and proportion of positive samples for each sample type. Variable screening was performed using a stepwise approach. Prediction accuracy was assessed using receiver operating characteristic (ROC) analyses on the explanatory variables identified as potential risk factors for Salmonella contamination.

Results: Salmonella risk classification yielded 43 flocks as no risk, 16 as medium-risk, and 7 as high-risk of contamination. Screening for explanatory variables resulted in the identification of median Salmonella level in paw swabs and proportion of Salmonella-positive samples from trailer swabs as potential risk factors for the probability of high-risk Salmonella contamination in ground turkey samples (P = 0.0042 and P = 0.0536, respectively). A ROC curve analysis using leave-one-out cross validation was used to assess predictive accuracy and yielded an estimated area under the curve of 67.8% (95% confidence interval: 48.9, 86.7). The optimal operating ROC point resulted in an 85% sensitivity and 64% specificity for detection of high-risk Salmonella contamination, corresponding to diagnostic thresholds of 25% of trailer swab samples testing positive and a median level of −0.3 log CFU/mL in paw swab samples.

Conclusion: Results from this study indicate that the median Salmonella level in paw swabs and the proportion of Salmonella-positive samples from trailer swabs may serve as diagnostic predictors for high-risk Salmonella contamination in ground turkey. Moreover, by setting an optimal threshold of 25% of positive trailer swabs and −0.3 log CFU/mL of median paw swabs, the accuracy of predictions shows 85% sensitivity and 64% specificity. Although not causative by nature, these insights can provide direction to the turkey industry in identifying an effective sampling plan for early identification of Salmonella contamination in ground turkey and the deployment of effective intervention strategies.

Funding Source: This research was supported by the intramural research program of the U.S. Department of Agriculture, National Institute of Food and Agriculture, Food Safety and Defense Program (A1332).

Keywords: ground turkey, prediction, risk, Salmonella, supply chain

167 MICROBIAL CONTAMINATION IN MEAT PROCESSING FACILITY CLEANING TOOLS

J. Dunn^1,*, B. O. Maloney¹, I. G. Gafanha¹, A. D. Belk¹, ¹Animal Science, Auburn University, Auburn, Alabama, United States *jkd0042@auburn.edu

Objectives: In meat processing facilities, cleaning equipment and tools are relied upon daily to remove waste and break apart microbial biofilms to facilitate effective sanitation. However, it is possible that these tools could harbor and spread bacteria onto the surfaces being cleaned instead. As this topic is understudied in meat and food science applications, the overall objective of this research was to identify the microbial contamination level and overall microbiome of cleaning tools to determine whether they could have an impact on food safety. Specifically, this study sought to (1) determine the microbial load and microbiome of cleaning tools, (2) determine the specific factors that have an impact on the microbiome of the cleaning tools, and (3) determine the likelihood of microbial transfer between cleaning tools and contact surfaces they were used on. The hypothesis was that the microbial contamination level of certain cleaning tools such as scouring pads will be high, and as a result these may transfer microbes to surfaces.

Materials and Methods: To investigate these objectives, a longitudinal factorial experiment was designed to collect samples from cleaning tools including scouring pads, water in cleaning tool storage buckets, hoses, and contact surfaces weekly using pre-moistened sponges and sterile swabs for a 3-wk period. Each week, 13 samples were taken from various locations throughout the plant, totalling 36 samples. These samples were analyzed for microbial counts of Escherichia coli, Staphylococcus aureus, Salmonella spp., and Aerobic Plate Counts (APC) as well as the microbiome. The collection timepoints were the mornings after cleaning and sanitation before any products were introduced to the facilities. Microbial counts were measured after serial dilution using selective/differential media. Then, DNA was then extracted using a commercial kit and sequenced for the 16S rRNA gene. These data were analyzed using R software and QIIME2.

Results: There was a significant interaction between sample type and week for APC, indicating that different tools were differentially favorable environments for growth. The APC were highest (P < 0.05) in the scouring pads used at the processing facilities, nearing a point that could indicate unsanitary conditions for food. The scouring pad sample’s APC log increased (P < 0.05) as the weeks progressed. There was little growth of E. coli, Salmonella, and S. aureus in most samples. Trace amounts of E.coli were found only in the scouring pads and on one of the contact surfaces tested. The only Salmonella detected was found in the water of the cleaning tool storage buckets, though it is unclear how it contaminated this location without being identified in scouring pads. Minimal S. aureus was found within most of the samples, but it was highest in the water buckets and contact surfaces. The microbiome data will then be further explored with 16S rRNA sequencing to further assess any risks to food safety.

Conclusion: Cleaning tools in meat processing facilities can harbor a high level of microbial contamination, which has the potential to impact food safety and quality. E. coli, Salmonella, S. aureus were all identified in the samples tested. The high APC found in the scouring pads has an especially high risk for food safety, because they could directly contaminate contact surfaces during cleaning. Moreover, the increase in scouring pad contamination over time demonstrates the importance of replacing cleaning tools regularly.

Funding Source: This research was funded by Auburn University.

Keywords: cleaning and sanitation, microbiology, microbiome, safety, scouring pads

168 SAFETY TRAINING NEEDS ASSESSMENT FOR THE MEAT CUTTING AND PROCESSING INDUSTRY

A. Jayadas¹, M. Pfeiffer^2,*, T. Chandrasekera¹, ¹Design and Merchandising, ²Animal and Food Science, Oklahoma State University, Stillwater, Oklahoma, United States *aditya.jayadas@gmail.com

Objectives: This study aims to identify and prioritize specific safety training needs within the meat cutting and processing industry. It focuses on developing interventions that could potentially reduce workplace injuries, particularly addressing the high incidence rate and inherent risks involved in the industry.

Materials and Methods: The research employed a targeted needs assessment across 10 facilities, incorporating a diverse participant group of 10 individuals (age: 38.40 ± 10.36 y; 2 females and 8 males; experience ranging from 6 mo to 30 y). The methodology combined quantitative and qualitative approaches, utilizing surveys and semi-structured interviews to collect data. Descriptive statistics were applied to analyze the information gathered, focusing on current training practices and identifying critical gaps in safety training.

Results: The majority of facilities (80%) utilized live demonstrations or videos for safety training, with only 30% using additional written materials. Training sessions typically lasted between 1 to 2 h, occurring quarterly to annually. Key areas identified for improvement included knife safety, comprehension of safety rules, and emergency response protocols. Despite recognizing the importance of safety training, there was considerable resistance to adopting virtual reality-based methods. Emphasis was also placed on training for environmental adaptations, such as working in cold conditions, over other areas like respirator use.

Conclusion: The study underscores the urgent need for a strategic revamp of safety training programs in the meat processing industry. Future training should be more frequent, comprehensive, and specifically tailored to address the most significant risks, such as knife handling. The industry’s hesitance towards VR-based training suggests a preference for more traditional, hands-on instructional methods. Further research is recommended to explore the relationship between training intensity, frequency, and the actual reduction in workplace incidents, which could lead to the development of more effective and economically viable training solutions, thereby enhancing overall safety outcomes in the sector.

Funding Source: College of Education and Human Sciences, Oklahoma State University

Keywords: meat cutting and processing, safety training, virtual reality, working conditions

169 EFFECT OF TOPICAL TREATMENT OF LIQUID SMOKE ON THE OUTGROWTH OF SLIME-FORMING LEUCONOSTOC MESENTEROIDES IN FRANKFURTERS

S. Potkamp^1,*, E. Heintz¹, S. Kumar², ¹Food Protection & Preservation, Kerry, Wageningen, Netherlands, ²Food Protection & Preservation, Kerry, Beloit, Wisconsin, United States *simone.potkamp@kerry.com

Objectives: Determine effectiveness of topical treatment of frankfurters using clean label smoke extract to reduce outgrowth of Leuconostoc mesenteroides, and thereby slime formation, and to check the visual defects during storage.

Materials and Methods: Slime-forming Leuconostoc mesenteroides strains were isolated from commercial frankfurter samples. Store-bought pork frankfurters were dip inoculated in an inoculum containing a cocktail of two of these L. mesenteroides strains, targeting 2–3 log CFU/g. Liquid smoke solutions of Cloud SC100, 3% and 6%, were prepared in sterile demineralized water, of which 1 mL was added to each bag containing 1 sausage, resulting in 0.15% and 0.3% of SC100 on weight-basis. A control without preservatives was included, where 1 mL of sterile demineralized water was added to the sausage. The bags were vacuum sealed and stored at 4°C for 22 d. At each time point, samples were homogenized and plated on MRS agar. Differences between treatments were analyzed using one-way ANOVA (P < 0.05).

Results: Control samples without preservatives reached a spoilage threshold of 7 log(CFU/g) after 9 d. Topical treatment using 0.15% and 0.3% Cloud SC100 significantly (P < 0.05) increased the shelf life of the frankfurters, reaching 7 log(CFU/g) after 15 and 18 d, respectively (Table 1). Samples with preservatives remain at inoculation level for 4 and 8 d for 0.15% and 0.3% respectively. No visual defects were observed during storage; product color remained stable for all treatments.

Conclusion: The results of this study demonstrate the possibility to reduce slime formation in frankfurters using a smoke extract, Cloud SC100.

Keywords: Leuconostoc, preservation, slime formation, smoke, organic acids, frankfurters, spoilage

170 NATIONWIDE SURVEILLANCE OF SALMONELLA IN SOW LYMPH NODES AND TONSILS

S. Zhang^1,*, R. L. Jimenez², M. M. Brashears², M. X. Sanchez-Plata², S. E. Gragg¹, ¹Animal and Dairy Sciences, University of Wisconsin-Madison, Madison, Wisconsin, United States, ²Animal and Food Sciences, Texas Tech University, Lubbock, Texas, United States *sgragg@wisc.edu

Objectives: Salmonella contamination in the lymph nodes (LN) of sows may lead to contamination of carcasses, sausages, and other pork products. Thus, determining prevalence of Salmonella in tonsils and LN from processing facilities across the United States can offer valuable insights into the risk that these contaminated tissues pose to public health.

Materials and Methods: Lymph nodes and tonsils from sows (N = 610) were collected from 3 commercial pork abattoirs across the U.S. during the 2024 winter season. From each carcass, mesenteric, subiliac, superficial inguinal, pre-scapular, axillary, and tracheobronchial LN, as well as tonsils, were collected. After trimming and weighing, the samples were boiled, pulverized, and enriched with BAX MP media. Using the BAX System, Salmonella was detected after 24 h of incubation at 42°C.

Results: The overall Salmonella prevalence was 10.33%. For each sample type, the Salmonella prevalence was 37% in tonsils, 17% in mesenteric LN, 0.10% in superficial inguinal LN, 0.04% in pre-scapular LN, and 0.03% in tracheobronchial LN. Salmonella was not detected in subiliac LN and axillary LN.

Conclusion: The prevalence of Salmonella was greatest in tonsils and mesenteric LN, neither of which are incorporated into ground product and thus pose more of a risk for cross-contamination during carcass processing. The remaining LN are associated with the carcass and may be incorporated into ground product, which provides a direct route for Salmonella contamination. These findings provide information for commercial pork abattoirs to assess and manage risks associated with Salmonella contamination.

Funding Source: Foundation for Meat and Poultry Research and Education

Keywords: lymph nodes, prevalence, Salmonella, sow, tonsils

171 EFFECT OF LOW AND HIGH CARBONYL SMOKE FRACTIONS ON SPOILAGE CONTROL IN MEAT

S. Wason^1,*, N. Hall¹, J. Saha¹, S. Kumar¹, ¹Food Preservation & Protection, Kerry, Beloit, Wisconsin, United States *surabhiwason25@gmail.com

Objectives: Carbonyl fractions, generated from pyrolysis of wood, enhance flavor and color and antimicrobial efficacy of smoke systems. The present study assesses the efficacy of low carbonyl (LC) and high carbonyl (HC) smoke systems against spoilage and pathogenic micro-organisms.

Materials and Methods: Samples of liquid smokes with varying carbonyl concentrations (Cloud S-C100, Cloud S-6, Cloud S-9, Cloud 320) were prepared at varying concentrations (0–4%) in selective broth. Samples were prepared at pH 6.0. Samples were aliquoted into 100-well plates then inoculated with spoilage bacteria such as Lactobacillus sakei, Lactobacillus planatarum, Leuconostoc mesenteroides, Lactobacillus cremoris, Pediococcus pentosaceus, Enterococcus faecalis, and pathogenic bacteria such as Listeria monocytogenes, Salmonella Typhimurium, Escherichia coli, Bacillus cereus, and Staphylococcus aureus (∼6 log CFU/g). The plates were placed in the Bioscreen-C at 30°C to generate growth curves. Modified Gompertz equation was used to determine the maximum growth rate (μmax; h^–1) which was further used to determine the minimum inhibitory concentration (MIC). Data was analyzed using one-way ANOVA (P < 0.05).

Results: HC systems (Cloud 320 and Cloud S-C100) were more effective against pathogenic and spoilage bacteria as compared to LC. At 0.25% and 1%, Cloud S-C100 and Cloud 320 showed no growth of all the microorganisms tested. For L. sakei, MIC of S-C100, Cloud 320, Cloud S-9, were 0.25%, 0.50%, and 2.0%, respectively. Contrary to HC systems, Cloud S-6 (LC concentration) had a significantly greater MIC of 2.5% against L. sakei whereas for S. Typhimurium, at 1.0% it notably reduced the growth rate (2.9 h-1 vs. blank at 6.5 h-1; P < 0.05).

Conclusion: Smoke systems with specific carbonyl concentration could be selected to provide desired product characteristics in terms of spoilage control.

Keywords: None

172 SURVEY OF SALMONELLA DISTRIBUTION IN BOVINE BODY SYSTEMS

T. Loeffler^1,*, T. R. Brown², P. R. Broadway³, K. E. Hales⁴, J. E. Wells⁵, L. W. Lucherk¹, T. E. Lawrence¹, ¹Animal Science, West Texas A&M University, Canyon, Texas, United States, ²Global Food Safety Research & Scientific Services Leader, Cargill Inc., Wichita, Kansas, United States, ³LIRU, USDA, ⁴Animal Science, Texas Tech University, Lubbock, Texas, United States, ⁵Meat Safety and Quality, USDA, Clay Center, Nebraska, United States *tloeffler@wtamu.edu

Objectives: Limited research has been conducted to identify tissue specific areas of Salmonella colonization and contamination. Our objective was to survey the distribution of Salmonella within bovine body systems.

Materials and Methods: An observational experimental design was used in which beef cattle from different feedyards (n = 22) were sampled throughout the harvest process (hide swab, rectal contents, blood, cheek meat, brisket swab pre-evisceration wash, brisket swab post-evisceration wash, ileum, kidney, liver, spleen, rib cage swab pre-final wash, rib cage swab post-final wash, subiliac and subscapular lymph nodes, and bone marrow). Environmental samples were collected from equipment and employees for background testing as well. Samples were homogenized, spiral plated for enumeration, enriched, isolated, and PCR confirmed prior to antimicrobial resistance profiling via Sensititre.

Results: Results yielded a 63.6% Salmonella prevalence in fecal samples and a 54.5% prevalence for hide swabs. Of the 22 steers tested, 45.5% resulted in a positive Salmonella sample from their ileum, and 22.7% yielded Salmonella in their subiliac lymph nodes. Samples taken from the spleen resulted in 18.2% prevalence, whereas samples from blood, liver, subscapular lymph nodes, and kidney each yielded a 4.5% prevalence. No positive samples were observed in cheek meat, brisket swab pre-evisceration wash, brisket swab post-evisceration wash, rib cage swab pre-final wash, rib cage swab post-final wash, bone marrow, or any environmental swabs. Salmonella mean concentrations were greatest in SLN samples at 6.2 Log₁₀/g, followed by fecal samples at 3.0 Log₁₀/g. Samples collected from liver, kidney, and spleen had a mean concentration of 0.3 Log₁₀/g. Antimicrobial resistance was tested across Salmonella isolates; no resistance was detected for amoxicillin-clavulanic acid, cefoxitin, ceftriaxone, chloramphenicol, ciprofloxacin, gentamicin, meropenem, nalidixic acid, sulfasalazine, or trimethoprim sulfamethoxazole. Isolates had resistance (1.25%) to ampicillin, tetracycline (3.13%), streptomycin (3.75%), and azithromycin (11.88%).

Figure 1.

Graph displays all positive Salmonella samples. Cheek tissue samples and surface swabs (pre-brisket, post-brisket, brisket saw, pre-rib cage, post-rib cage, and bone marrow) did not yield positive samples.

Conclusion: From 2012 to 2019, Salmonella in beef was estimated to be linked to 1,103 illnesses, 254 hospitalizations, and 2 deaths. Producers and harvest facilities have implemented pre and post-harvest intervention methods to reduce Salmonella contamination. With lack of contamination of carcass swabs (brisket swab pre-evisceration wash, brisket swab post-evisceration wash, rib cage swab pre-final wash, rib cage swab post-final wash) our findings indicate that sanitary dressing procedures and post-harvest interventions are effective in the reduction of Salmonella contamination. Within positive Salmonella samples, no multi-drug resistance was detected and minimal resistance was detected for critically important antibiotics (with the exception of azithromycin). Previous research has demonstrated that ground beef has been a cause of Salmonella outbreaks. As literature and results suggest, this is due in part to lymph nodes that are mixed into ground beef, causing possible contamination with Salmonella. However, this is not the only concern anymore. As these results suggest, Salmonella may be detected in multiple tissues.

Funding Source: This project was generously funded by Cargill Inc, Wichita, KS.

Keywords: antimicrobial resistance, tissue

173 IMPACT OF VINEGAR AND NATURAL FLAVOR ON SHELF-LIFE EXTENSION OF FRESH POULTRY AND SENSORY PERCEPTION

S. Wason^1,*, J. Kataria¹, J. Saha¹, R. Weyker², P. Ludtke², K. Rumbaugh¹, S. Kumar¹, ¹Food Preservation & Protection, ²Meat Applications, Kerry, Beloit, Wisconsin, United States *surabhiwason25@gmail.com

Objectives: Natural flavor and weak organic acids-based preservation system provide clean label solutions for meat shelf-life and food safety extension. The purpose of the present study is to evaluate the efficacy of dried vinegar and natural flavor products (NF1, NF2, NF3), individually and in combination with a vinegar-based plant extract for control of spoilage microorganisms in ground chicken.

Materials and Methods: Ground chicken was treated with natural flavor (1.5% NF1, 1.5% NF2, and 1.0% NF3) alone, and in combination with 0.75% dried vinegar. Treated samples were packed under aerobic atmosphere and stored at 4°C for up to 30 d. On each sampling day, duplicate samples were processed to enumerate for lactic acid bacteria (LAB) and aerobic plate count (APC). Spoilage threshold was considered as 6 log CFU/g. Sensory analysis was conducted on second day after treatment. Differences among the treatments were determined using one-way ANOVA using JMP Pro version 16.1.0 (SAS Institute Inc., NC, US), with significance set at P ≤ 0.05.

Results: NF1, NF2, and NF3 alone controlled the APC and LAB growth below 6 log CFU/g until day ∼10 in fresh poultry at 4°C. Combination of NF1 (1.5%), NF2 (1.5%), or NF3 (1%) with dried vinegar (0.75%) exhibited a synergistic effect on ground chicken, significantly enhancing the shelf life to 20, 20, and 17 d, respectively while dried vinegar alone provided 13 to 15 d of shelf life. For LAB growth, dried vinegar combined with NF1 (1.5%), NF2 (1.5%), and NF3 (1.0%) showed a significant increase (P < 0.05) in shelf-life of fresh poultry, i.e., 30, >30, and 27 d, respectively, in comparison to control (no preservative) which reached spoilage threshold for LAB after 7 d. In terms of quality characteristics, the moisture content%, salt%, fat%, and pH of the treated samples were in the range of 73.3–74.7%, 0.2–0.3%, 5.8–6.5%, and 6.3–6.6%, respectively, and were not significantly different from the control (74.8%, 0.29%, 6.2%, and 6.5, respectively). Treatment NF3 had acceptable sensory profile with mild flavor and color being characterized as desired attributes by the panelists.

Conclusion: Combination of dried vinegar and natural flavor-based preservation systems offers promising clean label solution for shelf-life extension of ground poultry while meeting consumer expectations for safer food products.

Keywords: None

174 EQUIPMENT AND HAND SANITATION AUDIT OF CANADIAN BEEF ABATTOIRS

Z. Platter^1,*, T. Brown², L. Lucherk¹, T. Tennant¹, T. Lawrence¹, ¹Animal Science, West Texas A&M University, Canyon, Texas, United States, ²Global Food Safety, Cargill Inc., Wichita, Kansas, United States *zplatter@wtamu.edu

Objectives: Our objective was to audit equipment and hand sanitation methods during harvest of Canadian beef cattle.

Materials and Methods: Data were collected at two beef processors during August 2022 and February 2023. At each processing facility, biased and unbiased audits were conducted during each shift. For each audit, a list of critical food safety jobs were randomly divided amongst investigators. Jobs included Pre-Sticker, Sticker, Belly Ripper, Legger, Butter, Pattern Trimmer, Midline Opener, Flanker, Brisket Saw, Rim-over, Bung Dropper, Clear Weasand, Head Dropper, Head Transfer, Hock Cutter, Hock Sucker, Low-backer, Rumper, Weasand Rodder, Pre-Gutter, and Gutter. During biased audits, an auditor would stand near the worker performing the critical job and observe equipment and hand sanitation practices for 10 animals. Unbiased audit data were collected from a camera room whereby auditors remotely observed workers performing the same task on 10 animals via camera. Sanitation practices audited were handwashing frequency and frequency and duration of equipment and/or hook sanitation. Other observations included sanitation after knife sharpening, switching knives between carcasses, type and number of knives and/or hook, and any cross-contamination observed during the job task.

Results: Employees washed their hands between carcasses for 88% of biased observations and 84% of unbiased observations. Sanitation of equipment was accomplished with hot water (mean = 85°C) spray or immersion. Brisket saws were inserted into sanitizing hot water spray during 91% of observations for 1.4 ± 0.03 s. Frequency of sanitation and duration of immersion varied: Rotating power knives were sanitized during 100% of observations for 1.1 ± 0.02 s, pick hooks were sanitized during 79% of observations for 1.9 ± 0.1 s, node hooks were sanitized during 86% of observations for 2.2 ± 0.06 s, pneumatic de-hiders were sanitized during 98% of observations for 3.5 ± 0.08 s, leg clippers were sanitized during 87% of observations for a 4.9 ± 0.22 s, weasand rods were sanitized during 100% of observations for 9.4 ± 0.13 s, skinning knives were sanitized during 99% of observations for 9.6 ± 0.05 s, and straight knives were sanitized during 99.7% of observations for 9.8 ± 0.04 s. For job tasks with 2 knives, employees switched knives between carcasses for 96% of biased observations and 98% of unbiased observations. Knife sharpening/sanitation order errors were observed 1% of the time during biased observations and 2% during unbiased observations.

Figure 1.

Mean ± SEM immersion duration (s) of beer abattoir equipment into sanitizing hot water.

Conclusion: These data indicate that most equipment is being immersed in sanitizing hot water; however, immersion duration times vary widely based on individual equipment and task being performed. Companion data will determine duration of immersion required to reach sanitation temperature for each piece of equipment observed in this audit. Furthermore, these data suggest opportunity for improved sanitation procedures, particularly when equipment becomes contaminated.

Funding Source: This project was generously funded by Cargill inc., Wichita, Kansas.

Keywords: beef, food safety, sanitation, survey

175 EVALUATING POTASSIUM VINEGAR SYSTEMS AND VINEGAR FERMENTATE BLEND FOR SPOILAGE CONTROL AND SENSORY PERCEPTION IN FRESH CHICKEN TENDERS

S. Wason^1,*, J. Kataria¹, K. Rumbaugh¹, J. Saha¹, R. Weyker², P. Ludtke², S. Kumar¹, ¹Food Preservation & Protection, ²Meat Applications, Kerry, Beloit, Wisconsin, United States *surabhiwason25@gmail.com

Objectives: Traditionally, vinegar has been used as a marinade solution due to its ability to impart improved flavor and tenderness in poultry. Understanding the antimicrobial impact of vinegar systems can help processors extend shelf life of fresh poultry. The objective is to validate the antimicrobial effect of liquid vinegar systems; sodium (IsoAge 325L), vinegar fermentate blend Nourishield 2000L as marinades for controlling growth of spoilage microorganisms in marinated chicken tenderloins.

Materials and Methods: Fresh chicken tenders were treated with liquid vinegar, IsoAge 325L at 1.0 and 1.5% concentration alone and in combination with peptide, i.e., Nourishield 2000L at 2.2 and 2.7%. Samples were subjected to vacuum tumbling-immersion marination in chilled water, salt, and preservative at 8–10 rpm for 30 min at 4°C. Brine solution (without preservative) served as control. Treated samples (∼100 g) were vacuum-packed, stored at 4°C for up to 30 d. On each sampling day, duplicate samples were enumerated for lactic acid bacteria (LAB) and aerobic plate count (APC). Spoilage threshold was set at ∼6 log CFU/g. Sensory analysis was conducted on second day after treatment. Differences among the treatments were determined using one-way ANOVA at P < 0.05. Statistical analysis was performed in JMP Pro version 16.1.0 (SAS Institute Inc., NC, US), with significance set at P < 0.05. Means of each treatment group were compared by Tukey-Kramer adjustment (Tukey’s Honestly Significant Difference test) at 5% significance level.

Results: IsoAge 325 L at 1.5% were effective in controlling the spoilage with APC and LAB counts below 6 log CFU/g until 21 d while the control reached spoilage by day 7 (Table 1). IsoAge 325 L also significantly delayed growth of LAB (P < 0.05) until 17 d surpassing control (brine solution), which spoiled by day 7 (P < 0.05). The addition of peptide to vinegar significantly (P < 0.05) enhanced the shelf life of marinated poultry to more than 28 d. Nourishield 2000L at 2.2–2.7% exhibited superior antimicrobial efficacy in extending the shelf life of chicken tenders as compared to IsoAge 325L at 1.0–1.5% and control. Overall, all treatments had acceptable sensory profiles in terms of acetic, sour, bitter, metallic/ canned and oxidized off-flavor. Specifically, IsoAge 325L were acceptable by more than 75% of panelists.

Conclusion: Sodium/potassium/lemon buffered vinegar systems and vinegar fermentate blend can significantly extend the shelf-life of marinated poultry, providing processors with means to improve microbial stability and poultry meat quality with minimal changes to its sensory quality.

Keywords: None

176 EVALUATION OF CLOUD 320 AND CLOUD S-C100 FOR SALMONELLA INTERVENTIONS IN FRESH POULTRY

S. Wason^1,*, R. Furbeck¹, K. Rumbaugh¹, J. Saha¹, S. Kumar¹, ¹Food Preservation & Protection, Kerry, Beloit, Wisconsin, United States *surabhiwason25@gmail.com

Objectives: The objective of this study is to assess the efficacy of Cloud 320 and Cloud S-C100 for the control of Salmonella in fresh chicken application.

Materials and Methods: Skinless chicken breast, weighing on average 100 ± 3 g, were used for the study. The samples were spot inoculated with a two-strain cocktail of Salmonella Typhimurium and Salmonella Enteritidis at the 1 mL/100 ± 3 g to achieve target inoculation level of 2–3 log CFU/g. The inoculum was then spread using a sterile L spreader and rested for one hour in biosafety cabinet for attachment. As per Table 1, the samples were then treated with Cloud smokes by spray application using airbrush and ground after 30 min. Treated ground chicken samples (∼50 g) were air flushed with 70% nitrogen and 30% carbon dioxide and stored at 4°C for up to 30 d. At each sampling point, duplicate samples were homogenized and plated onto XLT4 agar selecting for Salmonella, and TSA for total aerobic plate count. Treatment effect was evaluated with one-way ANOVA in SAS JMP 17. Significance in this study is set at P ≤ 0.05.

Results: All inoculated samples reached the target inoculum levels of 2–3 log CFU/g. The smoke solutions, Cloud 320 and Cloud S-C100, showed cidal effects on Salmonella in ground chicken. On Day 0, 1.5% Cloud 320 significantly (P ≤ 0.05) lowered the Salmonella levels from 2.80 log CFU/g in untreated samples to 1.85 log CFU/g, whereas 2.0% Cloud 320 and 0.3–1.2% Cloud S-C100 provided were below the detection limit (0.7 log CFU/g) for Salmonella. The carnosic acid had no significant impact in controlling Salmonella in fresh poultry. The antimicrobial efficacy of Cloud S-C100 was significantly greater (P ≤ 0.05) than Cloud 320.

Conclusion: The spray application of Cloud 320 and Cloud S-C100 provide effective intervention strategy and clean label solution for Salmonella control in ground poultry applications.

Keywords: None

177 QUANTIFICATION OF SALMONELLA IN SWINE LAIRAGE PENS

A. Abrego^1,*, W. Wu², R. L. Jimenez³, G. Houston⁴, M. Miller⁴, D. M. Brichta-Harhay², M. M. Brashears³, S. E. Gragg¹, J. W. Schmidt², ¹Animal and Dairy Sciences, University of Wisconsin-Madison, Madison, Wisconsin, United States, ²Meat Safety and Quality Research Unit, US Meat Animal Research Center, USDA-ARS, Clay Center, Nebraska, United States, ³Animal and Food Sciences, Texas Tech University, Lubbock, Texas, United States, ⁴Technical Services Department, Triumph Foods, Saint Joseph, Missouri, United States *sgragg@wisc.edu

Objectives: The commensal state of Salmonella in pigs is often attributed to stressful events, including time in lairage pens. Quantification of Salmonella levels in lairage assist the design and implementation of Salmonella mitigations. The objective of this study was to compare direct plating, BAX, and MPN quantification methods for monitoring Salmonella levels in ropes masticated by swine, pen floor MicroTally swabs, and pen floor boot sock swabs obtained from swine lairage pens.

Materials and Methods: Each of 15 lairage pens at a commercial swine processing establishment were sampled. A 24-inch length cotton rope was hung at swine shoulder height for 30 min in each populated pen. Following pen depopulation, ½ of a Fremonta Microtally swab pre-wetted with Buffered Peptone Water (BPW) was placed on a clean mop head and dragged in a ‘W’ pattern (approximately 10–15 feet) at the front of the pen. This process was repeated in the middle and back of each pen for a total of 3 Microtally samples per pen. Then pen was walked in an hourglass pattern wearing Hardy Diagnostics Envirobooties over clean plastic bootcovers. Each boot sock was placed in a separate bag and processed as a separate sample. Ropes and boot socks were suspended in BPW. MicroTally swabs were suspended in BAX-MP. For direct plating, 50 uL was spiral plated on to Xylose Lysine Deoxycholate agar. For MPN, appropriate dilutions in triplicate were prepared in BPW and enriched. Salmonella in each well was detected using the BAX System Real-Time PCR Salmonella Assay. For BAX quantification of ropes an aliquot of suspension was enriched with BAX-MP. Boot sock swab-BAX-MP suspension was enriched for BAX quantification. BAX quantification was not performed with MicroTally swabs. BAX Salmonella Ct values were used with the Hygiena Quant Calculator to produce quantitative results. For ropes, the lower limits quantification (LOQ) for BAX, MPN, and direct plating were 2.48 log CFU/sample, 1.52 log MPN/sample, and 3.78 log CFU/sample, respectively. For boot sock swabs, the lower LOQ of BAX, MPN, and direct plating were 2.00 log CFU/sample, 1.04 log MPN/sample, and 3.30 log CFU/sample, respectively. For MicroTally swabs, the lower LOQ of MPN and direct plating were 1.34 log MPN/sample and 3.60 log CFU/sample, respectively. Mean values in Table 1 only consider results ≥ than the lower LOQ.

Results: The BAX method identified the most rope samples above the LOQ, with 9 samples harboring a mean of 5.68 log CFU/sample. The MPN method detected the most boot sock and MicroTally samples above the LOQ, with 21 and 29 samples harboring means of 2.28 and 2.5 log MPN/sample, respectively. The direct plating identified the fewest number of samples above the LOQ.

Conclusion: This study demonstrates that Salmonella quantification from swine lairage samples varies based on sample matrix and method LOQ. MPN is associated with the lowest LOQ; however, the BAX quantified more rope samples than MPN. Conversely, the highest LOQ is associated with direct plating, which quantified the fewest number of samples. MPN quantified Salmonella from more boot sock samples than BAX, suggesting that the lower Salmonella concentrations on lairage boot socks are more readily detected by MPN, which has a lower LOQ than BAX. These data suggest that the appropriate quantification method may vary depending on Salmonella concentration and sample characteristics.

Funding Source: Foundation for Meat and Poultry Research and Education, Agricultural Research Service National Program 108—Food Safety.

Keywords: lairage, pre-harvest, quantification, Salmonella, swine

178 ANTIMICROBIAL EFFICACY OF VINEGAR-BASED SOLUTIONS AGAINST LISTERIA MONOCYTOGENES

N. Hall^1,*, J. Saha¹, R. Furbeck¹, E. Heintz², S. Kumar¹, ¹Food Protection and Preservation, Kerry, Beloit, Wisconsin, United States, ²Food Protection and Preservation, Kerry, Tiel, Netherlands *nicolette.hall@kerry.com

Objectives: Clean-label antimicrobials, such as buffered vinegar and organic acids, offer advantages including flavor enhancement, extended shelf life, and improved food safety. This study evaluates the minimum inhibitory concentrations (MIC) of several vinegar-based solutions, including liquid buffered vinegars (IsoAge 210L; BV1; IsoAge 240L; BV2), lemon buffered vinegar system (Nourishield 5000L; BV3), and a dry buffered vinegar (IsoAge DV100; BV4), against Listeria monocytogenes.

Materials and Methods: BV1, BV2, BV3, and BV4 were tested at concentrations ranging from 0% to 2% in Brain Heart Infusion broth at pH levels of 5.8 and 6.0. After inoculation with a mixture of L. monocytogenes serotypes, optical density at 600 nm was measured to monitor growth and incubated at 30°C. Each BV sample was tested in duplicate at every concentration level. Growth rates were determined using the modified Gompertz equation, with MIC defined as the minimum concentration inhibiting bacterial growth using this method. Treatment effect was evaluated with one-way ANOVA in SAS JMP 17. Significance in this study is set at P ≤ 0.05.

Results: All tested solutions inhibited L. monocytogenes similarly across pH values, except for BV3 showing significant variation (P < 0.05). The lowest MIC values were observed for BV4 (1.7% at pH 5.8 and 1.8% at pH 6.0), followed by BV1 and BV2, and the highest for BV3 (3.3% and 4.3% at pH 5.8 and 6.0, respectively).

Conclusion: This research demonstrates the efficacy of vinegar-based systems as antimicrobial agents against L. monocytogenes, suggesting their potential as natural food preservatives.

Keywords: antimicrobials, clean label, in vitro, Listeria monocytogenes, vinegar

179 USE OF CLEAN LABEL ANTIMICROBIAL AND NATURAL FLAVOR TO CONTROL LACTIC ACID BACTERIA AND SALMONELLA IN RAW PET FOOD

N. Hall^1,*, J. Kataria¹, J. Saha¹, S. Kumar¹, ¹Food Protection and Preservation, Kerry, Beloit, Wisconsin, United States *nicolette.hall@kerry.com

Objectives: High-moisture raw pet food, due its higher water activity (a_w), poses spoilage and food safety risks, especially Salmonella, creating the need for sustainable clean-label solutions. The current study assesses the in vitro efficacy of buffered vinegar and Lactococcus lactis ferment (Everwild 20L) in combination with smoke system (EverWild S100) against specific spoilage (lactic acid Bacteria [LAB] and mold) and pathogenic microorganisms (Salmonella spp.) isolated from semi-moist pet food.

Materials and Methods: Solutions were prepared with 2.5% Everwild 20L and varying concentrations of EverWild S100 (0-0.45%) in Brain Heart Infusion (for Salmonella spp.) and deMan Rogosa and Sharpe (for LAB strains), and Potato Dextrose Broth (PDA) with 0.125% (w/v) agar (for mold strains). The control without preservative of each media was prepared in the same manner. Samples, adjusted to pH 6.0, were aliquoted into 100-well plates. Wells were inoculated with LAB (Lactobacillus cellobiosus, L. sakei, L. curvatus, Enterococcus faecium, E. faecalis), Salmonella Typhimurium, S. Enteritidis, S. Heidelberg, S. Mbandaka, and S. Agona, or mold (Aspergillus oryzae, Penicillium roqueforti, and Eurotium herbariorum) and incubated at 30°C using Bioscreen-C Pro. Growth curves (600 nm) were fitted using modified Gompertz equation to determine the maximum growth rate (μmax; h⁻¹) and lag time (h). Differences among the treatments were determined using one-way ANOVA at P < 0.05.

Results: Everwild 20L in combination with a minimum concentration of smoke system of 0.3% exhibited bactericidal effect and inhibited both LAB and Salmonella serotypes (Table 1). Without EverWild S100, 2.5% of Everwild 20L alone, significantly (P < 0.05) reduced growth rate and increased lag time of all the Salmonella serotypes (0.81h⁻¹;0.32h) compared to the control (16.6h⁻¹;0.1h). For LAB, similar inhibition pattern was observed; however, only L. curvatus growth was inhibited by 2.5% of Everwild 20L. For mold inhibition, Everwild 20L in combination with EverWild S100 exhibited a synergistic effect. Everwild 20L with 0.45% EverWild S100 significantly (P < 0.05) reduced growth rate and increased lag time of A. oryzae (1.86h⁻¹; 4.79h) compared to the control (3.99h⁻¹;0.67h). A similar inhibition pattern was observed for P. roqueforti and E. herbarorium.

Conclusion: Synergistic blend of buffered vinegar/peptide ferment and smoke system could potentially function as an effective clean-label antimicrobial and flavor system for raw, high-moisture pet food applications.

Keywords: antimicrobials, in vitro, pet, Salmonella, spoilage

180 APPLICATION OF EUGENOL NANOEMULSION IN CONTROLLING SALMONELLA ENTERITIDIS ON POULTRY PRODUCTS

J. Allen^1*, B. Balasubramanian¹, S. A. Baskaran², Y. Luo³, A. Upadhyay¹, ¹Animal Science, University of Connecticut, Storrs, Connecticut, United States, ²Veterinary Public Health and Epidemiology, Tamil Nadu Veterinary and Animal Sciences University, Orathanadu, India, ³Nutritional Sciences, University of Connecticut, Storrs, Connecticut, United States *jodie.allen@uconn.edu

Objectives: This study investigated the efficacy of Eugenol oil (EG) in its nanoemulsion form (EGNE) as dip treatments in inactivating Salmonella Enteritidis (SE) on broiler chicken skin.

Materials and Methods: EGNE was prepared with Gum Arabic and lecithin (GAL) as emulsifiers using ultrasonication, a high energy method. Chicken skins were spot-inoculated with a 5-strain cocktail of SE (10⁷ CFU/sample), followed by dipping in sterile DI water (control) or water containing Peracetic acid (PAA) 0.02%, GAL 0.5%, EG, or EGNE at 0.3, 0.6, 1.25% for 15, 30, 240 or 480 min at 4°C. The efficacy of the highest dose-time combination of EGNE was tested in reducing SE on multiple skins (to mimic whole broiler carcasses chilled collectively in a chill tank at a poultry processing facility). Briefly, SE inoculated skins (10 samples per treatment) were collectively washed in a receptacle containing 400 mL sterile DI water (control), PAA 0.02%, GAL 0.5%, EGNE or EG 1.25% at 4°C for 480 min. Post treatment, the surviving SE on chicken skin and in wash water was enumerated. Moreover, SE population was enumerated in wash water, followed by enrichment if undetectable. All experiments had triplicate samples, repeated thrice, and analyzed using one-way ANOVA (P < 0.05).

Results: EGNE had a particle size of ∼82 nm, PDI of <0.3 and zeta-potential of ∼ −36.70 mV. In baseline (SE inoculated skin, not washed), ∼7.21 log CFU/sample SE were recovered. Washing with water or GAL did not reduce SE on skin (P > 0.05). All nanoemulsion concentrations were effective, as early as 15 min, in reducing SE by ∼0.81, 1.45, 1.74 log CFU/sample, respectively, as compared to control (P < 0.05). EGNE 1.25% was more effective than corresponding EG treatment at all timepoints and reduced SE by ∼3.26 log CFU/sample as compared to control by 480 min. No significant difference between EGNE 1.25% and PAA was observed at 15 or 30 min wash time (P > 0.05). However, at 240 and 480 min wash time, EGNE 1.25% was more effective than PAA and reduced SE by additional 1.5 log CFU (P < 0.05). For collective skin wash experiments, EGNE 1.25% reduced SE by ∼2.85 to 3.64 log CFU/sample as compared to control, GAL, PAA, and EG 1.25% (P < 0.05). For wash water (480 min), ∼4.88, 4.76, and 1.41 log CFU/mL SE was recovered in control, GAL, and PAA treatments respectively. EGNE and EG 1.25% inactivated SE population in wash water undetectable, and tested enrichment negative as compared to control (P < 0.05).

Conclusion: EGNE could potentially be used as a natural antimicrobial wash to reduce SE on poultry products.

Funding Source: USDA-NIFA-AFRI-A1332 program: Developing plant-based drinking water supplements for controlling Salmonella and Campylobacter jejuni in broiler chickens.

Keywords: chicken skin, emulsifiers, Eugenol, nanoemulsion, Salmonella

181 CLEAN LABEL SOLUTIONS TO CONTROL THE TOXICITY OF CLOSTRIDIUM BOTULINUM IN UNCURED TURKEY BREAST

T. Verma ^1,*, G. Mccoy ¹, B. Howard ¹, R. Ames ², R. Garza ², K. Glass ³, K. Schill ³, ¹Research and Development, ²Business Development, Corbion, Lenexa, Kansas, United States, ³Food Research Institute, University of Wisconsin, Madison, Wisconsin, United States *garrett.mccoy@corbion.com

Objectives: Clostridium botulinum is gram positive, sporeforming bacteria that grows under anaerobic conditions. During the sporulation process, C. botulinum produces a lethal neurotoxin. In vacuum-packaged meats, the lack of oxygen creates an ideal environment for the growth of C. botulinum. The anaerobic environment could potentially induce sporulation if the product is not properly handled, processed, or stored. Sodium nitrite has been used as a gold standard preservative for C. botulinum control in cured meats. However, clean label solutions are needed for uncured meat products. The objective of this study was to evaluate the efficacy of clean label antimicrobials (cultured sugar and vinegar) in comparison with sodium nitrite to delay C. botulinum toxicity in a model meat system.

Materials and Methods: Boneless, skinless turkey breasts were ground through a 3.175 mm (1/8") plate and formulated with 5 treatments (no antimicrobial, 100 ppm sodium nitrite with 250 ppm ascorbate, 3% (w/w) Verdad® Powder N20 (Cultured Sugar), 1.1% (w/w) Verdad® Powder N6 (Vinegar), and 2.5% (w/w) Verdad® Opti Powder N510 (Cultured Sugar and Vinegar). Raw batter of each treatment was inoculated with approximately 2.50 log CFU/g of a 10-strain cocktail of proteolytic and non-proteolytic C. botulinum spores (Types A, B, and E). The prepared samples (25 g) were portioned into 3 mil high barrier pouches (Oxygen transmission rate 50 to 70 cm³/m²) and vacuum packaged. The inoculated vacuum packaged meat samples were suspended on racks and submerged into a large water bath (75°C) for spore activation. After the internal temperature reached 73°C, packages were removed and chilled to ≤13°C in an ice-water bath, then transferred to a temperature-controlled incubator set at 7.2°C and 12.8°C for up to 20 wk. The initial spore population in the inoculated sample was determined in duplicate for each treatment using the 5-tube Most Probable Number method to enumerate C. botulinum. The standard mouse bioassay was performed to determine the earliest time to C. botulinum toxicity in each formulation. Trypsin was used to activate the toxin produced by non-proteolytic strains, whereas proteolytic strains has its own enzyme to activate the toxin. When mouse deaths occurred, samples were heated to 80°C for 20 min to neutralize toxin, additional pairs of mice were injected, and symptoms were observed to confirm the presence of botulinum toxin. Enumeration of the non-proteolytic strains at 7.2°C is unreliable; therefore, only samples stored at 12.8°C were plated for C. botulinum (differential Reinforced Clostridial agar; anaerobic incubation, 30°C, 48 h).

Results: The proximate values for all treatments were measured on day 0 and are shown in Table 1. The initial population of C. botulinum in all the treatments averaged 2.11 ± 0.48 log spores/g. The control samples without antimicrobials supported C. botulinum toxin production at 4 and 2 wk when stored at 7.2°C and 12.8°C, respectively. C. botulinum population significantly (P < 0.05) increased to 5.26 log at 2 wk in control samples stored at 12.8°C. In contrast, no C. botulinum growth or toxin production was observed in samples containing antimicrobials stored at 7.2°C and 12.8°C through 20 wk.

Conclusion: The application of clean label antimicrobials were efficacious in delaying the botulinal toxicity formation similar to sodium nitrite in ground turkey for over 20 wk.

Keywords: C. botulinum, food safety, poultry, uncured

182 LISTERIA MONOCYTOGENES RISK DUE TO INADEQUATE INACTIVATION DURING SOUS VIDE COOKING AND SUBSEQUENT REFRIGERATION

I. Ribero^1,*, A. Manzoor¹, L. Lagos¹, M. Stewart¹, K. Vestergaard¹, M. Nunez¹, S. Suarez¹, B. Castanho¹, J. M. Scheffler¹, ¹Department of Animal Sciences, University of Florida, Gainesville, Florida, United States *jmscheff@ufl.edu

Objectives: Sous vide cooking, where vacuum-packaged meat is submerged in water to cook for a long time at a low temperature, is popular in the food service industry to manage timing and consistency during large services. While the FSIS Cooking Guidelines for Meat and Poultry Products classifies Salmonella as the benchmark for lethality, previous work in our lab suggests Listeria monocytogenes (LM) is more resilient to inactivation during sous vide cooking, potentially resulting in insufficient inactivation. Prior exposure to heat stress may also impart adaptation to other stressors. The objective of this study is to evaluate the survival dynamics of LM in sub-optimally cooked and raw vacuum-packaged beef.

Materials and Methods: Eye of round steaks (2.54 cm thick, 100 ± 3g, n = 86) were cut and inoculated with 3 strains of LM on each side. LM was inoculated at 5 log CFU/g and left raw for unstressed treatment, whereas LM was inoculated at 8 log CFU/g and heat stressed by sous vide conditions predicted to result in a 3 log CFU/g reduction. After attachment, samples were vacuum sealed, and sous vide steaks were cooked at 57.5°C for 45 min. Steaks were crash chilled after cooking and refrigerated at 4°C. Steaks were sampled before and after cooking, and every 48 h out to 14 d. LM was recovered with 100 mL of 0.1% peptone water, serially diluted, and enumerated by mixing 1 mL diluent with 4 mL molten tryptic soy agar, and overlayed onto modified Oxford agar plates. Plates were incubated at 35°C and enumerated at 20 to 24 h. Data were analyzed using mixed linear model with LM type (stressed vs unstressed) and storage periods as fixed effect and replicates as random effect.

Results: LM on sous vide steaks reduced from 8.12 ± 0.15 to 5.17 ± 0.21 after sous vide cooking (heat stress). At the start of storage, LM was similar (P = 0.98) between stressed and unstressed treatments. Within each treatment, there was no significant change (P > 0.72) in the concentration of LM observed over 14 d storage. However, LM was higher (P < 0.001) in unstressed steaks than stressed steaks at d 14 (5.85 vs 4.36 log CFU/g).

Conclusion: Prior exposure to heat stress applied to LM during sous vide did not show any change in survival when compared to unstressed LM on vacuum sealed beef. There was no net growth or inactivation of LM observed. The changes in concentrations of LM observed at 14 d would likely have little biological relevance as facilities who use sous vide are unlikely to keep steaks for up to 2 wk in the fridge. These data suggest that refrigeration, regardless of prior heat stress, makes a negligible contribution to an overall risk assessment of sous vide cookery.

Funding Source: Florida Beef Council

Keywords: beef, food service, risk management, vacuum packaging

183 EFFICACY OF LIQUID SMOKE SYSTEMS ON FOOD SPOILAGE AND PATHOGENIC MICROORGANISMS

N. Hall^1,*, S. Wason¹, M. McCusker², J. Saha¹, S. Kumar¹, ¹Food Protection and Preservation, Kerry, Beloit, Wisconsin, United States, ²Food Protection and Preservation, Kerry, Naas, Ireland *nicolette.hall@kerry.com

Objectives: Smoke systems could provide antimicrobial properties in treated food products. This study aimed to evaluate the antimicrobial effectiveness of various liquid smokes against a range of microorganisms, including spoilage and pathogenic bacteria.

Materials and Methods: Three liquid smokes (F1, F2, and F3) were tested at 0% to 4% concentrations in selective media adjusted to pH 6.0. The media were inoculated with spoilage bacteria (Lactobacillus sakei, Leuconostoc mesenteroides) and pathogens (Listeria monocytogenes, Salmonella Typhimurium, Staphylococcus aureus). Growth dynamics were monitored at 30°C using Bioscreen-C Pro. Each smoke sample was evaluated in duplicate at every concentration level. The modified Gompertz equation was employed to calculate maximum growth rates (μmax; h^⁻¹) and lag phases (h), defining the minimum inhibitory concentration (MIC). A one-way ANOVA (P < 0.05) was used for data analysis.

Results: F1, F2, and F3 demonstrated MIC values across all tested bacteria. The MIC of F1, F2 and F3 against Lactobacillus sakei was 0.25%, 0.5%, and 2.0% respectively. F1 and F2 had an MIC of 0.5% against Leuconostoc mesenteroides while F3 exhibited an MIC of 1.5%. Against all pathogenic bacteria, F1 was particularly effective with MIC at 0.25%. F2 and F3 also notably reduced the growth rate and extended the lag phase of pathogenic strains with MIC at 1.0%.

Conclusion: The findings highlight the effectiveness of the antimicrobial properties of liquid smoke systems in food products.

Keywords: antimicrobials, in vitro, pathogen, smoke, spoilage

184 PREDICTING SALMONELLA ENTERICA AND LISTERIA MONOCYTOGENES INACTIVATION DYNAMICS DURING SOUS VIDE COOKING OF INTACT AND TENDERIZED BEEF STEAKS

A. Manzoor^1,*, G. Allen¹, L. Lagos¹, B. Castanho¹, A. Havelaar^1,2,3, J. M. Scheffler¹, ¹Department of Animal Sciences, ²Emerging Pathogens Institute, ³Global Food Systems Institute, University of Florida, Gainesville, Florida, United States *jmscheff@ufl.edu

Objectives: Sous vide, cooking of vacuum-packed food at lower temperatures (50°C to 95°C) for longer periods in water baths, is popular in restaurants and food service industry due to its benefits, including uniform cooking, precise control over doneness, process management, and extended shelf-life compared to traditional cooking methods. Sous vide cooking is generally considered safe. However, using a lower temperature than traditional cooking methods without appropriate time to seek certain eating characteristics may introduce unnecessary risk. Salmonella and Listeria monocytogenes are among the top 5 causative agents associated with red meat-related foodborne outbreaks. This study aimed to determine the time and temperature combinations required to inactivate Salmonella and Listeria during sous vide cooking.

Materials and Methods: Eye of round steaks (100 ± 3g and 2.54 cm thick) were individually surface inoculated at a target concentration of 8 log cfu/g with 5 strains of Salmonella enterica and 3 strains of Listeria monocytogenes. A jaccard was used to tenderize a subset of steaks. Following a 30-min pathogen attachment period, steaks were vacuum packaged and cooked at temperatures of 52.5°C, 57.5°C, 60°C, and 62.5°C up to 450 min, 90 min, 56 min, and 35 min, respectively (34 steaks per replicate). Samples were collected for enumeration at 45 min, 15 min, 8 min, and 5 min intervals, respectively. Intact steaks were hand massaged in peptone water while tenderized steaks were thinly sliced with a sterile blade to account for internalized pathogens. Salmonella and Listeria were enumerated using xylose lysine tergitol agar and modified Oxford agar, respectively. Tryptic soy agar overlay method was used to account for sublethally injured cells. These experiments were independently replicated 5 times. The Weibull and linear model were fitted on microbial inactivation data using gnls() and lm() functions in nlme package and base R, respectively in R Version 4.2.1. Model selection was based on a lower AICc value. The Weibull model considers the variation in the inactivation rates of microbial populations.

Results: Both Salmonella and Listeria at all temperatures followed Weibull inactivation model except Salmonella in intact steaks at 60°C and in tenderized steaks at 52°C where a linear model was a better fit. We observed that Salmonella was reduced to below detection limit quicker than Listeria at all temperatures when given sufficient time. For intact steaks at 62.5°C, a 6.5 log cfu/g reduction in Salmonella was observed in 14 min compared to 25 min for Listeria. For tenderized steaks at 62.5°C, the 6.5-log reduction in Salmonella was achieved in 23 min while for Listeria it took 33 min. Inactivation rate of Salmonella was also higher in intact steaks than tenderized ones (29 vs 37 min to 6.5-log reduction at 57.5°C) except at 60°C. A higher Listeria inactivation rate in intact steaks was only observed at 62.5°C.

Conclusion: USDA considers Salmonella a pathogen lethality indicator; however, we observed that it is inactivated quicker in sous-vide conditions than Listeria suggesting Listeria may be the better indicator for sous vide cookery. A 6.5 log inactivation for both pathogens can be achieved at 52.5°C; however, it can fall under the upper temperature limit for Clostridium perfringens growth.

Funding Source: Florida Beef Council

Keywords: beef, non-intact, nonlinear modeling, risk management

185 CONTROL OF C. PERFRINGENS SPORE OUTGROWTH USING ANTIMICROBIAL INGREDIENTS DURING EXTENDED COOLING OF UNCURED TURKEY

T. Verma^1,*, G. Mccoy¹, B. Howard¹, R. Ames², R. Garza², L. Brown¹, ¹Research and Development, ²Business Development, Corbion, Lenexa, Kansas, United States *garrett.mccoy@corbion.com

Objectives: C. perfringens is a major concern in meat products that are cooled slowly, which allows the surviving bacterial spores to germinate, outgrow, and produce toxins. The USDA-FSIS Appendix B Stabilization guideline defines the cooling limits for uncured meat and poultry products to inhibit the outgrowth of C. perfringens. However, inadequate cooling and process deviations may result in the outgrowth of C. perfringens. The objective of this study was to evaluate the efficacy of conventional and clean-label antimicrobials to inhibit the C. perfringens spore outgrowth during extended cooling of uncured turkey breast.

Materials and Methods: Boneless, skinless turkey breasts were ground and formulated with 5 treatments (no antimicrobial, 2.14% Opti.Form® PD 4, 0.75% Verdad® Powder N6, 1% Verdad® Powder N30, and 1.5% Verdad® Opti Powder N510. The formulated ground turkey was inoculated with a 4-strain C. perfringens cocktail (NCTC 8798, NCTC 10240, NCTC 10613, NCTC 11144) at ca. 3.0 log CFU/g. Samples (25 g) were portioned into boilable, oxygen- and moisture-impermeable bags, vacuum-sealed, immersed in a water bath, and heated with agitation until the product temperature reached 73.5°C. After cooking, the samples were transferred to a water bath preset at 54.4°C for 10 min to allow the cooked meat to equilibrate. Post-equilibration, the cooked samples were transferred to a programmable water bath for the dynamic cooling schedule. Samples were cooled from 54.4 to 26.7°C in either 2 or 5 h, then from 26.7 to 4.4°C in either 8 or 10 h (Total cooling time—D1: 10 h, and D2: 15 h). After completion of the cooling cycle, the cooked meat was removed from the water bath, transferred to a sterile stomacher bag, diluted in a 1:2 weight with buffered peptone water, and stomached at 200 rpm for 30 s. The samples were spread-plated onto Tryptose Sulfite Cycloserine agar and incubated anaerobically at 37°C for 24 ± 2 h. A split-plot factorial design was used to perform the experiment where the cooling temperature was used as a whole-plot and treatments were applied as a split-plot. Minitab 20.2 was used to test the significance among the treatments at α = 0.05. Another set of samples was analyzed for pH (1:9 dilution with distilled water), moisture content (AACC method 44-15.02), and water activity (AquaLab Lite 4TE).

Results: The proximate values of cooked meat for all treatments are shown in Table 1. The initial population of C. perfringens spores before starting the dynamic cooling process was averaged 3.18 ± 0.25 log spores/g. The C. perfringens population increased by 0.52 and 3.14 log in cooked meat without antimicrobials during D1 and D2 cooling, respectively. The C. perfringens outgrowth was inhibited (<1 log) in samples containing antimicrobials for all the tested cooling profiles. Samples containing 1.5% Verdad® Opti Powder N510 had a significant (P < 0.05) reduction in C. perfringens population (0.75 to 1.03 log) as the cooling time increased from 10 h to 15 h.

Conclusion: The application of conventional and clean-label antimicrobial ingredients effectively inhibited the outgrowth of C. perfringens to <1 log in uncured meat during extended cooling. The inclusion of the tested antimicrobials will assist the meat processors in complying with USDA-FSIS Appendix B guidelines (<1 log C. perfringens outgrowth) during customized extended cooling schedules.

Keywords: C. perfringens, food safety, predictive microbiology, uncured

186 FECAL SHEDDING OF POTENTIALLY PATHOGENIC ORGANISMS AND FECAL MICROBIOME DYSBIOSIS OF CATTLE EXPOSED TO DIFFERENT LEVELS OF TRANSPORTATION STRESS

A. L. Krikorian^1,*, L. Burdette², W. B. Smith¹, J. Sawyer¹, A. D. Belk¹, ¹Animal Sciences, ²Alabama Agricultural Experiment Station, Auburn University, Auburn, Alabama, United States *alk0045@auburn.edu

Objectives: Transportation stress is a well-known problem facing the beef cattle industry especially in the southeastern United States, where cattle often must travel large distances to reach feeding and harvest facilities. It has previously been shown that this stress can impact fecal shedding of pathogens and, through that, meat safety, but causes of this are still unclear. The objective of this study, therefore, was to determine the relationship between gut microbial community and pathogen presence in cattle under different levels of transportation stress to clarify food safety risks.

Materials and Methods: Seventeen Angus-based heifers with no more than ¼ Brahman influence were used to determine the relationship between gut microbial community and pathogen presence in cattle under different levels of transportation stress. Behavioral and biological samples were collected before and after the transportation event (2.5 or 12 h travel time). This consisted of body weight (kg), exit velocity (m/s), and microbial colony counts (aerobic plate counts, Escherichia coli and coliform counts, and Salmonella counts). Microbiome samples were collected via sterile double headed swabs and used for DNA extraction and sequencing for the 16S rRNA gene. Behavioral and biological samples were analyzed as a completely randomized design and tested using t-test and microbiome data were analyzed using the QIIME2 platform and R software following standard bioinformatic analysis methods. Significance was identified as P < 0.05.

Results: Overall, the main factors impacted by the difference in transportation time were body weight, Escherichia coli shedding, and microbiome structure. There was a difference (P < 0.05) in the shrinkage (decrease in body weight) between the 2.5-h (−12.7 kg) and 12-h transport (−21.3 kg), and there was a difference (P < 0.05) in the proliferation of E. coli (0 logCFU/g to 2.14 logCFU/g) between the 2.5-h and 12-h transport event. Furthermore, there was a trend (P = 0.09) for cattle to have faster exit velocities after the 12-h transport time which indicates a tendency for more excitable behavior and illuminating the state of stress the animals were experiencing. Additionally, the microbiome data analysis revealed a dysbiosis in the gut microbiome with the 12-h transportation, as indicated by a decrease (P < 0.05) in the Firmicutes:Bacteroidotas ratio. Moreover, animals under longer transportation had a decrease (P < 0.05) in fecal microbial diversity. This window could allow organisms to dominate the environment which could allow organisms like E. coli to proliferate resulting in a risk for food safety when processed.

Conclusion: The results of this study suggest that transportation stress can influence cattle’s physiological and biological levels as well as influence the fecal microbiome. This illuminates the impact of transportation stress on cattle that are produced large distances from the main network of the beef supply chain and how producers should consider techniques to mitigate this stress from their animals.

Funding Source: Alabama Beef Check-off

Keywords: dysbiosis, E. coli, microbiome, STRESS, transportation stress

187 BIOMAPPING AND QUANTIFICATION OF SALMONELLA IN SOW AND BOAR LYMPH NODES AND TONSILS TO ASSESS RISK IN PORK PRODUCTS

R. L. Jimenez^1,*, S. Zhang², S. E. Gragg², M. X. Sanchez-Plata¹, M. M. Brashears¹, ¹ICFIE, Texas Tech University, Lubbock, Texas, United States, ²Animal and Dairy Sciences, University of Wisconsin-Madison, Madison, Wisconsin, United States *reagan.brashears@ttu.edu

Objectives: Previous commercial pork biomapping studies have indicated that lymph nodes (LN) can be a reservoir for Salmonella in meat processing operations. Salmonella housed in the LN and tonsils of sows and boars have not been explored and can lead to potential contamination of the carcass and further processed pork products. The objective of this study was to determine the prevalence of Salmonella in the tonsils and various LN from sows and boars harvested throughout the United States in order to determine the risk of contamination that these structures hold and their potential impact on public health.

Materials and Methods: Sows and boars were harvested at 3 commercial pork processing facilities throughout the United States in the winter season. From each carcass, the subiliac, superficial inguinal, axillary, pre-scapular, mesenteric, and tracheobronchial LN were collected, as well as the corresponding tonsil (n = 735). Each structure was trimmed of attached fat, tissue, and facia before being weighed, boiled, and macerated. The samples were then processed for Salmonella detection and quantification using the Hygiena’s BAX® System SalQuant^™.

Results: The overall Salmonella prevalence for all collected samples was 8.57% (63/735 samples). Sample type specific, the Salmonella prevalence was 32.38% in tonsils, 22.85% in mesenteric, 2.85% in axillarys, 0.95% in both subiliac and pre-scapular LN, and 0% for the remaining LN varieties. Only mesenteric LN and tonsils were quantifiable, and displayed an average Salmonella load of 1.8 LOG10CFU/LN.

Conclusion: The results of this study indicate that the highest Salmonella prevalence was observed in mesenteric LN and tonsils. While neither of these structures are directly incorporated into further processed products, they still pose a public health risk of potential cross-contamination during processing. The remaining variety of LN that have displayed a lower prevalence of Salmonella may be incorporated in ground product; therefore, further research is needed to determine how to mitigate the risk of contamination associated with LN and tonsils in sows and boars further processed pork products.

Funding Source: The funding for this study was provided by the Foundation for Meat and Poultry Research and Education.

Keywords: boar, lymph nodes, pork, Salmonella, sow

188 SALMONELLA QUANTIFICATION IN POULTRY ALONG THE SUPPLY CHAIN

L. Lee^1,*, K. B. Gehring¹, J. W. Savell¹, K. A. Doria¹, ¹Animal Science, Texas A&M University, College Station, Texas, United States *lee99@tamu.edu

Objectives: The objectives of this project were 1) to evaluate the presence of Salmonella in the following retail products: ground chicken, ground chicken breast, ground turkey, ground turkey breast, chicken gizzards, chicken livers, bone-in chicken thighs, bone-in, skin-on chicken breasts, boneless, skinless chicken breasts, boneless, skinless chicken thighs, chicken breast tenders, and chicken drumsticks, and 2) to determine if home storage conditions impact prevalence of Salmonella.

Materials and Methods: Packages (n = 45 per item; total 540) of ground chicken, ground chicken breast, ground turkey, ground turkey breast, chicken gizzards, chicken livers, bone-in thighs, bone-in, skin-on breasts, boneless, skinless breasts, boneless, skinless thighs, breast tenders, and drumsticks) were purchased at retail stores in Bryan and College Station, TX based on availability. Products were transported to Texas A&M University’s Meat Science Laboratory, 15 packages of each product type were assigned to one of the following storage treatment groups: 1) sampled on the day of purchase; 2) refrigerated for 3 d and then sampled, 3) refrigerated for 3 d, frozen, thawed, and then sampled. Products assigned to treatment group 1 were sampled on the day of purchase. Products assigned to treatment groups 2 and 3 were placed immediately under refrigerated storage (∼3°C) for 72 h. After 72 h, products assigned to treatment group 2 were sampled, and products assigned to treatment group 3 were placed in a freezer (∼20°C). After 48 h, products were removed from the freezer and allowed to thaw in refrigerated storage (∼3°C). For all ground chicken and turkey products, a 325 g sample was added to 1,625 mL Buffered Peptone Water (BPW) and homogenized by hand until all comminuted products were evenly dispersed. For non-ground chicken products, the rinsate method was used. All samples were incubated for 8 h at 42°C ± 1°C. Prevalence and quantification were determined using the Bax® System SalQuant® methodology approved by AOAC (Hygiena, 2021). Data were analyzed using JMP Pro Software 16.0 (SAS Institute, Inc., Cary, NC).

Results: Positivity rates across all 3 treatments groups were determined for each poultry product type: bone-in chicken thighs (0%), bone-in, skin-on chicken breast (0.044%), boneless, skinless chicken breast (0%), boneless, skinless chicken thighs (0%), chicken breast tenders (0%), chicken drumsticks (0.022%), chicken gizzards (0.688%), ground chicken (0%), ground chicken breast (0.066%), ground turkey (0.044%), ground turkey breast (0%), and chicken livers (0.533%). Positivity rates were also determined for each treatment group across all product types: treatment group 1 (0.183%), treatment group 2 (0.111%), and treatment group 3 (0.055%).

Conclusion: Based on USDA’s Food Safety and Inspection Service data, the prevalence of Salmonella in poultry has decreased, but according to the Centers for Disease Control and Prevention data the incidence of salmonellosis associated with poultry products continues to increase. Data from this project support that the prevalence of Salmonella in retail poultry products is low, and that normal storage practices applied by consumers, including freezing and thawing, did not increase the presence of Salmonella on these products. Further research could be conducted to look at improper storage practices or longer storage times.

Funding Source: Funded in part by the USDA-FSIS/ORISE, Food Safety Fellow Program.

Keywords: meat safety, poultry, Salmonella

189 SHELF LIFE EXTENSION OF READY-TO-EAT CHICKEN SALAD USING A NOVEL CULTURED DEXTROSE ANTIMICROBIAL

F. Sumargo^1,*, E. Lii¹, G. Mccoy¹, B. Howard¹, A. Beckett², R. Ames², R. Garza², ¹Research and Development, ²Business Development, Corbion, Lenexa, Kansas, United States *garrett.mccoy@corbion.com

Objectives: The growing popularity of the prepared deli salad segment is characterized by their ease of preparation, quick consumption, and accessibility. However, the increasing demand for a clean-label antimicrobial paired with prolonged shelf life poses a greater microbiological challenge for such foods due to (i) the extensive handling (shredding, mixing, and packaging) post-cooking, and (ii) the addition of vegetables and mayonnaise to the product. The objective of this study was to evaluate the efficacy of novel clean-label cultured dextrose-based antimicrobials to extend the overall shelf life of ready-to-eat chicken salad.

Materials and Methods: Raw chicken breasts were tumbled with 15% (w/w) brine solution for 1 h under vacuum. Post-tumbling, chicken breasts were vacuum packaged and cooked-in-bag in a smokehouse until the internal temperature reached 73.8°C (165°F). Cooked chicken breast was coarsely shredded with a pilot scale bowl chopper. The mayonnaise-based dressing was emulsified using a handheld mixer and formulated with 4 treatments [no antimicrobial; Conventional antimicrobial (0.05% (w/w) Potassium sorbate and 0.05% (w/w) Sodium benzoate); 0.75% (w/w) Verdad® Opti Powder N365; 0.75% (w/w) Verdad® Opti Powder N370]. The emulsified dressing, the raw vegetables, and the shredded chicken breast were mixed for at least 3 min to ensure homogeneity. Fully mixed samples were individually portioned into 50 g, packed in a 3 mil 4 X 5-inch polyproline bag, heat sealed, and kept at 4.4°C for microbiological sampling. On sampling day, a triplicate of the chicken salad sample from each treatment was transferred into a sterile stomacher bag to which a 1:2 weight of buffered peptone water was added. The sample-diluent mixture was stomached at 200 rpm for 30 s. The samples were spread-plated on de Man, Rogosa, and Sharpe agar for lactic acid bacteria (LAB) and plates were incubated at 30°C for 48 h. Another set of samples were analyzed for pH (1:9 dilution with distilled water), water activity (Aqualab 4TE), and moisture content (AACC methods 44-15.02). Statistical analysis was conducted using Minitab Version 20. Two factors Analysis of Variance with the repeated measured design was used to compare the efficacy between treatments and bacterial growth within treatment over time. The microbial growth was modeled following Baranyi and Robert’s equation to estimate the growth rate and lag time.

Results: The proximate values of chicken salad were 5.17 ± 0.13 pH, 0.980 ± 0.002 water activity, and 62.51 ± 1.19% moisture. The initial LAB population ranged from 2.14 to 2.47 log CFU/g. The outgrowth of the LAB population reached 6-log on day 42 with a predicted growth rate of 0.190 d⁻¹ in the samples containing no antimicrobial. No significant (P > 0.05) outgrowth of the LAB population was observed (predicted growth rate was <0.001 d⁻¹) in the sample with the addition of antimicrobials. Table 1 shows the enumeration of the LAB population of each treatment, changes over time, and growth rate.

Conclusion: The novel cultured dextrose-based antimicrobial successfully extended the shelf life of refrigerated chicken salad beyond 40 d as indicated by the predicted growth rate of <0.001 d⁻¹. Additionally, the study indicated that Verdad® Opti Powder N365 & Verdad® Opti Powder N370 exhibited the same efficacy as conventional antimicrobials and could be used as clean-label alternatives.

Keywords: ready-to-eat products (RTE), shelf life

190 ENUMERATION OF LISTERIA SPP. USING A DRY, AND A PRE-MOIST MICROTALLY® MITT AND COMPARED TO A PRE-MOIST STICKSPONGE^™ FOR THE ENVIRONMENTAL SAMPLING OF THREE DIFFERENT INOCULATED SURFACES

E. Orellana Pizzato^1,*, Q. Hull¹, R. Soler-Diaz¹, M. Brashears¹, M. X. Sanchez-Plata¹, ¹Animal and food sciences, Texas Tech, Lubbock, Texas, United States estorell@ttu.edu

Objectives: The objective of this study was to assess the efficacy of MicroTally® Mitt (dry and pre-moist) as compared to the conventional pre-moistened StickSponge^™ in the detection of Listeria spp. in inoculated environmental samples, including stainless-steel sheet (SS), a Teflon Cutting Board (TB), and stainless-steel drains (SD) surfaces.

Materials and Methods: Environmental swab StickSponge^™ samples (n = 54) and MicroTally® (pre-moist) Mitt samples (n = 54) with 25 mL of Buffered Peptone Water (BPW) and (n = 54) dry mitts were collected from 3 different inoculated surfaces. Samples were inoculated with a cocktail of L. monocytogenes, L. innocua, and L. welshimeri at 5 Log CFU/cm². One sponge and mitt per sample was taken, the surface was swabbed for 30 s on each side. A 200 mL aliquot BPW for the dry mitt and a 25 mL aliquot of BPW was added before taking the sample to the pre-moist mitt. All samples were stomached for 30 s at 230rpm. The presence of Listeria spp. was plated following the spread plate methodology on Modified Oxford Medium (MOX) for confirmation and enumeration. Data was analyzed with R software. An Anova statistical test was performed to evaluate the difference between treatments and surfaces, followed by a Tukey analysis for mean separation evaluation. A linear regression model was performed to compare the load of dry mitt and pre-moist mitt with swabs to evaluate performance of both sampling methods. All data was evaluated at 95% confidence level.

Results: Statistically significant differences in recovery rates between swabs and both mitt sampling methods were found in the study (ANOVA, P < 0.05), indicating a different performance for the two approaches. Swab and Dry Mitt (0.1131) was significant different from 1, when the interval confidence of the slope was calculated (97.5% = 0.3766). In the linear model the intercept represents the measurement obtained with the dependent variable when the independent variable is equal to zero, in this case, the intercept (−0.3727) was statistically equal to zero (P = 0.213), the R² (−0.01). Swab and Pre-Moist Mitt (0.8738) was significant different from 1, when the interval confidence of the slope was calculated (97.5% = 1.1085). Furthermore, the intercept (−0.4647) was statistically equal to zero (P = 0.0386), the R² (0.70) so both methodologies represent a low fit of the data to the linear model.