Introduction
Postmortem aging is a widely adopted practice in the beef industry to enhance tenderness, palatability, and overall consumer acceptance (Smith et al., 2008). It is well-established that refrigerated aging improves meat tenderness by facilitating enzymatic activity that breaks down muscle structure (Bratcher et al., 2005; Gruber et al., 2006; Huff-Lonergan et al., 2010; Colle et al., 2015). However, the optimal duration of aging can vary significantly across muscle types due to differences in muscle traits and characteristics (Gruber et al., 2006). Wet aging, in particular, involves vacuum-sealing meat in barrier packaging and storing it under refrigerated conditions for an extended period to optimize tenderness and flavor.
As one of the largest agricultural commodities in the United States, beef’s market success is largely driven by flavor, a top consumer preference factor (Kerth et al., 2024; O’Quinn et al., 2024). Although the tenderizing effects of aging are well-documented, the influence of aging duration on beef flavor remains to be fully understood (Huff-Lonergan et al., 2010; Colle et al., 2015; Miller, 2020; O’Quinn et al., 2024). Recent literature has reported an increase in off-flavor development during extended aging (Evers et al., 2020; Foraker et al., 2020; Barker et al., 2023; Hernandez et al., 2023). However, these studies were limited to the Longissimus lumborum. Individual muscles in a beef carcass possess unique biochemical characteristics that influence tenderness and flavor development (Rhee et al., 2004; Anderson et al., 2012; Hammond et al., 2022). Thus, more research is required to fully understand tenderness and flavor development in extended-aged beef cuts outside of the middle meats. Therefore, the objective of this study was to characterize the influence of wet aging on Biceps femoris (BF), Gluteus medius (GM), and Semimembranosus (SM) descriptive-sensory attributes, consumer liking, and instrumental tenderness and color measurements.
Materials and Methods
All procedures involving human subjects for consumer-sensory evaluation were approved by the Kansas State University Institutional Review Board (IRB #7440) and conducted in accordance with institutional requirements. Texas Tech University (TTU) determined that descriptive-sensory analysis panel procedures were qualified for exemption under category 6.
Carcass selection and sample collection
Eighty beef carcasses with a US Department of Agriculture (USDA) marbling score of Modest (500–599), as determined during routine carcass grading at the commercial processing facility, and no quality defects were selected from a commercial processing facility in West Texas. Subprimals were collected from carcasses at approximately 48 h postmortem. Personnel from TTU collected paired top sirloin butt subprimals (Institutional Meat Purchase Specifications [IMPS] #184, North American Meat Processors Association [NAMP] 2014) and 1 inside round subprimal (IMPS #168, NAMP 2014) from each carcass, yielding a total of 160 top sirloin butt subprimals and 80 inside round subprimals. Subprimals were collected across 2 separate trips to accommodate storage space. Subprimals were transported at (0–4°C) to the Gordon W. Davis Meat Laboratory in Lubbock, Texas.
Each carcass was randomly assigned to 1 of 8 aging durations, (14, 28, 35, 42, 49, 56, 63, or 70 d) with 10 carcasses from each collection allocated to each aging duration (10 carcasses/aging duration). Subprimals remained in their original vacuum packaging and were boxed and placed on racks in a dark cooler at a constant temperature of approximately 2.2°C plus or minus 0.02°C until the assigned aging period was completed. Refrigerator temperatures were continuously monitored using Elitech RC-4 temperature recorders (Elitech, San Jose, CA) to ensure consistent storage conditions.
Subprimal fabrication
Fabrication was conducted on the designated aging duration date. Trained TTU personnel fabricated each top sirloin butt subprimal into GM and BF muscles, while the inside round subprimals were fabricated into the SM muscle. The BF, GM, and SM muscles were then sliced into 2.54-cm steaks using a commercial slicer (Hobart, Troy, OH). Two sister steaks were allocated to consumer-sensory analysis, whereas descriptive-sensory analysis and shear-force analysis were allotted 1 steak each, vacuum packaged, and stored at −20°C until subsequent analysis. Frozen steaks allotted for consumer-sensory and shear-force analysis were transported to Kansas State University, at 0°C to 4°C. A steak for raw analyses (instrumental color and pH) was allowed to bloom for 30 min, and instrumental color was measured. Following color measurement, steaks were trimmed of fat and connective tissue then snap frozen in liquid nitrogen and pulverized using a commercial food blender (Ninja®, Needham, MA). Homogenates were stored in labeled bags at −80°C until subsequent analysis.
pH
The pH of each previously homogenized raw sample was measured. A 1-g portion of the sample was weighed into a 50-mL conical tube, and 9 mL of deionized water was added. The sample was vortexed for 60 s to create a slurry. The pH of the slurry was measured in triplicate using a calibrated pH meter (FE150, Fisherbrand, Pittsburgh, PA). Individual measurements were averaged for statistical analysis.
Consumer-sensory analysis
Consumer-sensory panelists (N = 288) were recruited from Manhattan, Kansas, and the surrounding communities and were monetarily compensated for their participation. Steak samples were thawed under refrigeration at approximately 2°C to 4°C for up to 24 h. Steaks were cooked on a commercial flat-top griddle set to 190.5°C (Cooking Performance Group, 48” Electric Countertop Griddle, Lancaster, PA). Internal steak temperatures were monitored and recorded using thermocouples connected to a Doric 205 device (Beckman Industrial, San Diego, CA). The BF steaks were cooked to an internal temperature of 49°C, flipped and removed at 68°C; GM steaks were cooked to an internal temperature of 41°C, flipped and removed at 69°C; and SM steaks were cooked to an internal temperature of 41°C and flipped and removed at 68°C. Steaks were removed from the grill at determined internal temperatures to result in a peak temperature of approximately 71°C.
Steaks were divided into equal thirds and served to panelists. Panelists evaluated 5 samples per session from the same muscle type for overall liking, flavor liking, tenderness liking, and juiciness liking. Each panelist participated in a single session, and samples representing aging periods were distributed across sessions to ensure balanced representation. Evaluations were made using a 10-point hedonic scale, where 0 = dislike extremely, 5 = neither like nor dislike, and 10 = like extremely. Panelists also indicated the acceptability of each sample (yes/no). Demographic questions and sensory responses were recorded on electronic tablets (Model 5709 HP Stream 7, Hewlett-Packard, Palo Alto, CA) using a digital survey platform (Qualtrics Software, Provo, UT).
Warner-Bratzler shear force
Steaks were thawed and cooked using the same procedures outlined for the consumer-sensory panel analysis. Following cooking, steaks were chilled for 24 h at 2°C to 4°C before conducting Warner-Bratzler shear force (WBSF) according to the American Meat Science Association (AMSA) meat cookery, sensory evaluation, and meat tenderness guidelines (AMSA, 2016). Six cores (1.27-cm diameter) were excised from each steak, with cuts made parallel to the muscle-fiber orientation. Each core was sheared perpendicular to the muscle-fiber orientation using an Instron testing machine (Model 5569, Instron Corp., Canton, MA) equipped with a crosshead speed of 250 mm/min and a load cell capacity of 100 kg. The peak force for all 6 cores was recorded, and the results were averaged to calculate the average peak shear force (kilograms).
Descriptive-sensory analysis
The training, validation, and evaluation of trained sensory panelists were conducted following the guidelines established by the AMSA (2016) and the Beef Flavor Lexicon by Adhikari et al. (2011). The sensory attributes, definitions, and reference standards presented in Table 1 were adopted from these established resources and were used throughout panelist training and evaluation for calibration and intensity standardization. Panelists were trained for approximately 30 h prior to validation and evaluation. During training, panelists were introduced to each sensory attribute and corresponding reference standard and were instructed on the use of the 0 to 15 universal intensity scale, where 0 = not detectable and 15 = extremely intense. Panelists were trained to score attributes relative to the provided standards and verbal intensity concepts to improve scoring consistency across sessions. Panelists completed 4 individual validation sessions for each muscle, with 8 extra samples from the study, prior to formal evaluation.
Definitions and standard references for descriptive beef flavor and texture attributes, where 0 = extremely dry/tough/not detectable and 15 = extremely juicy/tender/intense, from Adhikari et al. (2011) and AMSA (2016)
| Attribute | Definition | Reference |
|---|---|---|
| Muscle-fiber tenderness | The ease in which the muscle-fiber fragments during mastication | Select eye of round cooked to 70°C = 9.0; tenderloin cooked to 70°C = 14.0 |
| Connective tissue | The structural component of the muscle surrounding the tissue amounts during mastication | Brisket steak cooked to 70°C = 7.0; tenderloin cooked to 70°C = 14.0 |
| Juiciness | The amount of perceived juice that is released from the product during mastication | Carrot = 8.5; mushroom = 10.0; cucumber = 12.0; apple = 13.5; watermelon = 15.0; Choice top loin steak cooked to 58°C = 11.0; Choice top loin steak cooked to 80°C = 9.0 |
| Beef identity | Amount of beef flavor in sample | Swanson’s beef broth = 5.0; 80% lean ground beef = 7.0; beef brisket = 11.0 |
| Browned/roasted | A round, full aromatic generally associated with beef suet that has been broiled | Beef suet = 8.0 |
| Bloody/serumy | The aromatics associated with blood on cooked meat products; closely related to metallic | USDA choice strip steak = 5.5; beef brisket = 6.0 |
| Fat-like | The aromatics associated with cooked animal fat | Hillshire Farms Lit’l Beef Smokies = 7.0 |
| Metallic | The impression of slightly oxidized metals such as iron, copper, and silver spoons | 0.10% potassium chloride solution = 1.5; Dole canned pineapple juice =6.0 |
| Liver-like | The aromatics associated with cooked organ meat/liver | Beef liver = 7.5 |
| Bitter | The fundamental taste factor associated with caffeine solution | 0.01% caffeine solution = 2.0; 0.02% caffeine solution = 3.5 |
| Salty | The fundamental taste factor associated with a sodium chloride solution | 0.15% sodium chloride solution = 1.5; 0.25% sodium chloride solution = 3.5 |
| Sweet | Fundamental taste factor associated with sucrose | 2.0% sucrose solution = 2.0 |
| Sour | The fundamental taste factor associated with citric acid | 0.015% citric acid solution = 1.5; 0.050% citric acid solution = 3.5 |
| Umami | Flat, salty, somewhat brothy, that taste of glutamate, salts of amino acids and other molecules called nucleotides | 0.035% accent flavor enhancer solution = 7.5 |
| Musty/earthy/humus | Musty, sweet, decaying vegetation | Mushrooms = 10.0; hazelnuts = 5.0 |
| Cardboardy | Aromatic associated with slightly oxidized fats and oils, reminiscence of wet cardboard packaging | Dry cardboard (1 in2) = 5.0; wet cardboard soaked in water (1 c) for 30 min = 7.0 |
| Painty | Aromatic associated with extensively oxidized fats and oils, paint thinner, varnish | Old beef tallow = 10.0; old Pringles = 13.0 |
| Burnt | The sharp/acrid flavor note associated with overcooked pork muscle, something overbaked, or excessively browned in oil | Alf’s red wheat puffs = 5.0 |
| Heated oil | The aromatics associated with oil heated to a high temperature | Wesson vegetable oil (1/2 c) microwaved (3 min) = 7.0; Lay’s potato chips = 4.0 |
| Buttery | Sweet, dairy like aromatic associated with natural butter | Land O’Lakes unsalted (1/2 tbsp) = 7.0 |
Abbreviation: USDA, US Department of Agriculture.
Prior to each evaluation session, panelists were provided with a warm-up sample, which was evaluated and discussed to ensure calibration among panelists. During evaluation sessions, panelists were provided with deionized water, unsalted saltine crackers, and plain white bagels as palate cleansers, consistent with AMSA (2016) sensory-evaluation guidelines and established methodology (Adhikari et al., 2011). Panelists were also provided with a specimen cup (expectorant cup), toothpicks, and reference solutions. Panelists were provided with attribute definitions and scale references during training and were allowed to refer to these materials as needed throughout evaluation. Muscles were evaluated separately to avoid direct comparisons among muscle types. Each muscle evaluation consisted of 10 sessions, with each panelist evaluating 8 samples per session, representing 1 sample from each aging duration, within a single muscle type. Samples were served in randomized order and evaluated immediately after preparation. Panelists were seated in individual sensory booths separated from the preparation area, with red lights used to minimize visual biases during evaluation. Session design and sample number were selected to balance panel efficiency and sensory discrimination while minimizing fatigue.
Steaks were thawed under refrigeration at approximately 4°C for up to 24 h prior to cooking. Steaks were cooked on a commercial flat-top grill set to 190.5°C. Internal temperatures were monitored using iron-constantan thermocouples (Omega Engineering, Stamford, CT) inserted into the geometric center of each steak. Steaks were flipped at an internal temperature of 35°C and removed at 71°C to ensure consistent final degree of doneness. Final internal temperatures were displayed using an Omega HH501BT Type T thermometer (Omega Engineering). Raw steak weights were recorded before grilling, and final cooked weights and temperatures were recorded upon removal from the grill. After cooking, steaks were trimmed of exterior fat and heavy connective tissue and cut into 1.3 × 1.3 × steak thickness cuboidal sections. Two cubes per sample were served in 2-oz translucent portion cups and identified with random 3-digit codes.
Instrumental color analysis
Instrumental color was evaluated at each aging duration interval using a Hunter EZ 45/0 LAV MiniScan spectrophotometer (2.5-cm aperture, illuminant A, 10° standard observer angle, HunterLab Associates, Reston, VA), following the AMSA guidelines for meat color measurement (King et al., 2023). Lean-color measurements were taken from the steak surface after a minimum bloom time of 30 min. The spectrophotometer was calibrated prior to use with a black and white tile to ensure accuracy. Color values were obtained from 3 different locations on the lean surface of each steak. The Commission Internationale de l’Éclairage L*, a*, b*, and spectral data from 400 nm to 700 nm were used to characterize surface color. The final color value for each steak was calculated as the mean of these 3 measurements.
L*, a*, and b* values were converted into XYZ hex codes, which were then transformed into red-green-blue (RGB) values as specified by Schwarz et al. in 1987. The RGB values, obtained for each muscle across all 8 aging durations, were used to create a visual color plot to illustrate the color changes over time.
Statistical analysis
All descriptive-sensory, pH, and color data were analyzed using R Studio statistical software (R Core Team, version 4.3.1), and the significance level was set at a α = 0.05 for all analyses. Linear mixed-effects models were fit for each response variable using lmer() function in the lme4 package in R (Bates et al., 2015), with aging duration included as a fixed effect and the collection date included as a random effect. Analysis of variance was performed on the fitted mixed model objects to assess the fixed effect of aging duration. When significant effects were detected, estimated marginal means were generated and separated using the emmeans() function in the emmeans package (Lenth, 2022). All analysis of variance models were built with the fixed effect of aging duration and a random effect of collection date. Estimated marginal means were calculated for all variables by fitting linear mixed effect models, using the lmer() function in the lme4 package in R Studio (Bates et al., 2015). The anova() function was then used (base R; R Core Team, 2022). Finally, estimated marginal means were calculated and tested for significance, using the emmeans() function in the emmeans package of R (Lenth, 2022).
Principal coordinate analysis (PCoA) was used to visualize the descriptive-sensory data. Bray-Curtis distance was calculated between all samples within each muscle using vegdist() function from the vegan package in R Studio (Oksanen et al., 2024). Using the distance matrix, PCoA were constructed using the pcoa() function from the Ape package in R Studio (Paradis and Schliep, 2019). Data points were colored by aging duration to identify any visual grouping patterns, and the top 10 sensory attributes were overlaid as vectors to aid interpretation of sample separation. Partial least-squares discriminant analyses (PLS-DA) were determined using the caret package in R Studio (Kuhn, 2008), with data ellipses colored by muscle to identify any visual grouping.
All consumer-sensory and shear-force data were analyzed using SAS (Version 9.4) PROC GLIMMIX, with aging duration as a fixed effect and panel session as a random effect. Steak peak temperature was used as a covariate. All acceptability data (yes/no) were analyzed using a model with binomial error distribution. Kenward-Roger adjustment was used for degrees of freedom. When the overall F test was significant, treatment means were separated using the pdiff option using α equal to 0.05.
Results and Discussion
pH
The estimated marginal means of pH levels for BF, GM, and SM were analyzed across 8 aging periods, as reported in Table 2. The data collected during each aging duration did not reveal differences in pH levels across the aging periods for each muscle (P ≥ .12). These results are congruent with Li et al. (2014) who evaluated pH in beef Longissimus aged for 8 and 19 d. The pH levels of the 3 muscles remained consistent across the aging periods (5.55–5.68), indicating that aging did not impact the muscle pH.
Estimated marginal means of whole muscle pH level of 3 beef muscles (Biceps femoris, Gluteus medius, and Semimembranosus) (n = 80) across 8 wet-aging periods
| Muscle | 14 d | 28 d | 35 d | 42 d | 49 d | 56 d | 63 d | 70 d | SEM1 | P Value |
|---|---|---|---|---|---|---|---|---|---|---|
| BF2 | 5.65 | 5.62 | 5.68 | 5.63 | 5.65 | 5.64 | 5.65 | 5.63 | 0.02 | .42 |
| GM3 | 5.62 | 5.58 | 5.63 | 5.62 | 5.58 | 5.72 | 5.61 | 5.60 | 0.06 | .61 |
| SM4 | 5.59 | 5.63 | 5.61 | 5.63 | 5.55 | 5.57 | 5.58 | 5.55 | 0.03 | .12 |
Abbreviations: BF, Biceps femoris; GM, Gluteus medius; IMPS, Institutional Meat Purchase Specifications; NAMP, North American Meat Processors Association; SEM, standard error of the means; SM, Semimembranosus.
Largest SEM.
Top sirloin butt subprimal (IMPS 184, NAMP 2014).
Top sirloin butt subprimal (IMPS 184, NAMP 2014).
Inside round subprimal (IMPS 168, NAMP 2014).
Consumer sensory
The demographic profile of all consumers is demonstrated in Table 3. Within the consumer panel, 53.5% were male and 46.5% were female. Most participants identified as Caucasian/white (86%). Additionally, most respondents were married (54%), 20 to 39 y old (55%), with some college or technical school education (44%). Consumers predominately purchased beef 2 to 6 times per week (72%) and preferred their beef cooked to a medium-rare degree of doneness, with flavor being the most import trait to 44% of consumers.
Demographic characteristics of consumers (N = 288) who participated in sensory panels
| Characteristic | Response | Percentage of Consumers (N = 288) |
|---|---|---|
| Gender | Male | 53.5 |
| Female | 46.5 | |
| Household size, people | 1 | 22.3 |
| 2 | 34.4 | |
| 3 | 11.0 | |
| 4 | 16.7 | |
| 5 | 8.1 | |
| 6 | 4.3 | |
| >6 | 0.2 | |
| Marital status | Married | 53.5 |
| Single | 46.5 | |
| Age, y | <20 | 6.4 |
| 20–29 | 37.9 | |
| 30–39 | 16.7 | |
| 40–49 | 8.2 | |
| 50–59 | 11.7 | |
| >60 | 19.1 | |
| Ethnic origin | African American | 2.5 |
| Asian | 1.1 | |
| Caucasian/white | 84.4 | |
| Latino | 3.9 | |
| Mixed race | 4.6 | |
| Other | 1.8 | |
| Annual household income level, $ | <25,000 | 22.3 |
| 25,000–34,999 | 6.7 | |
| 35,000–49,999 | 11.0 | |
| 50,000–74,999 | 13.1 | |
| 75,000–99,999 | 17.7 | |
| 100,000–149,999 | 13.8 | |
| 150,000–199,999 | 7.1 | |
| >199,999 | 8.2 | |
| Education level | Nonhigh school graduate | 0.4 |
| High school graduate | 16.3 | |
| Some college/technical school | 43.6 | |
| College graduate | 29.8 | |
| Postcollege graduate | 9.9 | |
| Most important beef palatability trait | Flavor | 47.5 |
| Tenderness | 38.3 | |
| Juiciness | 14.2 | |
| Most variable beef palatability trait | Flavor | 31.6 |
| Tenderness | 42.6 | |
| Juiciness | 25.9 | |
| Degree of doneness preference | Very rare | 1.1 |
| Rare | 7.1 | |
| Medium-rare | 55.3 | |
| Medium | 21.3 | |
| Medium-well | 10.3 | |
| Well-done | 4.3 | |
| Very well-done | 0.01 | |
| Times beef consumed per week | 0 | 0.0 |
| 1–3 | 22.7 | |
| 4–6 | 33.0 | |
| 7–9 | 10.6 | |
| ≥10 | 11.3 |
Consumer-liking results are presented in Table 4. There were no differences in flavor and juiciness liking across all 8 aging durations for all 3 muscles (P ≥ .06). Moreover, BF and GM steaks also exhibited similar overall and tenderness liking values across all 8 aging durations (P ≥ .09). The SM steaks aged for 56 d were rated greater for overall liking when compared to 28-, 49-, 63-, and 70-d aged SM steaks (P < .05). Additionally, 14-d aged SM steaks were rated the lowest for overall liking (P < .05). When evaluated for tenderness liking, 56-d aged SM steaks were also rated more tender than all other aging durations (P < .05), whereas consumers rated 14-d aged SM steaks the toughest (P < .05).
Least-squares means for consumer (N = 288) sensory ratings1 for flavor, juiciness, tenderness, and overall liking and Warner-Bratzler shear force of beef Biceps femoris, Gluteus medius, and Semimembranosus steaks from wet-aged subprimals for 7 wet-aging periods
| Characteristics | 14 d | 28 d | 35 d | 42 d | 49 d | 56 d | 63 d | 70 d | SEM2 | P Value |
|---|---|---|---|---|---|---|---|---|---|---|
| BF3 | ||||||||||
| WBSF | 3.85 | 3.13 | 3.35 | 3.35 | 3.31 | 3.33 | 3.53 | 3.68 | 0.25 | .52 |
| Overall liking | 6.6 | 6.7 | 6.8 | 6.9 | 6.0 | 7.0 | 6.5 | 6.3 | 0.30 | .21 |
| Flavor liking | 6.0 | 6.5 | 6.3 | 6.3 | 5.7 | 6.6 | 5.9 | 5.4 | 0.33 | .09 |
| Juiciness liking | 6.6 | 6.8 | 6.7 | 7.3 | 6.6 | 7.5 | 6.7 | 6.4 | 0.35 | .36 |
| Tenderness liking | 6.2 | 7.0 | 6.4 | 7.1 | 6.1 | 7.2 | 6.6 | 6.1 | 0.35 | .14 |
| GM4 | ||||||||||
| WBSF | 4.25a | 3.57bc | 3.69b | 3.43bc | 3.28b–d | 2.89d | 3.09cd | 2.86d | 0.18 | <.01 |
| Overall liking | 5.9 | 6.0 | 6.3 | 6.7 | 6.2 | 6.7 | 6.5 | 6.2 | 0.35 | .29 |
| Flavor liking | 5.9 | 5.6 | 6.2 | 6.2 | 5.9 | 6.5 | 6.1 | 5.9 | 0.41 | .59 |
| Juiciness liking | 5.8 | 5.4 | 5.8 | 6.4 | 5.9 | 6.4 | 5.7 | 5.5 | 0.36 | .30 |
| Tenderness liking | 5.7 | 5.6 | 5.8 | 6.4 | 6.3 | 6.7 | 6.4 | 6.4 | 0.44 | .32 |
| SM5 | ||||||||||
| WBSF | 4.77a | 3.61c | 4.47ab | 3.89bc | 3.68bc | 3.33c | 3.34c | 3.80bc | 0.29 | <.01 |
| Overall liking | 4.7c | 6.0ab | 5.3bc | 5.2bc | 5.7a–c | 6.4a | 5.7a–c | 6.1bc | 0.39 | .04 |
| Flavor liking | 4.7 | 5.7 | 4.8 | 4.9 | 5.3 | 5.9 | 5.4 | 5.8 | 0.37 | .07 |
| Juiciness liking | 4.6 | 5.9 | 4.9 | 5.2 | 5.2 | 6.5 | 5.7 | 5.6 | 0.44 | .06 |
| Tenderness liking | 3.7c | 5.2ab | 4.5bc | 4.8bc | 5.0a–c | 6.2a | 5.5ab | 5.7ab | 0.50 | .02 |
Abbreviations: BF, Biceps femoris; GM, Gluteus medius; IMPS, Institutional Meat Purchase Specifications; NAMP, North American Meat Processors Association; SEM, standard error of the means; SM, Semimembranosus; WBSF, Warner-Bratzler shear force.
Sensory scores: 0 = dislike extremely; 10 = like extremely.
SEM (largest) of the least-square means.
Top sirloin butt subprimal (IMPS 184, NAMP 2014).
Top sirloin butt subprimal (IMPS 184, NAMP 2014).
Inside round subprimal (IMPS 168, NAMP 2014).
Least-squares means in the same column within a muscle without a common superscript differ (P < .05).
The percentage of samples rated acceptable for overall, flavor, juiciness, and tenderness are illustrated in Table 5. Acceptability was similar (P ≥ .31) across all aging durations for overall, flavor, juiciness, and tenderness of BF and GM steaks. However, SM steaks had a greater (P = .02) percentage of steaks aged 56 d rated acceptable overall compared to steaks aged 14, 42, and 70 d. Additionally, consumers had a greater percentage of samples rated acceptable for juiciness for SM steaks aged 28, 56, and 63 d compared to all other aging durations. Moreover, 14-d aged SM steaks had the lowest percentage of samples rated acceptable when compared to all other aging durations (P < .05). The SM steaks aged 70 d had the greatest percentage of samples rated acceptable for tenderness compared to steaks aged 14, 28, 35, 42, and 49 d (P < .05). Additionally, 14-d aged SM steaks were the least accepted by consumers for overall tenderness (P < .05).
Least-squares means for the percentage of beef Biceps femoris, Gluteus medius, and Semimembranosus steaks from wet-aged subprimals rated as acceptable by consumers (N = 288) for 8 wet-aging periods
| Characteristics | 14 d | 28 d | 35 d | 42 d | 49 d | 56 d | 63 d | 70 d | SEM1 | P Value |
|---|---|---|---|---|---|---|---|---|---|---|
| BF2 | ||||||||||
| Overall | 93.8 | 95.2 | 92.6 | 95.6 | 92.5 | 95.1 | 91.0 | 93.3 | 3.8 | .98 |
| Flavor | 94.2 | 95.1 | 89.9 | 93.6 | 87.5 | 96.8 | 90.6 | 94.2 | 5.2 | .36 |
| Juiciness | 96.1 | 89.1 | 92.7 | 98.8 | 98.7 | 96.3 | 92.5 | 94.4 | 4.7 | .36 |
| Tenderness | 89.5 | 95.2 | 91.6 | 91.1 | 86.0 | 95.4 | 91.0 | 92.2 | 5.0 | .71 |
| GM3 | ||||||||||
| Overall | 83.0 | 86.9 | 87.6 | 89.6 | 83.2 | 92.6 | 93.6 | 90.7 | 5.3 | .51 |
| Flavor | 87.1 | 76.5 | 88.2 | 91.4 | 82.0 | 88.3 | 89.4 | 85.3 | 4.9 | .41 |
| Juiciness | 78.8 | 70.7 | 85.9 | 81.8 | 76.2 | 90.3 | 82.7 | 79.2 | 4.4 | .31 |
| Tenderness | 84.3 | 84.6 | 75.4 | 87.3 | 83.1 | 92.5 | 91.8 | 83.3 | 5.5 | .33 |
| SM4 | ||||||||||
| Overall | 61.3c | 85.4ab | 79.9ab | 71.5bc | 82.5ab | 91.4a | 77.4a–c | 76.3bc | 4.8 | .02 |
| Flavor | 69.9 | 83.9 | 72.4 | 67.6 | 80.5 | 79.6 | 76.6 | 76.5 | 3.7 | .51 |
| Juiciness | 60.6b | 84.4a | 62.8b | 72.5ab | 74.9ab | 86.8a | 82.9a | 76.5ab | 4.2 | .02 |
| Tenderness | 50.7d | 67.2b–d | 66.7b–d | 60.8cd | 69.5a–d | 57.1ab | 72.9a–c | 83.8a | 3.0 | .01 |
BF, Biceps femoris; GM, Gluteus medius; IMPS, Institutional Meat Purchase Specifications; NAMP, North American Meat Processors Association; SEM, standard error of the means; SM, Semimembranosus.
SEM (largest) of the least-square means.
Top sirloin butt subprimal (IMPS 184, NAMP 2014).
Top sirloin butt subprimal (IMPS 184, NAMP 2014).
Inside round subprimal (IMPS 168, NAMP 2014).
Least-squares means in the same column within a muscle without a common superscript differ (P < .05).
Consumer-sensory evaluations highlight the consumer acceptance for beef-quality traits. Across the 8 aging durations, flavor, and juiciness liking showed no differences, for all 3 muscles, suggesting that aging beyond 14 d did not substantially impact these attributes. Overall, flavor plays an important role in consumer liking for beef (Killinger et al., 2004; Miller, 2020; O’Quinn et al., 2024). The differences shown in consumer acceptability for the SM steaks indicate that extended aging may enhance consumer-perceived tenderness and overall acceptability. The increased tenderness acceptability observed at 56 d of aging in the present study may be attributed to prolonged postmortem proteolytic activity, in which endogenous enzymes degrade key myofibrillar and cytoskeletal proteins, weakening muscle structure and improving tenderness (Ha et al., 2019; Hernandez et al., 2022). With tenderness as a major driver of consumer eating acceptability, this structural breakdown may have contributed to the greater consumer acceptance observed for SM steaks at longer aging durations. In contrast, the percentages of samples considered acceptable for overall liking, flavor, juiciness, and tenderness attributes maintained similar for the BF and GM steaks, which suggests that these muscles may not require extended aging to achieve optimal consumer satisfaction. Previous literature supports that extended wet-aging duration, typically 21 to 28 d, have shown to improve scores in consumer evaluations for tenderness and juiciness when compared to beef aged less than 21 d (Laster et al., 2008). Still, the lack of impact across all 8 aging durations on consumer acceptability of the BF and GM agrees with the findings of Smith et al. (2014).
Warner-Bratzler shear force
WBSF values are presented in Table 4. WBSF was similar (P = .52) across aging treatments for BF steaks, with all mean values of 3.85 kg or less. With the GM, 14-d steaks had the greatest WBSF value compared to all other aging durations (P ≤ .01). Moreover, GM steaks aged 28, 35, and 42 d had increased WBSF values compared to steaks aged 56 and 70 d (P < .05). At 14 d of age, SM steaks had the greatest WBSF value compared to 28, 42, 49, 56, 63, and 70 d (P < .05). SM steaks aged for 35 d had a greater WBSF value compared to steaks aged for 28, 63, and 70 d (P < .05).
Despite the wealth of literature supporting the tenderization of beef through postmortem aging, the results of the present study reveal discrepancies that challenge this widely accepted phenomenon. This divergence can be attributed to the focus on beef cuts outside of the Longissimus lumborum, a muscle often highlighted in tenderness research due to its inherently favorable qualities. The results of this study indicate that aging has limited effects on some muscles, such as the BF, which exhibit consistent tenderness across all aging durations. The present study agrees with the findings of Gruber et al. (2006), where Select BF and SM muscles did not improve past 21 d postmortem aging and the work of Smith et al. (1978) that found WBSF values to not improve after 11 d postmortem aging in USDA Choice BF muscles. This supports the notion that some muscles may not benefit significantly from extended aging due to their intrinsic characteristics, such as lower connective-tissue content. It is understood that postmortem proteolysis and the presence of intramuscular lipids play a direct role in influencing the perception of meat tenderness (Lonergan et al., 2001). Conversely, muscles like the SM, which are more structurally complex, demonstrated greater variability in tenderness across aging durations. Rhee et al. (2004) reported the BF to have twice as much collagen as the GM. Furthermore, the BF WBSF tenderness values in comparison to SM findings may be due to the lower amount of connective tissue known to be present in the SM (Thompson, 2002; Colle et al., 2016). These findings reinforce the importance of tailoring aging practices to specific muscle groups, particularly for tougher, less frequently studied cuts. While the current literature predominantly focuses on middle meats, expanding research to include secondary cuts is crucial for maximizing the value and marketability of the entire carcass. Although recent literature has shown that flavor is the most important factor for consumers, tenderness remains a critical factor in determining beef palatability and consumer satisfaction (Miller et al., 1995; Huffman et al., 1996; Egan et al., 2001; Hammond et al., 2022; O’Quinn et al., 2024). Consequently, tenderness improvement has long been a priority for the meat industry. However, as reported in the 2017 Beef Tenderness Survey, approximately 95% of middle meats are already perceived as tender or very tender by consumers (Martinez et al., 2017). This raises questions about the diminishing returns of traditional postmortem aging strategies for muscles that naturally fall outside the middle meat category, such as the BF, GM, and SM.
Descriptive sensory
Biceps femoris
Descriptive-sensory data for the BF are presented in Table 6. Muscle-fiber tenderness, connective tissue, juiciness, browned/roasted, bloody/serumy, fat-like, metallic, salty, painty, burnt, and heated oil flavor attributes did not show comparable differences throughout aging durations (P ≥ .08).
Beef Biceps femoris1 least-square means of trained descriptive-sensory attributes2 across 8 wet-aging periods (n = 10)
| Attribute | 14 d | 28 d | 35 d | 42 d | 49 d | 56 d | 63 d | 70 d | SEM3 | P Value |
|---|---|---|---|---|---|---|---|---|---|---|
| Muscle-fiber tenderness | 8.9 | 9.5 | 8.4 | 8.7 | 8.6 | 9.1 | 9.0 | 8.8 | 0.38 | .18 |
| Connective tissue | 8.5 | 9.5 | 8.3 | 8.6 | 8.7 | 9.1 | 8.9 | 9.0 | 0.37 | .30 |
| Juiciness | 7.9 | 8.3 | 7.6 | 7.5 | 7.8 | 7.8 | 7.4 | 7.3 | 0.27 | .16 |
| Beef ID | 8.8a | 8.6ab | 8.6ab | 8.7ab | 8.6ab | 8.8a | 8.4bc | 8.2c | 0.13 | .01 |
| Browned/roasted | 8.4 | 8.5 | 8.3 | 8.4 | 8.4 | 9.0 | 8.3 | 8.5 | 0.31 | .42 |
| Bloody/serumy | 1.9 | 2.2 | 1.7 | 1.6 | 2.0 | 1.7 | 1.4 | 1.3 | 0.29 | .25 |
| Fat | 3.5 | 3.7 | 3.0 | 3.3 | 3.2 | 3.5 | 3.4 | 3.3 | 0.28 | .08 |
| Metallic | 0.9 | 1.1 | 1.2 | 1.2 | 1.2 | 1.0 | 1.3 | 1.2 | 0.2 | .80 |
| Liver | 1.3ab | 0.8a | 1.3ab | 1.0a | 1.3ab | 1.2ab | 2.9c | 1.9bc | 0.27 | <.01 |
| Bitter | 0.6ab | 0.6a | 1.0a–d | 0.8ab | 0.9a–c | 1.1b–d | 1.3d | 1.3cd | 0.24 | <.01 |
| Salty | 0.4 | 0.4 | 0.5 | 0.3 | 0.5 | 0.5 | 0.3 | 0.3 | 0.13 | .74 |
| Sweet | 0.6ab | 0.7a | 0.2cd | 0.4b–d | 0.2cd | 0.4a–c | 0.1d | 0.2cd | 0.11 | <.01 |
| Sour | 0.7a | 0.8a | 0.6a | 0.8a | 0.8a | 0.8a | 1.3b | 1.4b | 0.19 | .01 |
| Umami | 8.4a | 8.4a | 8.3ab | 8.2ab | 8.0ab | 8.4a | 8.0b | 7.9b | 0.16 | .02 |
| Musty | 1.6a | 1.4a | 1.8a | 1.7a | 1.6a | 1.7a | 2.6b | 2.4b | 0.22 | <.01 |
| Cardboardy | 0.3a | 0.3a | 0.5ab | 0.5ab | 0.5ab | 0.4ab | 0.7bc | 0.9c | 0.14 | <.01 |
| Painty | 0.1 | 0.1 | 0.1 | 0.1 | 0.2 | 0.2 | 0.4 | 0.3 | 0.08 | .08 |
| Burnt | 0.2 | 0.3 | 0.4 | 0.2 | 0.6 | 0.6 | 0.4 | 0.4 | 0.31 | .58 |
| Heated oil | 0.1 | 0.1 | 0.0 | 0.1 | 0.1 | 0.0 | 0.1 | 0.1 | 0.05 | .71 |
| Buttery | 0.3a–c | 0.5a | 0.2bd | 0.2b–d | 0.3b–d | 0.5ac | 0.1bd | 0.1d | 0.10 | <.01 |
Abbreviations: ID, identification; IMPS, Institutional Meat Purchase Specifications; NAMP, North American Meat Processors Association; SEM, standard error of the means.
Top sirloin butt subprimal (IMPS 184, NAMP 2014).
Trained sensory scores: 0 = extremely dry/tough/not detectable, 15 = extremely juicy/tender/extremely detectable.
Largest SEM of the least-squares means, using Kenward-Rogers degrees of freedom proximation.
Least-square means in the same row without a common superscript differ (P < .05).
Generally, as aging duration increased, the BF flavor profile changed, particularly concerning beef-flavor identity and the presence of certain off-flavors. Beef-flavor identity exhibited differences throughout aging duration (P = .01). Specifically, decreased intensities were noted at 63- and 70-d durations when compared to 14- and 56-d durations (P < .05). However, the intensity means were considered to be moderately intense regardless of aging duration (AMSA, 2016). Buttery expressed differences across aging durations (P < .01), with decreased intensities reported at 63- and 70-d aging durations relative to 28- and 56-d aging durations (P < .05). Similar to beef-flavor identity, buttery means did not show drastic changes and were considered to be not detectable.
Generally, as aging duration increased, off-flavor intensity increased. Specifically, liver-like had notable differences, identified as barely detectable (P < .01), with greater intensities shown at 63 d, compared to 14, 28, 35, 42, 49, and 56 d (P < .05). Additionally, bitter basic taste expressed differences across aging durations (P < .01), with greater intensities present at 63- and 70-d aging durations, relative to 14-, 28-, and 42-d aging durations (P < .05). Moreover, musty/earthy/humus intensity showed an increase across aging durations, identified as barely detectable (P < .01). Musty/earthy/humus intensity increased at 63 d, when compared to all other aging durations (P < .05). Similarly, cardboardy showed differences across aging durations (P < .01), with increased intensities were exhibited at 70-d aging duration, relative to 14-, 28-, 35-,42-, 49- and 56-d aging durations (P < .05). Sour basic taste increased as aging duration increased (P = .01), where intensity increased at 63 d when compared to 14-, 28-, 35-, 42-, 49-, and 56-d durations. In contrast, the sweet basic taste attribute showed differences across aging durations (P < .01), with the inverse trend expressing less intensity at 63 and 70 d when evaluated alongside 14- and 28-d aging durations (P < .05). Furthermore, umami basic taste showed intensity differences across aging durations (P = .02), with less intensity reported at 63 and 70 d, relative to 14-, 28-, 35-, 42-, 49-, and 56-d aging durations.
Gluteus medius
Descriptive-sensory data for the GM is found in Table 7. Juiciness, browned/roasted, bloody/serumy, fat-like, salty, sweet, burnt, and buttery flavor attributes did not exhibit comparable differences throughout aging durations (P ≥ .08).
Beef Gluteus medius1 least-square means of trained descriptive-sensory attributes2 across 8 aging periods (n = 10)
| Attribute | 14 d | 28 d | 35 d | 42 d | 49 d | 56 d | 63 d | 70 d | SEM3 | P Value |
|---|---|---|---|---|---|---|---|---|---|---|
| Muscle-fiber tenderness | 7.9ab | 8.6c | 7.8a | 8.8c | 8.6bc | 8.8c | 9.2c | 8.9c | 0.29 | <.01 |
| Connective tissue | 7.5ab | 8.1ac | 7.3b | 8.1ac | 7.9a–c | 8.5c | 8.6c | 8.5c | 0.32 | <.01 |
| Juiciness | 7.5 | 7.5 | 7.2 | 7.5 | 7.0 | 7.1 | 7.2 | 7.3 | 0.27 | .77 |
| Beef ID | 8.7a | 8.6ab | 8.4a–c | 8.3b–d | 8.2b–d | 8.1c–e | 7.8e | 8.0de | 0.14 | <.01 |
| Browned/roasted | 8.7 | 8.7 | 8.6 | 8.5 | 8.4 | 8.5 | 8.3 | 8.2 | 0.16 | .26 |
| Bloody/serumy | 1.1 | 1.6 | 1.1 | 1.2 | 1.2 | 0.9 | 1.0 | 1.3 | 0.22 | .47 |
| Fat | 2.6 | 2.6 | 2.4 | 2.5 | 2.2 | 2.4 | 2.4 | 2.4 | 0.28 | .15 |
| Metallic | 1.0a | 1.3a–c | 1.1ab | 1.1ab | 1.2ab | 1.1ab | 1.6c | 1.4bc | 0.13 | <.01 |
| Liver | 0.7a | 0.8a | 0.7a | 0.7a | 0.9a | 0.9a | 1.7b | 1.0a | 0.20 | .01 |
| Bitter | 0.5a | 0.6a | 0.6a | 0.5a | 0.7a | 0.8a | 1.3b | 0.8a | 0.13 | <.01 |
| Salty | 0.8 | 0.6 | 0.6 | 0.6 | 0.5 | 0.5 | 0.4 | 0.4 | 0.11 | .08 |
| Sweet | 0.4 | 0.4 | 0.4 | 0.3 | 0.2 | 0.5 | 0.1 | 0.2 | 0.14 | .25 |
| Sour | 0.5a | 1.0b | 0.9ab | 1.0ab | 1.3bc | 1.1b | 2.2d | 1.6c | 0.17 | <.01 |
| Umami | 8.5a | 8.4ab | 8.4ab | 8.3ab | 8.2a–c | 8.1b–d | 7.8d | 8.0cd | 0.21 | <.01 |
| Musty | 1.1a | 1.5ab | 1.5ab | 1.4ab | 1.5ab | 1.6bc | 2.0c | 1.8bc | 0.26 | <.01 |
| Cardboardy | 0.7a | 0.7a | 0.8a | 0.8a | 0.9a | 1.0a | 1.3b | 0.8a | 0.18 | <.01 |
| Painty | 0.0a | 0.3ab | 0.2ab | 0.1a | 0.2ab | 0.2ab | 0.7c | 0.4b | 0.11 | <.01 |
| Burnt | 0.4 | 0.1 | 0.4 | 0.3 | 0.3 | 0.5 | 0.4 | 0.2 | 0.13 | .67 |
| Heated oil | 0.2a–c | 0.2ab | 0.3a | 0.1bc | 0.0c | 0.1c | 0.0c | 0.0c | 0.06 | <.01 |
| Buttery | 0.1 | 0.0 | 0.0 | 0.1 | 0.0 | 0.0 | 0.1 | 0.1 | 0.04 | .81 |
Abbreviations: ID, identification; IMPS, Institutional Meat Purchase Specifications; NAMP, North American Meat Processors Association; SEM, standard error of the means.
Top sirloin butt subprimal (IMPS 184, NAMP 2014).
Trained sensory scores: 0 = extremely dry/tough/not detectable, 15 = extremely juicy/tender/extremely detectable.
Largest SEM of the least-squares means, using Kenward-Rogers degrees of freedom proximation.
Least-square means in the same row without a common superscript differ (P < .05).
Generally, as aging duration increased, GM steaks exhibited greater muscle-fiber tenderness and reduced connective-tissue values (P < .01) at 35 d of aging when compared to 28, 42, 49, 56, 63, and 70 d of aging, ranging from slightly tender to moderately tender (P < .05). Connective-tissue values generally increased with increased aging duration, as shown by decreased connective-tissue presence at 56-, 63-, and 70-d aging durations when compared to 14-, 28-, 35-, and 42-d aged steaks (P < .05), identified as slightly detectable to moderately detectable. Similarly, beef-flavor identity intensity followed a similar reduction across all 8 aging durations (P < .01). Comparatively, 63-d aged steaks possessed decreased beef-flavor identity, compared to 14-, 28-, 35-, 42-, and 49-d aged steaks (P < .05), identified verbally as moderately intense. Umami also showed a comparable reduction in intensity throughout all 8 aging durations (P < .01). Specifically, reporting decreased intensity values at 63 d duration when compared to 14-, 28-, 35-, 42-, and 49-d aged steaks (P < .05). However, the intensity means were moderately intense regardless of aging duration. Precisely, metallic differences were detectable throughout all 8 aging durations (P < .01). Notable differences in metallic intensity were shown by increased intensity at 63-d duration in contrast to less intensity exhibited at 14-, 35-, 42-, 49-, and 56-d aging durations (P < .05). Similar to umami, metallic intensity means did not show large changes and were not detectable. Additionally, liver-like showed differences throughout all 8 aging durations (P = .01). Liver-like intensities reported increased intensity at 63-d aging duration as opposed to decreased intensities at 14-, 28-, 35-, 42-, 49-, 56-, and 70-d aging durations (P < .05). Moreover, bitter intensities across all 8 aging durations expressed differences (P < .01), with greater intensity displayed at 63 d of aging when compared alongside 14-, 28-, 35-, 42-, 49-, 56-, and 70-d aging durations (P < .05). Similarly, sour flavor attributes exhibited differences throughout aging durations (P < .01), identified as not detectable or barely detectable. Sour intensity was reported greatest at 63 d of aging, relative to decreased intensities exhibited at all other aging durations (P < .05). The musty/earthy/humus attribute showed intensity differences throughout aging durations (P < .01), with greater intensity at 63-d aged when compared to 14-, 28-, 35-, 42-, and 49-d aging durations (P < .05) and recognized as not detectable or barely detectable. Moreover, cardboardy also reported differences throughout aging durations (P < .01), with greater expressed intensity at 63 d in comparison to less intensity indicated at all other aging durations (P < .05). Additionally, painty followed a similar increase throughout aging durations (P < .01), with the greatest intensity shown at 63-d duration when compared to all other aging durations (P < .05). Finally, heated oil expressed a general reduction of intensity across aging durations (P < .01). Decreased heated oil intensity was presented at 49-, 56-, 63-, and 70-d aging durations in comparison to greater intensity reported at 14-, 28-, and 35-d aging durations (P < .05).
Semimembranosus
Descriptive-sensory data for the SM are presented in Table 8. Muscle-fiber tenderness and connective tissue did not exhibit differences throughout aging durations (P ≥ .06). Moreover, juiciness, beef identity, browned/roasted, bloody/serumy, fat-like, metallic, liver-like, salty, sweet, sour, umami, painty, burnt, heated oil, and buttery flavor attributes did not have intensity differences across aging durations (P ≥ .07).
Beef Semimembranosus1 least-square means of trained descriptive-sensory attributes2 across 8 aging periods (n = 10)
| Attribute | 14 d | 28 d | 35 d | 42 d | 49 d | 56 d | 63 d | 70 d | SEM3 | P Value |
|---|---|---|---|---|---|---|---|---|---|---|
| Muscle-fiber tenderness | 7.8 | 7.8 | 8.0 | 8.5 | 8.2 | 8.4 | 8.2 | 8.3 | 0.23 | .19 |
| Connective tissue | 7.5 | 7.2 | 7.6 | 8.1 | 7.9 | 8.0 | 7.7 | 7.8 | 0.22 | .06 |
| Juiciness | 7.3 | 7.1 | 7.3 | 7.1 | 7.4 | 7.5 | 7.6 | 7.1 | 0.19 | .35 |
| Beef ID | 8.1 | 7.9 | 7.9 | 7.8 | 7.9 | 7.9 | 7.9 | 7.8 | 0.12 | .50 |
| Browned/roasted | 8.1 | 8.2 | 8.0 | 8.1 | 8.1 | 8.2 | 8.1 | 8.0 | 0.12 | .64 |
| Bloody/serumy | 1.2 | 1.2 | 1.3 | 1.0 | 1.2 | 1.2 | 1.3 | 0.9 | 0.17 | .54 |
| Fat | 2.1 | 2.0 | 2.2 | 2.0 | 2.0 | 2.1 | 2.1 | 2.0 | 0.14 | .47 |
| Metallic | 0.8 | 1.1 | 1.1 | 0.9 | 1.2 | 0.9 | 1.2 | 1.0 | 0.11 | .07 |
| Liver | 0.4 | 0.7 | 0.8 | 0.5 | 0.8 | 0.7 | 0.9 | 0.7 | 0.17 | .44 |
| Bitter | 0.5ab | 0.7a–c | 0.7a–c | 0.5a | 0.9c | 0.7a–c | 0.9c | 0.8bc | 0.13 | .02 |
| Salty | 0.5 | 0.6 | 0.4 | 0.6 | 0.5 | 0.5 | 0.6 | 0.5 | 0.08 | .35 |
| Sweet | 0.5 | 0.3 | 0.3 | 0.4 | 0.3 | 0.4 | 0.3 | 0.2 | 0.09 | .56 |
| Sour | 0.8 | 1.1 | 1.0 | 0.9 | 1.3 | 1.0 | 1.2 | 1.1 | 0.13 | .15 |
| Umami | 7.8 | 7.9 | 7.9 | 7.9 | 7.8 | 8.0 | 7.9 | 7.8 | 0.15 | .98 |
| Musty | 1.0 | 1.3 | 1.5 | 1.2 | 1.7 | 1.5 | 1.4 | 1.3 | 0.20 | .08 |
| Cardboardy | 0.6a | 0.9bc | 0.7ab | 0.9bc | 1.0c | 1.0c | 0.9bc | 0.9bc | 0.09 | .01 |
| Painty | 0.1 | 0.2 | 0.2 | 0.2 | 0.3 | 0.1 | 0.3 | 0.2 | 0.08 | .09 |
| Burnt | 0.1 | 0.1 | 0.1 | 0.1 | 0.2 | 0.3 | 0.3 | 0.3 | 0.08 | .18 |
| Heated oil | 0.2 | 0.1 | 0.0 | 0.1 | 0.1 | 0.1 | 0.0 | 0.0 | 0.06 | .16 |
| Buttery | 0.1 | 0.0 | 0.0 | 0.1 | 0.0 | 0.0 | 0.1 | 0.1 | 0.04 | .60 |
Abbreviations: ID, identification; IMPS, Institutional Meat Purchase Specifications; NAMP, North American Meat Processors Association; SEM, standard error of the means.
Inside round subprimal (IMPS 168, NAMP 2014).
Trained sensory scores: 0 = extremely dry/tough/not detectable, 15 = extremely juicy/tender/extremely detectable.
Largest SEM of the least-squares means, using Kenward-Rogers degrees of freedom proximation.
Least-square means in the same row without a common superscript differ (P < .05).
As aging duration increased, the SM flavor profile generally changed, specifically, reporting cardboardy and bitter. Cardboardy flavor attribute showed differences across aging durations (P = .01), with greater intensities shown at 49 and 56 d aging, relative to 14- and 35-d aging durations (P < .05), identifying as generally not detectable. Moreover, bitter showed differences in intensities across aging duration (P = .02), where greater intensity was reported at 49- and 63-d aging durations compared to 14- and 42-d aging durations and was considered to be not detectable across aging durations.
PCoA of BF, GM, and SM are shown in Figures 1 to 3. Additionally, a PLS-DA was performed to distinguish sensory attributes among 3 different beef muscles (Figure 4). The score plot utilized 2 components, which captured the variance in the sensory data collected by trained descriptive panelists and demonstrated discrimination among the muscle types. The PLS-DA score plot illustrates the separation between the muscle groups. Each group forms clusters, indicating that the sensory attributes are different among these muscles.
Principal coordinate analysis of trained descriptive-sensory panel ratings for Biceps femoris steaks across 8 wet-aging durations. Individual observations are shown as points, and ellipses represent the 95% CI for each aging duration. Vectors represent the direction and relative contribution of the top 10 sensory attributes based on vector magnitude. Numeric labels correspond to the following: 1 = muscle-fiber tenderness, 2 = musty/earthy/humus, 3 = liver-like, 4 = sweet, 5 = connective tissue, 6 = juiciness, 7 = sour, 8 = bloody/serumy, 9 = cardboardy, and 10 = umami. Abbreviation: PC, principal coordinate.
Principal coordinate analysis of trained sensory panel ratings for Gluteus medius steaks across aging durations. Individual observations are shown as points, and ellipses represent the 95% CI for each aging duration. Vectors represent the direction and relative contribution of the top 10 sensory attributes based on vector magnitude. Numeric labels correspond to the following: 1 = juiciness, 2 = bloody/serumy, 3 = muscle-fiber tenderness, 4 = bitter, 5 = sour, 6 = connective tissue, 7 = beef-flavor identity, 8 = musty, 9 = liver, and 10 = umami. Abbreviation: PC, principal coordinate.
Principal coordinate analysis of trained sensory panel ratings for Semimembranosus steaks across aging durations. Points represent individual observations, and ellipses denote the 95% CI for each aging duration. Vectors represent the direction and relative contribution of the top 10 sensory attributes based on vector magnitude. Numeric labels correspond to the following: 1 = juiciness, 2 = sour, 3 = muscle-fiber tenderness, 4 = musty, 5 = connective tissue, 6 = bloody/serumy, 7 = liver, 8 = beef-flavor identity, 9 = umami, and 10 = bitter. Abbreviation: PC, principal coordinate.
Visualization of the partial least-squares discriminant analysis of beef Biceps femoris, Gluteus medius and Semimembranosus as determined by trained descriptive-sensory panelists. Abbreviations: BF, Biceps femoris; GM, Gluteus medius; PLS-DA, partial least-squares discriminant analysis; SM, Semimembranosus.
The BF cluster is positioned predominantly in the lower-left quadrant, separated from GM and SM, which overlap to some extent but still maintain groupings. The ellipses surrounding each cluster represent the 95% CI, highlighting the within-group variability and the overall discrimination between the muscle types. These results suggest that the sensory profiles vary among the muscles, with the PLS-DA Figure 4 score plot effectively differentiating the groups based on their unique attributes.
The present study demonstrates muscle-specific changes in beef-flavor profile across aging durations. Extended-aged product is known to produce off-flavors, such as sour, oxidized, liver-like, metallic, and musty/earthy while decreasing beef-flavor identity (O’Quinn et al., 2016; Evers et al., 2020; Foraker et al., 2020; Hernandez et al., 2023). These reports have highlighted lipid oxidation and microbial growth as drivers of off-flavor development in wet-aged products. The increase in off-flavors observed with extended-aging durations in the present study aligns with previous research, indicating that oxidative reactions and spoilage-associated changes often contribute to negative flavor development (Dinh et al., 2021). Moreover, previous reports have suggested that the reduction in positive flavor attributes, such as beef-flavor identity across aging durations in all 3 muscles, reflects the interaction between lipid degradation and the Maillard reaction (Bekhit et al., 2013; Vierck et al., 2020). The progressive decline in antioxidant potential during postmortem storage may also contribute to the damage of biological molecules in postmortem muscle as a result of reactive oxygen species (Théron and Estévez, 2022). Hernandez et al. (2022) reported an increase in spoilage organism growth as aging duration increased, especially when aging temperature was held at 4°C. These results were aligned with increased off-flavors (liver-like, musty/earthy, sour, and bitter; Hernandez et al., 2023). Therefore, it is likely that microbial growth played a role in off-flavor development in the present study. Additionally, purge accumulation and package-related odors may have contributed to sensory perception under extended vacuum-package aging conditions, although those variables were not directly measured in the present study. The increases in bitter and sour basic tastes are also likely a function of free amino acid accumulation, which has been reported to increase throughout the aging process (Koutsidis et al., 2008; Foraker et al., 2020; Hernandez et al., 2022). Foraker et al. (2020) reported positive, strong correlations between sour basic taste and alanine, aspartic acid, phenylalanine, and tyrosine, which all contribute to sour basic taste (Dashdorj et al., 2015).
While differences were observed in the descriptive-sensory data, the magnitude changes were marginal. These results are likely a function of the colder storage temperature and the absence of “leakers” in the study. Hernandez et al. (2023) demonstrated that storage of beef-strip loins at −2°C and 0°C reduced off-flavor development via reduced microbial growth. Moreover, the anaerobic nature of vacuum packaging is inherently protective of beef, as it inhibits the progression of lipid oxidation and subsequent quality deterioration.
Additionally, with tenderness playing a critical role in consumer satisfaction for beef, there are industry strategies aimed at optimizing tenderness of beef muscles. Postmortem aging is the simplest and most effective method to develop tenderness, especially when aged beyond 14 d (Martinez et al., 2017). Previous reports have shown that ultimate tenderness is often developed by 42 d (Lepper-Blilie et al., 2016; Hernandez et al., 2022). King et al. (2021) reported a general increase in overall tenderness of Longissimus lumborum and GM steaks, but reports that postmortem storage of the BF steaks showed reduced tenderness intensities with prolonged aging durations. The current study agrees with these works, relative to all 3 muscles.
Objective color analysis
Estimated marginal means of L*, a*, b*, hue, and chroma of BF, GM, and SM are shown in Table 9.
Estimated marginal means of L*, a*, and b* evaluated using Hunter MiniScan on 3 beef muscles (Biceps femoris, Gluteus medius, and Semimembranosus) (N = 80, n = 10) across 8 wet-aging periods
| Characteristics | 14 d | 28 d | 35 d | 42 d | 49 d | 56 d | 63 d | 70 d | SEM1 | P Value |
|---|---|---|---|---|---|---|---|---|---|---|
| BF2 | ||||||||||
| L* | 44.57 | 43.43 | 44.45 | 43.70 | 43.44 | 45.03 | 43.81 | 43.65 | 0.65 | .50 |
| a* | 28.85a | 27.88ab | 27.36b | 27.78b | 28.23ab | 28.12ab | 28.44ab | 28.15ab | 0.32 | .05 |
| b* | 20.49 | 19.63 | 19.32 | 19.70 | 20.19 | 20.33 | 20.27 | 20.15 | 0.36 | .25 |
| Hue | 0.62 | 0.61 | 0.61 | 0.62 | 0.62 | 0.63 | 0.62 | 0.62 | 0.00 | .52 |
| Chroma | 35.39 | 34.10 | 33.50 | 34.06 | 34.71 | 34.70 | 34.93 | 34.62 | 0.46 | .11 |
| GM3 | ||||||||||
| L* | 47.95 | 47.33 | 48.04 | 46.31 | 46.65 | 48.51 | 47.39 | 47.07 | 1.03 | .70 |
| a* | 31.36a | 29.24b | 29.89ab | 29.85ab | 29.5b | 29.58ab | 29.58ab | 29.36b | 0.46 | .01 |
| b* | 23.54a | 21.39b | 22.04ab | 21.78ab | 21.52ab | 21.79ab | 21.76ab | 21.46b | 0.53 | .03 |
| Hue | 0.64 | 0.63 | 0.63 | 0.63 | 0.63 | 0.63 | 0.63 | 0.63 | 0.01 | .48 |
| Chroma | 39.21a | 36.23b | 37.14ab | 36.96ab | 36.52b | 36.74ab | 36.73ab | 36.37b | 0.67 | .01 |
| SM4 | ||||||||||
| L* | 48.37a | 46.28ab | 45.23ab | 45.58ab | 45.08ab | 48.25ab | 46.41ab | 44.1b | 1.00 | .01 |
| a* | 30.63a | 29.05ab | 28.7b | 28.79b | 29.77ab | 29.61ab | 29.78ab | 28.67b | 0.38 | <.01 |
| b* | 23.11a | 21.32ab | 20.81b | 21.19b | 21.84ab | 22.11ab | 21.87ab | 20.78b | 0.43 | <.01 |
| Hue | 0.65 | 0.63 | 0.63 | 0.63 | 0.63 | 0.64 | 0.63 | 0.63 | 0.01 | .09 |
| Chroma | 38.37a | 36.03b | 35.46b | 35.75b | 36.92ab | 36.96ab | 36.95ab | 35.42b | 0.55 | <.01 |
Abbreviations: BF, Biceps femoris; GM, Gluteus medius; IMPS, Institutional Meat Purchase Specifications; NAMP, North American Meat Processors Association; SEM, standard error of the means; SM, Semimembranosus.
Largest SEM of the least-squares means, using Kenward-Rogers degrees of freedom proximation.
Top sirloin butt subprimal (IMPS 184, NAMP 2014).
Top sirloin butt subprimal (IMPS 184, NAMP 2014).
Inside round subprimal (IMPS 168, NAMP 2014).
Least-squares means in the same row without a common superscript differ (P < .05).
Biceps femoris
The a* values were impacted by aging duration (P = .05). More specifically, a* values were the lowest after a 35-d aging duration, especially compared to the greatest value at a 14-d aging duration (P < .05), indicating decreased redness with extended-aging durations. Although McKenna et al. (2005) focused on retail color stability, classifying the BF as a color labile muscle, the current study observed a decrease in redness with increased aging, suggesting related declines. Conversely, L*, b*, hue, and chroma values were not affected by aging duration. Additionally, Figure 5 shows the variation in composite instrumental color over 8 aging durations, suggesting a minor instrumental change in overall color differences throughout aging durations that are not easily perceived visually.
Visual1 color values, throughout 8 wet-aging durations, for 3 beef muscles: Biceps femoris, Gluteus medius, and Semimembranosus. 1Inital L*, a* and b* values were converted to RGB for visualization. Abbreviations: BF, Biceps femoris; GM, Gluteus medius; RGB, red-green-blue; SM, Semimembranosus.
Gluteus medius
The GM elicited differences across aging periods for both a* (P = .01) and b* (P = .03) values. Specifically, the GM exhibited decreased a* values at 28-, 49-, and 70-d aging durations in relation to a 14-d aging duration (P < .05), thus indicating redness decreased as aging duration increased. The decrease in redness with longer aging durations observed in the present study aligns with McKenna et al. (2005), who reported that the GM exhibits moderate initial redness and moderate color stability during retail display, indicating this muscle is prone to color deterioration under oxidative conditions. Although muscles in the present study were not subjected to simulated retail display, the observed decline in redness with extended aging suggests that similar oxidative mechanisms influencing color stability may be occurring during prolonged vacuum aging. Likewise, among b* values, 28- and 70-d aging durations exhibited the lowest values compared to a 14-d aging duration (P < .05), indicating that as aging duration increased, yellowness decreased. However, no significant differences in b* values were observed between 28, 49, and 70 d, suggesting that the decline in yellowness plateaued after 28 d of aging. Consistent with the present study findings, King et al. (2011) reports that extended postmortem aging of the Longissimus lumborum muscle resulted in decreased redness, with decreasing values as aging duration increases. Although, King et al. (2011) focused on the loin, the reduction in initial redness observed in the present study indicates that a similar aging effect occurs in the GM. Additionally, chroma values were impacted by aging duration (P = .01), where 28-, 49-, and 70-d aging durations exhibited the lowest chroma values in relation to a 14-d aging duration (P < .05). This reduction in chroma was largely driven by early decreases in b* values, as no differences in b* were observed between 28 and 70 d of aging, indicating that yellowness stabilized after 28 d. L* values were not impacted by aging duration (P = .70). Additionally, Figure 5 shows the minimal variation in composite instrumental color, over 8 aging durations, suggesting minimal or subtle perceptible visual differences between all aging durations.
Semimembranosus
In L* instrumental color evaluation of the SM, values show a general reduction with aging (P = .01). The L* values were greatest at 14 d, especially when compared to 70-d aging duration (P < .05), indicating a decrease in overall lightness as aging duration increased. Similarly, a* values for the SM were impacted by aging duration (P < .01), where 35- and 70-d aging durations exhibited decreased redness compared to a 14-d aging duration (P < .05). Furthermore, b* values were impacted by aging duration (P < .01), as shown by decreased b* values, at 35-, 42-, and 70-d aging durations when considered alongside a 14-d aging duration (P < .05), indicating a decrease in objective yellowness as aging duration increased. The magnitude of change in b* values with aging was relatively small, and no differences were observed from 28 to 70 d, indicating that extended aging had minimal impact on yellowness beyond 28 d. Additionally, chroma values were impacted by aging duration (P < .01), as indicated by decreased values at 28-, 35-, 42-, and 70-d aging durations when evaluated against a 14-d aging duration (P < .05), showing that samples had decreased objective color intensities as aging durations increased. Hue values did not exhibit differences with extended-aging durations (P = .09). Although McKenna et al. (2005) assessed color stability during retail display, they classified the SM as a moderate color stability muscle. This classification, while focused on display conditions, supports the idea that the SM exhibits intermediate color stability, which may be related to the moderate changes in color observed during the present study. Additionally, Figure 5 shows the variation in composite instrumental color over 8 aging durations, suggesting a minor variation in overall color differences throughout all aging durations.
Conclusion
The present data demonstrate that extended wet aging alters the flavor profile of beef BF, GM, and SM muscles. Across all 3 muscles, off-flavor presence generally increased as aging duration increased. Conversely, positive flavor notes such as beef-flavor identity decreased with increased aging duration. However, extended aging was not shown to be detrimental to consumer liking. Instrumental color evaluation revealed minor changes across all muscles, with general decreases in redness as aging duration increased. From a practical standpoint, these findings suggest that wet aging should be managed differently depending on the muscle. Extended aging may provide greater benefit for improving tenderness and consumer acceptability in the SM, whereas prolonged aging in the BF and GM may contribute to increased off-flavor development without clear consumer benefit. These findings provide guidance for muscle-specific aging strategies to better balance tenderness, flavor, and overall product quality across the beef supply chain.
Conflict of Interest
The authors declare no conflicts of interest.
Acknowledgments
Research coordinated by the National Cattlemen’s Beef Association, a contractor to the Beef Checkoff.
Author Contribution
Amelia J. Main: investigation, data curation, formal analysis, visualization, and writing—original draft; Lauren M. Frink: investigation, formal analysis, data curation, visualization, and writing; M. Sebastian Hernandez: investigation, formal analysis, data curation, visualization, and writing—original draft; Travis G. O’Quinn: conceptualization, methodology, supervision, project administration, and writing—review and editing; Jerrad F. Legako: conceptualization, methodology, supervision, project administration, and writing—review and editing; Rhonda K. Miller: conceptualization, methodology, resources, and writing—review and editing; Mahesh N. Nair: conceptualization, methodology, resources, and writing—review and editing; Christopher R. Kerth: conceptualization, methodology, resources, project administration, and writing—review and editing; Jessica M. Landcaster: conceptualization, methodology, resources, and writing—review and editing; and Dale R. Woerner: conceptualization, funding acquisition, methodology, supervision, and writing—review and editing.
Literature Cited
AMSA. 2016. Research guidelines for cookery, sensory evaluation, and instrumental tenderness measurements of meat. 2nd ed. American Meat Science Association, Champaign, IL.
Adhikari, K., E. Chambers, R. Miller, L. Vázquez-Araújo, N. Bhumiratana, and C. Philip. 2011. Development of a lexicon for beef flavor in intact muscle. J. Sens. Stud. 26:413–420. doi: https://doi.org/10.1111/j.1745-459X.2011.00356.x.
Anderson, M. J., S. M. Lonergan, C. A. Fedler, K. J. Prusa, J. M. Binning, and E. Huff-Lonergan. 2012. Profile of biochemical traits influencing tenderness of muscles from the beef round. Meat Sci. 91:247–254. doi: https://doi.org/10.1016/j.meatsci.2012.01.022.
Barker, S. N., J. C. Brooks, J. T. Bachler, D. R. Woerner, and J. F. Legako. 2023. Flavor development of individually vacuum-packaged beef steaks during extended wet aging. Meat and Muscle Biology. 7:16192. doi: https://doi.org/10.22175/mmb.16192.
Bates, D., M. Mächler, B. M. Bolker, and S. Walker. 2015. Fitting linear mixed-effects models using lme4. J. Stat. Softw. 67:1–48. doi: https://doi.org/10.18637/jss.v067.i01.
Bekhit, A. E.-D. A., D. L. Hopkins, F. T. Fahri, and E. N. Ponnampalam. 2013. Oxidative processes in muscle systems and fresh meat: sources, markers, and remedies. Compr. Rev. Food Sci. F. 12:565–597. doi: https://doi.org/10.1111/1541-4337.12027.
Bratcher, C. L., D. D. Johnson, R. C. Littell, and B. L. Gwartney. 2005. The effects of quality grade, aging, and location within muscle on Warner-Bratzler shear force in beef muscles of locomotion. Meat Sci. 70:279–284. doi: https://doi.org/10.1016/j.meatsci.2005.01.013.
Colle, M. J., R. P. Richard, K. M. Killinger, J. C. Bohlscheid, A. R. Gray, W. I. Loucks, R. N. Day, A. S. Cochran, J. A. Nasados, and M. E. Doumit. 2015. Influence of extended aging on beef quality characteristics and sensory perception of steaks from the gluteus medius and longissimus lumborum. Meat Sci. 110:32–39. doi: https://doi.org/10.1016/j.meatsci.2015.06.013.
Colle, M. J., R. P. Richard, K. M. Killinger, J. C. Bohlscheid, A. R. Gray, W. I. Loucks, R. N. Day, A. S. Cochran, J. A. Nasados, and M. E. Doumit. 2016. Influence of extended aging on beef quality characteristics and sensory perception of steaks from the biceps femoris and semimembranosus. Meat Sci. 119:110–117. doi: https://doi.org/10.1016/j.meatsci.2016.04.028.
Dashdorj, D., T. Amna, and I. Hwang. 2015. Influence of specific taste-active components on meat flavor as affected by intrinsic and extrinsic factors: an overview. Eur. Food Res. Technol. 241:157–171. doi: https://doi.org/10.1007/s00217-015-2449-3.
Dinh, T. T. N., K. V. To, and M. W. Schilling. 2021. Fatty acid composition of meat animals as flavor precursors. Meat and Muscle Biology. 5:34. doi: https://doi.org/10.22175/mmb.12251.
Egan, A. F., D. M. Ferguson, and J. M. Thompson. 2001. Consumer sensory requirements for beef and their implications for the Australian beef industry. Anim. Prod. Sci. 41:855–859. doi: https://doi.org/10.1071/EA00065.
Evers, D. L., A. J. Garmyn, J. F. Legako, D. R. Woerner, and M. F. Miller. 2020. Flavor characterization of grass- and grain-fed Australian beef longissimus lumborum wet-aged 45 to 135 days. Meat and Muscle Biology. 4. doi: https://doi.org/10.22175/mmb.11043.
Foraker, B. A., D. A. Gredell, J. F. Legako, R. D. Stevens, J. D. Tatum, K. E. Belk, and D. R. Woerner. 2020. Flavor, tenderness, and related chemical changes of aged beef strip loins. Meat and Muscle Biology. 4:28. doi: https://doi.org/10.22175/mmb.11115.
Gruber, S. L., J. D. Tatum, J. A. Scanga, P. L. Chapman, G. C. Smith, and K. E. Belk. 2006. Effects of postmortem aging and USDA quality grade on Warner–Bratzler shear force values of seventeen individual beef muscles. J. Anim. Sci. 84:3387–3396. doi: https://doi.org/10.2527/jas.2006-194.
Ha, M., P. McGilchrist, R. Polkinghorne, L. Huynh, J. Galletly, K. Kobayashi, T. Nishimura, S. Bonney, K. R. Kelman, and R. D. Warner. 2019. Effects of different ageing methods on colour, yield, oxidation, and sensory qualities of Australian beef loins consumed in Australia and Japan. Food Res. Int. 125:108528. doi: https://doi.org/10.1016/j.foodres.2019.108528.
Hammond, P. A., C. K. Y. Chun, W. J. Wu, A. A. Welter, T. G. O’Quinn, G. Magnin-Bissel, E. R. Geisbrecht, and M. D. Chao. 2022. Influence of various biochemical tenderness factors on eight bovine muscles. Meat and Muscle Biology. 6:13902. doi: https://doi.org/10.22175/mmb.13902.
Hernandez, M. S., D. R. Woerner, J. C. Brooks, T. L. Wheeler, and J. F. Legako. 2022. Influence of aging temperature and duration on spoilage organism growth, proteolytic activity, and related chemical changes in vacuum-packaged beef longissimus. Meat and Muscle Biology. 6:13724. doi: https://doi.org/10.22175/mmb.13724.
Hernandez, M. S., D. R. Woerner, J. C. Brooks, T. L. Wheeler, and J. F. Legako. 2023. Influence of aging temperature and duration on flavor and tenderness development of vacuum-packaged beef longissimus. Meat and Muscle Biology. 7:15710. doi: https://doi.org/10.22175/mmb.15710.
Huff-Lonergan, E., W. Zhang, and S. M. Lonergan. 2010. Biochemistry of postmortem muscle—lessons on mechanisms of meat tenderization. Meat Sci. 86:184–195. doi: https://doi.org/10.1016/j.meatsci.2010.05.004.
Huffman, K. L., M. F. Miller, L. C. Hoover, C. K. Wu, H. C. Brittin, and C. B. Ramsey. 1996. Effect of beef tenderness on consumer satisfaction with steaks consumed in the home and restaurant. J. Anim. Sci. 74:91–97. doi: https://doi.org/10.2527/1996.74191X.
Kerth, C. R., J. F. Legako, D. R. Woerner, J. C. Brooks, J. M. Lancaster, T. G. O’Quinn, M. Nair, and R. K. Miller. 2024. A current review of U.S. beef flavor I: measuring beef flavor. Meat Sci. 210:109437. doi: https://doi.org/10.1016/j.meatsci.2024.109437.
Killinger, K. M., C. R. Calkins, W. J. Umberger, D. M. Feuz, and K. M. Eskridge. 2004. Consumer sensory acceptance and value for beef steaks of similar tenderness, but differing in marbling level. J. Anim. Sci. 82:3294–3301. doi: https://doi.org/10.2527/2004.82113294X.
King, D. A., S. D. Shackelford, and T. L. Wheeler. 2011. Relative contributions of animal and muscle effects to variation in beef lean color stability. J. Anim. Sci. 89:1434–1451. doi: https://doi.org/10.2527/jas.2010-3595.
King, D. A., M. C. Hunt, S. Barbut, J. R. Claus, D. P. Cornforth, P. Joseph, Y. H. B. Kim, G. Lindahl, R. A. Mancini, M. N. Nair, K. J. Merok, A. Milkowski, A. Mohan, F. Pohlman, R. Ramanathan, C. R. Raines, M. Seyfert, O. Sørheim, S. P. Suman, and M. Weber. 2023. American Meat Science Association guidelines for meat color measurement. Meat and Muscle Biology. 6:12473. doi: https://doi.org/10.22175/mmb.12473.
King, D. A., S. D. Shackelford, R. A. Cushman, and T. L. Wheeler. 2021. Extended aging and marbling class effects on color stability of beef longissimus lumborum, gluteus medius, and biceps femoris steaks. Meat and Muscle Biology. 5:21. doi: https://doi.org/10.22175/mmb.11139.
Koutsidis, G., J. S. Elmore, M. J. Oruna-Concha, M. M. Campo, J. D. Wood, and D. S. Mottram. 2008. Water-soluble precursors of beef flavour. Part II: effect of post-mortem conditioning. Meat Sci. 79:270–277. doi: https://doi.org/10.1016/j.meatsci.2007.09.010.
Kuhn, M. 2008. Building predictive models in R using the caret package. J. Stat. Softw. 28:1–26. doi: https://doi.org/10.18637/jss.v028.i05.
Laster, M. A., R. D. Smith, K. L. Nicholson, J. D. W. Nicholson, R. K. Miller, D. B. Griffin, K. B. Harris, and J. W. Savell. 2008. Dry versus wet aging of beef: retail cutting yields and consumer sensory attribute evaluations of steaks from ribeyes, strip loins, and top sirloins from two quality grade groups. Meat Sci. 80:795–804. doi: https://doi.org/10.1016/j.meatsci.2008.03.024.
Lenth, R. 2022. Emmeans: estimated marginal means. R Foundation for Statistical Computing, Vienna, Austria.
Lepper-Blilie, A. N., E. P. Berg, D. S. Buchanan, and P. T. Berg. 2016. Effects of post-mortem aging time and type of aging on palatability of low marbled beef loins. Meat Sci. 112:63–68. doi: https://doi.org/10.1016/j.meatsci.2015.10.017.
Li, X., J. Babol, W. L. P. Bredie, B. Nielsen, J. Tománková, and K. Lundström. 2014. A comparative study of beef quality after ageing longissimus muscle using a dry ageing bag, traditional dry ageing, or vacuum package ageing. Meat Sci. 97:433–442. doi: https://doi.org/10.1016/j.meatsci.2014.03.014.
Lonergan, S. M., E. Huff-Lonergan, B. R. Wiegand, and L. A. Kriese-Anderson. 2001. Postmortem proteolysis and tenderization of top loin steaks from Brangus cattle. J. Muscle Foods. 12:121–136. doi: https://doi.org/10.1111/j.1745-4573.2001.tb00304.x.
Martinez, H. A., A. N. Arnold, J. C. Brooks, C. C. Carr, K. B. Gehring, D. B. Griffin, D. S. Hale, G. G. Mafi, D. D. Johnson, C. L. Lorenzen, R. J. Maddock, R. K. Miller, D. L. VanOverbeke, B. E. Wasser, and J. W. Savell. 2017. National Beef Tenderness Survey—2015: palatability and shear force assessments of retail and foodservice beef. Meat and Muscle Biology. 1. doi: https://doi.org/10.22175/mmb2017.05.0028.
McKenna, D. R., P. D. Mies, B. E. Baird, K. D. Pfeiffer, J. W. Ellebracht, and J. W. Savell. 2005. Biochemical and physical factors affecting discoloration characteristics of 19 bovine muscles. Meat Sci. 70:665–682. doi: https://doi.org/10.1016/j.meatsci.2005.02.016.
Miller, M. F., K. L. Huffman, S. Y. Gilbert, L. L. Hamman, and C. B. Ramsey. 1995. Retail consumer acceptance of beef tenderized with calcium chloride. J. Anim. Sci. 73:2308–2314. doi: https://doi.org/10.2527/1995.7382308X.
Miller, R. 2020. Drivers of consumer liking for beef, pork, and lamb: a review. Foods. 9:428. doi: https://doi.org/10.3390/foods9040428.
Oksanen, J., G. L. Simpson, F. G. Blanchet, R. Kindt, P. Legendre, P. R. Minchin, R. B. O’Hara, P. Solymos, M. H. H. Stevens, E. Szoecs, H. Wagner, M Barbour, M. Bedward, B. Bolker, D. Borcard, T. Boreman, G. Carvalho, M. Chirico, M. De Caceres, S. Durand, H. B. A. Evangelist, R. FitzJohn, M. Friendly, B. Furneaux, G. Hannigan, M. O. Hill, L. Lahti, C. Martino, D. McGlinn, M.-H. Ouellette, E. R. Cunha, T. Smith, A Stier, C. J. F. Ter Braak, and J. Weedon. 2024. Vegan: community ecology package. R package version 2.6-8.
O’Quinn, T. G., J. F. Legako, D. R. Woerner, C. R. Kerth, M. N. Nair, J. C. Brooks, J. M. Lancaster, and R. K. Miller. 2024. A current review of U.S. beef flavor II: managing beef flavor. Meat Sci. 210:109403. doi: https://doi.org/10.1016/j.meatsci.2023.109403.
O’Quinn, T. G., D. R. Woerner, T. E. Engle, P. L. Chapman, J. F. Legako, J. C. Brooks, K. E. Belk, and J. D. Tatum. 2016. Identifying consumer preferences for specific beef flavor characteristics in relation to cattle production and postmortem processing parameters. Meat Sci. 112:90–102. doi: https://doi.org/10.1016/j.meatsci.2015.11.001.
Paradis, E., and K. Schliep. 2019. ape 5.0: an environment for modern phylogenetics and evolutionary analyses in R. Bioinformatics. 35:526–528. doi: https://doi.org/10.1093/bioinformatics/bty633.
R Core Team. (2022). R: A language and environment for statistical computing (Version 4.2.0). R Foundation for Statistical Computing. https://www.R-project.org/https://www.R-project.org/
Rhee, M. S., T. L. Wheeler, S. D. Shackelford, and M. Koohmaraie. 2004. Variation in palatability and biochemical traits within and among eleven beef muscles. J. Anim. Sci. 82:534–550. doi: https://doi.org/10.2527/2004.822534x.
Schwarz, M. W., W. B. Cowan, and J. C. Beatty. 1987. An experimental comparison of RGB, YIQ, LAB, HSV, and opponent color models. ACM Transactions on Graphics. 6:123–158. doi: https://doi.org/10.1145/31336.31338.
Smith, A. M., K. B. Harris, D. B. Griffin, R. K. Miller, C. R. Kerth, and J. W. Savell. 2014. Retail yields and palatability evaluations of individual muscles from wet-aged and dry-aged beef ribeyes and top sirloin butts that were merchandised innovatively. Meat Sci. 97:21–26. doi: https://doi.org/10.1016/j.meatsci.2013.12.013.
Smith, G. C., G. R. Culp, and Z. L. Carpenter. 1978. Postmortem aging of beef carcasses. J. Food Sci. 43:823–826. doi: https://doi.org/10.1111/j.1365-2621.1978.tb02430.x.
Smith, R. D., K. L. Nicholson, J. D. W. Nicholson, K. B. Harris, R. K. Miller, D. B. Griffin, and J. W. Savell. 2008. Dry versus wet aging of beef: retail cutting yields and consumer palatability evaluations of steaks from US Choice and US Select short loins. Meat Sci. 79:631–639. doi: https://doi.org/10.1016/j.meatsci.2007.10.028.
Théron, L., and M. Estévez. 2022. Recent advances in meat oxidation. In: P. Purslow, editor, New aspects of meat quality: from genes to ethics. 2nd edition. Woodhead Publishing, Cambridge, UK. p. 115–137.
Thompson, J. 2002. Managing meat tenderness. Meat Sci. 62:295–308. doi: https://doi.org/10.1016/S0309-1740(02)00126-2.
Vierck, K. R., J. F. Legako, J. Kim, B. J. Johnson, and J. C. Brooks. 2020. Determination of package and muscle-type influence on proteolysis, beef-flavor-contributing free amino acids, final beef flavor, and tenderness. Meat and Muscle Biology. 4. doi: https://doi.org/10.22175/mmb.10933.