The objective of this study was to evaluate the effects of rosemary/beef flavor enhancement and modified atmosphere packaging (MAP) on retail display color and palatability of beef
Beef palatability and color are the two most important quality characteristics that influence eating experience and purchasing decisions, respectively (
Many approaches, such as lowering muscle pH (
Greater-than-normal pH can influence lactic acid levels, water-holding capacity, and proteolysis. The research determining the palatability of dark-cutting beef is not consistent (
Five USDA Low Choice (normal-pH) and eight dark-cutting beef carcasses (pH > 6.0) were selected, identified, and marked prior to fabrication from Creekstone Farms in Arkansas City, KS, within 72 h of harvest. Care was taken to limit variation between carcasses and have similar marbling. Carcasses were fabricated, and strip loins were collected (
The enhancement solution was prepared by mixing deionized water stored at 2°C with 1.1% rosemary (Herbalox oleoresin rosemary, Kalsec, Kalamazoo, MI), 5% salt, and 5.5% beef flavor (ProBase B3301 Spray-Dried Beef Flavor; Essentia Protein Solutions, Ankeny, IA) using a handheld mixer for 2 min and stored under refrigerated temperature at 2°C for 24 h. Prior to enhancement, the solution was remixed to distribute the ingredients uniformly. Each loin section was individually weighed prior to enhancement to determine the green weight and calculate the percent pump. The average injection level was 10.8%, standard error = 0.6.
After the 14-d aging period, high-pH loin sections were then individually pumped to 110% of green weight with a handheld multi-needle injection system (Leeson motor; Grafton, WI) to achieve 0.1% rosemary, 0.5% salt, and 0.55% beef flavor in the final product. Sections were vacuum tumbled utilizing a Koch LT-15 vacuum tumbler (Koch; UltraSource USA, Kansas City, MO) at 12 psi for 5 min. Plastic tags were used to track the identity of loin sections during tumbling (Laser 3 Meat Fasteners, M63-Y Yellow, Meyers & Sons, Korea). The sections were re-weighed to measure the injection level percentage (10% of green weight). The injection level was calculated as (postenhancement loin section weight ÷ loin section weight prior to enhancement) × 100.
The pH of Choice, nonenhanced dark-cutting, and enhanced dark-cutting strip loin sections were determined by inserting a pH probe at 4 different locations using a Mettler Toledo SevenGo pH meter (Mettler Toledo, Colombus, OH).
Six 2.54-cm-thick steaks were cut from the anterior end of each normal-pH USDA Choice, nonenhanced dark-cutting, and enhanced dark-cutting strip loin sections and were assigned to one of 3 packaging treatments: (1) vacuum packaging (VP), (2) CO-MAP (0.4% CO, 69.6% N, and 30% CO2), and (3) HiOx-MAP (80% O2 and 20% CO2). For USDA Choice sections, 5 loins × 6 steaks = 30 ÷ 3 = 10 steaks per packaging treatment, and for dark-cutting sections, 8 loins × 6 steaks = 48 ÷ 3 = 18 steaks per packaging treatment. Steaks assigned to CO-MAP and HiOx-MAP packaging were placed in Rock-Tenn DuraFresh rigid trays (22.2 cm × 17.1 cm × 4.5 cm; RockTenn Company, Norcross, GA) and sealed with clear, multilayer barrier film (1 mil, < 20 cm3 O2/m2/24 h, at 4.4°C, LID 1050 film; Cryovac Sealed Air, Duncan, SC). The CO- and HiOx-MAP packaging was accomplished utilizing a Mondini semiautomatic tray-sealing machine (Model: CV/VG-5, G.; Mondini, Cologne, Italy) and certified gas blends (Stillwater Steel, Stillwater, OK). Gas compositions within the packages (O2, CO, and CO2) were measured utilizing a headspace analyzer (Bridge 900131 O2/CO2/CO; Illinois Instruments, Ingleside, IL) 5 h after packaging. The headspace analysis indicated that the average gas compositions were 0.34% and 76% carbon monoxide and oxygen, respectively.
Packages were randomly placed in a coffin-style retail display case under continuous fluorescent lighting (Philips Fluorescent lamps; 12 Watts, 48 inches; Philips, China; color temperature = 3,500 K) and maintained at 2°C ± 1°C for 5 d. The light intensity within the display case ranged from 714 to 1,150 lx (Extech Instruments Corporation, Waltham, MA). To limit the impact of location within the display case, the packages were rotated daily and remained in the retail case for 3 d. Following 3-d retail display, the instrumental color was measured using a HunterLab MiniScan XE Plus spectrophotometer (2.5-cm aperture, Illuminant A, and 10° standard observed angle; HunterLab Associates, Reston, VA) to measure surface color at 2 locations on each steak. Objective measures of
Proximate compositions of each normal-pH and nonenhanced dark-cutting steaks were determined on 14-d-aged samples (
Trained sensory panel methods were approved by the Institutional Review Board (Protocol Number: AG1528) of Oklahoma State University. The panelists were trained to become familiar with the Beef Flavor Lexicon (
Following color measurements, steaks in MAP were repackaged in vacuum and frozen at −20°C until use. For sensory evaluation, steaks were thawed under refrigerated conditions at 4°C for 24 h. Steaks were cooked on an XLT Impingement Oven (model 3240-TS, BOFI Inc., Wichita, KS) set at 200°C to an internal temperature of 68°C. Steak internal temperature was monitored using a handheld probe thermometer (AccuTuff 340, Atkins, Gainesville, FL) inserted into the geometric center. Cooked steaks were cut into 1-cm3 cubes; 2 cubes were then placed in a sample cup, assigned a random number, and placed in warmers with hot packs to maintain temperature through sensory evaluation. Sensory panelists characterized samples under red lighting and were given deionized water and unsalted saltine crackers to use as palate cleansers between samples. Panelists assigned steak attributes for each sample utilizing a 3-point scale for beef flavor, sour flavor, metallic flavor, and off-flavor (1 = not detectable, 2 = slightly, 3 = strong) and utilizing an 8-point scale for overall juiciness and overall tenderness (1 = extremely dry/tough, 8 = extremely juicy/tender).
Following day 3 color measurements, the steaks were frozen at −20°C until use. For Warner-Bratzler shear force evaluation, steaks were thawed under refrigerated conditions at 4°C for 24 h. Steaks were cooked on an XLT Impingement Oven (model 3240-TS, BOFI Inc., Wichita, KS) set at 200°C to an internal temperature of 68°C. Cooked steaks were placed in a tray, covered with aluminum foil, and placed in refrigerated conditions (4°C) for 18 h prior to Warner-Bratzler shear force evaluation. Chilled steaks equilibrated to room temperature (approximately 30 min) before being trimmed of visible fat and heavy connective tissue to expose muscle fiber orientation. From each steak, six 1.27-cm cores were removed parallel to the muscle fibers using a handheld coring device. A Warner-Bratzler Meat Shear attachment for an Instron Universal Testing Machine (Model 5943, Intron Corporation, Norwood, MA) was used to determine maximum shear force value. The crosshead speed was 200 mm/min, and the software utilized was Bluehill 3 (Instron Corporation, Norwood, MA). A maximum load (Newton) was recorded for each core. The mean maximum shear force values were used for statistical analysis.
A completely randomized block design was utilized to determine the effects of improved color on palatability (
Proximate analysis of dark-cutting and normal-pH steak sections showed no differences in protein and fat percentages (
Proximate compositions and pH of USDA Choice and dark-cutting steaks
Muscle Treatment | Moisture, % | Fat, % | Protein, % |
---|---|---|---|
Normal-pH USDA Choice | 66.43 | 7.78 | 22.86 |
Nonenhanced Dark-Cutter | 70.02 | 7.31 | 21.48 |
Standard Error | 0.43 | 0.84 | 0.58 |
< 0.0001 | 0.45 | 0.14 | |
Normal-pH USDA Choice | 5.6 | 5.5–5.6 | |
Nonenhanced Dark-Cutter | 6.4 | 6.2–6.4 | |
Enhanced Dark-Cutter | 6.3 | 6.1–6.3 | |
Standard Error | 0.04 | ||
< 0.001 |
Least-squares means within a parameter lacking a common letter differ (
There was a significant packaging × muscle treatment interaction resulted for
Least-squares means of packaging
Packaging Type | VP | CO-MAP | HiOx-MAP | SEM | VP | CO-MAP | HiOx-MAP | SEM |
---|---|---|---|---|---|---|---|---|
USDA Choice | 38.20 | 41.88 | 44.87 | 0.93 | 16.23 | 25.25 | 30.47 | 0.61 |
Nonenhanced dark-cutter | 31.92 | 36.39 | 35.75 | 0.79 | 17.86 | 22.37 | 25.02 | 0.4 |
Enhanced dark-cutter | 35.57 | 36.58 | 37.68 | 0.79 | 19.62 | 27.15 | 27.59 | 0.4 |
< 0.0001 |
Steaks from each treatment were packaged in one of 3 packaging types: vacuum packaging (VP), carbon monoxide modified atmosphere packaging (CO-MAP; 0.4% carbon monoxide), and high-oxygen modified atmosphere packaging (HiOx-MAP; 80% oxygen).
Least-squares means within a color measurement lacking a common letter differ (
CIE, Commission Internationale de l’Éclairage (International Commission on Illumination); SEM, standard error of the mean.
Enhanced dark-cutting steaks had greater (
Enhancement main effects of trained panelists’ scores
Main Effects | Beef Flavor | SEM | Metallic Flavor | SEM | Sour Flavor | SEM | Off-Flavor | SEM | Overall Juiciness | SEM | Overall Tenderness | SEM |
---|---|---|---|---|---|---|---|---|---|---|---|---|
USDA Choice | 2.09 | 0.07 | 1.29 | 0.03 | 1.08 | 0.05 | 1.38 | 0.07 | 6.55 | 0.09 | 6.50 | 0.11 |
Nonenhanced dark-cutter | 2.06 | 0.06 | 1.33 | 0.04 | 1.37 | 0.06 | 1.47 | 0.06 | 6.48 | 0.08 | 6.87 | 0.09 |
Enhanced dark-cutter | 1.88 | 0.06 | 1.22 | 0.03 | 1.44 | 0.05 | 1.90 | 0.06 | 6.76 | 0.08 | 7.03 | 0.09 |
0.05 | 0.12 | < 0.0001 | < 0.001 | 0.04 | 0.001 | |||||||
HiOx-MAP | 2.00 | 0.06 | 1.25 | 0.04 | 1.33 | 0.05 | 1.66 | 0.07 | 6.48 | 0.08 | 6.86 | 0.10 |
CO-MAP | 1.99 | 0.06 | 1.33 | 0.04 | 1.17 | 0.05 | 1.48 | 0.07 | 6.73 | 0.08 | 6.70 | 0.10 |
VP | 1.99 | 0.06 | 1.25 | 0.04 | 1.39 | 0.05 | 1.60 | 0.07 | 6.57 | 0.08 | 6.85 | 0.10 |
0.98 | 0.26 | 0.01 | 0.15 | 0.11 | 0.40 |
Trained panelists used the following scales: beef flavor, sour flavor, metallic flavor, and off-flavor were determined using a 3-point scale (1 = not detectable, 2= slight, 3 = strong); overall juiciness and overall tenderness were evaluated utilizing an 8-point scale (1 = extremely dry, 8 = extremely juicy; 1 = extremely tough, 8 = extremely tender).
Steaks from each treatment were packaged in one of 3 packaging types: vacuum packaging (VP), carbon monoxide modified atmosphere packaging (CO-MAP; 0.4% carbon monoxide), and high-oxygen modified atmosphere packaging (HiOx-MAP; 80% oxygen).
Means within a trained panel attribute lacking a common letter differ (
SEM, standard error of the mean.
There was a packaging × muscle treatment interaction (
Least-squares means of packaging
Packaging | ||||
---|---|---|---|---|
Muscle Treatment | VP | CO-MAP | HiOx-MAP | SEM |
USDA Choice | 1.40 | 1.20 | 1.50 | 0.09 |
Nonenhanced Dark-Cutter | 1.02 | 1.10 | 1.12 | 0.08 |
Enhanced Dark-Cutter | 1.74 | 1.22 | 1.36 | 0.08 |
0.006 |
Steaks from each treatment were packaged in one of 3 packaging types: vacuum packaging (VP), carbon monoxide modified atmosphere packaging (CO-MAP; 0.4% carbon monoxide), and high-oxygen modified atmosphere packaging (HiOx-MAP; 80% oxygen). Trained panelist determined sour flavor using a 3-point scale (1 = not detectable, 3 = strong).
Least-squares means within a color measurement lacking a common letter differ (
SEM, standard error of the mean.
There were no muscle treatment or packaging differences (
Least-squares means for Warner-Bratzler shear values
Main Effects | WBS (N) | SEM |
---|---|---|
USDA Choice | 18.14 | 1.27 |
Nonenhanced dark-cutter | 22.06 | 1.08 |
Enhanced dark-cutter | 18.93 | 1.08 |
0.07 | ||
HiOx-MAP | 20.10 | 1.27 |
CO-MAP | 20.20 | 1.27 |
VP | 18.63 | 1.27 |
0.70 |
CO-MAP, carbon monoxide modified atmosphere packaging; HiOx-MAP, high-oxygen modified atmosphere packaging; SEM, standard error of the mean; VP, vacuum packaging; WBS, Warner-Bratzler shear.
Dark-cutting beef results from antemortem stress, decreasing the glycogen content in the muscle (
Previous research determined the effects of packaging on the color characteristics of dark-cutting beef. In aerobic conditions, normal-pH steaks have greater
In the current research, salt and beef flavor were added to offset any flavor issues in dark-cutting steaks. The addition of salt could have had effects on the color of the enhanced dark-cutting steaks. Research has shown that salt enhancement decreases the
Research has shown that more “off-flavors” in dark-cutting steaks compared with normal-pH steaks (
The pH of meat has been shown to have a curvilinear relationship with tenderness (
In enhanced dark-cutting steaks, the enhancement did not have a significant impact on the tenderness of the dark-cutting steaks. Previous research has noted that salt increases the tenderness of normal-pH meat (
When evaluating juiciness, dark-cutting steaks have similar moisture release and juiciness compared to normal-pH steaks at a high pH (6.7–6.8) (
Developing postharvest processes to improve color and palatability is important to maximize the value and marketability of dark-cutting beef. In the current research, a combination of rosemary/beef flavor enhancement and MAP improved the redness of dark-cutting steaks. The inclusion of beef flavor with salt did not improve the lightness of dark-cutting steaks in HiOx-MAP and CO-MAP. The trained panelists did not observe differences in metallic flavor between Choice and enhanced dark-cutting steaks. However, the overall tenderness of enhanced dark-cutting steaks was greater than Choice steaks. The results indicate that adopting postharvest processing such as packaging or injection enhancement technology can improve color without adversely affecting palatability traits.