Effects of vitamin E on color stability and palatability of strip loin · PDF file · 2017-06-18the products in a display case begin to discolor, ... Pfizer Animal Health, Stillwater,

Effects of vitamin E on color stability and palatability of strip loin steaks from cattle fed distillers grains

B. D. Bloomberg, G. G. Hilton, K. G. Hanger,1 C. J. Richards, J. B. Morgan,2 and D. L. VanOverbeke3

Department of Animal Science, Oklahoma State University, Stillwater 74078

ABSTRACT: The objective of this study was to de-termine the effect of preslaughter antioxidant supple-mentation to cattle fed wet distillers grains on carcass yield and quality grade, and on the color stability and consumer acceptability of steaks. Two hundred five crossbred steers were fed 35% wet distillers grains with the supplementation of 4 different levels of α-tocopheryl acetate: 0, 125, 250, and 500 IU∙animal−1∙d−1 for 97 d. Chuck rolls (n = 69) and strip loins (n = 185) were collected and processed at 4 and 7 d postslaughter, respectively. Chucks were ground and separated into 0.23-kg samples. Strip loins were faced and cut into 2.54-cm steaks and packaged in a polyvinyl chloride overwrapped (PVC) package, a vacuum package, or modified atmosphere packages (MAP) for further col-or, α-tocopherol, objective tenderness, palatability, and proximate analysis. Color was measured objectively using a HunterLab Miniscan XE spectrophotometer (HunterLab Associates Inc., Reston, VA) and subjec-tively by a trained color panel, and a consumer panel was used to indicate which treatments affected retail acceptability and purchase decisions. Warner-Bratzler shear force measurements were used for objective ten-derness, and a trained panel assessed subjective pal-

atability characteristics. Instrumental color measure-ments revealed little difference for ground beef in both PVC and MAP packages, but diets with 500 and 250 IU∙animal−1∙d−1 of vitamin E had a longer (P < 0.05) retention of redness and yellowness in steaks as com-pared with steaks from animals receiving less vitamin E. Subjective color evaluation for strip steaks indicated that greater vitamin E was more likely (P < 0.05) to maintain color stability, overall acceptability, and con-sumer purchase preference while decreasing percentage of discoloration. No significant differences (P > 0.10) were observed for objective tenderness and sensory at-tributes of strip steaks, and no differences (P > 0.10) were observed in protein, fat, and moisture percentages of ground beef. Lipid oxidation analysis indicated that steaks packaged in PVC for 7 d and MAP for 1, 3, and 7 d, and ground beef packaged in MAP and PVC for 0 and 7 d of retail display required greater inclusion of vitamin E (500 and 250 IU∙animal−1∙d−1) to remain below the 2.28 mg of malonaldehyde/kg threshold. Ul-timately, 500 IU∙animal−1∙d−1 of vitamin E should be supplemented to cattle fed wet distillers grain-based diets when products are packaged in MAP to maximize retail shelf life.

Key words: beef, color stability, palatability, vitamin E, wet distillers grain

©2011 American Society of Animal Science. All rights reserved. J. Anim. Sci. 2011. 89:3769–3782 doi:10.2527/jas.2011-3843

INTRODUCTION

One of the greatest factors affecting beef retail mar-kets is the loss of profit caused by meat discoloration. At the point at which beef products begin to darken, a retailer is forced to do 1 of 3 things: 1) discount or mark down the price of the product, 2) convert the product

to a new product of lesser value (e.g., grinding to ham-burger), or 3) discard the product at a 100% loss. Thus, retailers may be more interested in how many hours of acceptable retail display they can gain before 10% of the products in a display case begin to discolor, rather than when the average number of all the cuts in the display case is unacceptable (Zerby et al., 1999).

Studies have been conducted to increase color sta-bility in lean. Arnold et al. (1992) determined that α-tocopherol (vitamin E) is effective in extending the color stability of displayed beef, and Faustman et al. (1998) confirmed that vitamin E supplementation of beef cattle diets is an effective procedure for enhancing the lipid and color stability of meat products subse-quently obtained from animals.

1 Current address: National Beef Packing Company, Kansas City, MO 64195.

2 Current address: Pfizer Animal Health, Stillwater, OK 74074.3 Corresponding author: [email protected] January 4, 2011.Accepted June 13, 2011.

3769

Published December 4, 2014

As important as color stability is to retailers, raising cattle economically is of equal importance to produc-ers. It is estimated that in the future, 23% of the corn produced will go to the production of ethanol (Baker and Zahniser, 2006), and with this comes a coproduct, distillers grains, a feedstuff available to producers at a more economical price than corn. Research on the inclusion of distillers grains in finishing diets indicates increases in final BW and ADG and a heavier carcass weight (Koger et al., 2004). However, inclusion of dis-tillers grains can increase the amount of PUFA, result-ing in greater lipid oxidation, the chemical change that causes the brown color in beef (Gill et al., 2008).

The objectives of this study were to determine the effects of preslaughter vitamin E supplementation on carcass yield and quality grade factors, palatability, col-or stability, and consumer acceptability of steaks and ground beef from cattle fed wet distillers grains.

MATERIALS AND METHODS

The Oklahoma State University Institutional Review Board and Institutional Animal Care and Use Com-mittee approved the experimental protocol used in the present study.

Dietary Treatments

Crossbred steers (n = 199) were fed at a commercial feedlot facility to evaluate animal performance in re-sponse to feeding a basal diet of dry-rolled corn (55% on a DM basis) and wet distillers grains (35% on a DM basis), with the supplementation of α-tocopheryl acetate. The steers were allotted to 1 of 4 vitamin E supplementation treatment groups (6 pens per treat-ment): 0 IU∙animal−1∙d−1 (the control group; CON) or 125, 250, or 500 IU∙animal−1∙d−1 for 97 d. Perfor-mance and feedlot data are reported by D. B. Burken (University of Nebraska), K. G. Hanger, R. B. Hicks (Oklahoma State University Panhandle Research and Extension Center, Goodwell), D. L. VanOverbeke, J. L. Wahrumnd (Oklahoma State University), B. P. Hol-land (South Dakota State University), C. R. Krehbiel (Oklahoma State University), P. K. Camfield (Okla-homa Panhandle State University, Goodwell), and C. J. Richards (unpublished data).

Slaughter and Data Collection

The steers were shipped to a commercial process-ing facility in Dodge City, KS, on 2 different slaughter dates (slaughter group 1 processed on July 27, 2009, n = 80; slaughter group 2 processed on August 17, 2009, n = 119), resulting from the difference in final BW over the 6 different BW blocks. On the day of slaughter, trained Oklahoma State University personnel complet-ed tag transfer and collected HCW. After a 36-h chill

and a bloom time of approximately 15 min, the same personnel collected all carcass data on the grade chain, including marbling score and LM at the 12th- and 13-rib interface, KPH percentage, fat thickness, and lean and skeletal maturity. All USDA Quality and Yield Grades were calculated according to the data collected.

Strip Loin and Chuck Collection

Immediately after data collection, carcasses were railed into the sales cooler onto 1 of 2 grade rails (Choice or Select) to allow for tagging of strip loins and chucks. Approximately 60% of the carcasses were grad-ed USDA Choice by a USDA grader, and the other 40% were graded USDA Select. Chuck rolls were collected only from carcasses in the initial slaughter group. A total of 69 chuck rolls were collected from the right side of each carcass (17, CON; 16, 125 IU∙animal−1∙d−1; 19, 250 IU∙animal−1∙d−1; 17, 500 IU∙animal−1∙d−1). All strip loins from the right side of each carcass were tagged over both slaughter dates, and a total of 185 loins were collected (53, CON; 45, 125 IU∙animal−1∙d−1, 46, 250 IU∙animal−1∙d−1; 41, 500 IU∙animal−1∙d−1). The 14 car-casses that graded Prime or No Roll were not used during strip loin and chuck roll collection. All prod-ucts were fabricated according to Institutional Meat Purchase Specifications (IMPS; USDA, 1996), where chucks were fabricated according to the guidelines for IMPS #116A and strip loins were fabricated accord-ing to IMPS #180 with a purchaser-specified option of 2.5 × 0 cm, and were vacuum packaged at the plant. Once the product was vacuum packaged, it was then immediately shipped to Food and Agricultural Prod-ucts Center at Oklahoma State University for further processing.

Chuck Roll Preparation

Chuck rolls (n = 69) were aged 4 d postmortem at 2°C, removed from the vacuum package, and ground. Five 0.23-kg samples of finely ground product were collected and separated into different packages. One sample was placed in a Styrofoam tray with a soaker pad and overwrapped with a polyvinyl chloride (PVC) film for retail display, 1 sample was placed in a vacuum package and frozen immediately for thiobarbituric acid reactive substances (TBARS) testing and placed in a freezer at −20°C, and 1 sample was placed in a Whirl-Pak bag (Ft. Atkinson, WI) for protein, fat, and mois-ture analysis and was also frozen at −20°C. The final 2 samples were placed in plastic trays with a soaker pad and sealed in a high-oxygen modified atmosphere pack-age (MAP; approximately 75% O2 and 25% CO2). The MAP packages were placed in dark storage at 2°C for 7 d before retail display, whereas the PVC packages were immediately objectively color scored with a HunterLab Miniscan XE spectrophotometer (HunterLab Associ-ates Inc., Reston, VA) and placed under retail lighting.

3770 Bloomberg et al.

Strip Loin Preparation

After aging for 7 d postmortem at 2°C, strip loins (n = 185) were removed from their vacuum packages. Strip loins were then faced on the anterior end and six 2.54-cm steaks were cut. The face steak was vacuum packaged and immediately frozen at −20°C for further analysis of α-tocopherol concentrations. The samples were placed in plastic trays with a soaker pad and sealed in a high-oxygen MAP package (approximately 75% O2 and 25% CO2). The first steak was divided in halves horizontally, allowing for one-half the steak to be vacuum packaged and frozen at −20°C for predisplay TBARS testing and the other one-half to be placed in a white MAP package and placed under retail display at 14 d postmortem for TBARS testing after 72 h in display. The second steak was placed in a Styrofoam package with a white soaker pad and overwrapped with PVC film. This steak was then objectively color scored using a HunterLab Miniscan XE spectrophotometer (HunterLab Associates Inc.) and immediately placed under retail lighting. The third steak was selected for Warner-Bratzler shear force (WBSF) analysis, placed in a white MAP package, and aged in dark storage at 2°C for an additional 7 d before being placed un-der retail lighting for 72 h. After this period, steaks were vacuum packaged and frozen at −20°C. The fi-nal 3 steaks were placed in white MAP packages and designated to 1 of 3 display periods: MAP 1-d retail display, MAP 3-d retail display, or MAP 7-d retail dis-play. All MAP packages were placed in dark storage at 2°C for an additional 7 d postmortem to simulate commercial transportation. All MAP 1-d packages were immediately removed from dark storage, placed in a vacuum package, and frozen at −20°C for later TBARS analysis. The MAP 3-d packages were kept under retail lighting for 72 h before being vacuum packaged and frozen at −20°C for sensory analysis. The final MAP 7-d package was held under retail lighting for subjective color scoring for 156 h before being vacuum packaged and frozen at −20°C for final TBARS analysis.

Simulated Retail Display

Products designated for retail display were placed in a room designed to simulate retail conditions. The room contained multiple shelving units from which 121.9-cm Phillips Deluxe Warm White fluorescent lights (Phil-lips Lighting Co., Salina, KS) were hung, exposing the surface of the meat to continuous light at 807 to 1,614 lx for the entire period of retail display. The room was maintained at a temperature of 4 ± 1°C.

Objective Color Evaluation

The objective color of each steak was measured with a HunterLab Miniscan XE spectrophotometer equipped with a 6-mm aperture, Illuminant D65 (HunterLab As-sociates Inc.) to determine color coordinate values for

L* (brightness: 0 = black, and 100 = white), a* (red-ness/greenness: positive values = red, and negative values = green), and b* (yellowness/blueness: positive values = yellow, and negative values = blue) in ac-cordance with the procedures of the CIE (1976). Each time color was measured, 3 readings were taken from different places on the surface exposed to continuous light to obtain average L*, a*, and b* values. Objec-tive color measurements for PVC-packaged steaks were taken at 12, 60, 108, and 156 h, and PVC-packaged ground beef measurements were taken at 72 and 156 h. For objective measurement of MAP-packaged products, the steak packages were removed at 12, 72, and 156 h, and ground beef packages were removed at 156 h for evaluation.

Subjective Color Measurement

A 6-member panel of trained Oklahoma State Uni-versity personnel was selected to subjectively color score all products for a 7-d period at 12-h intervals. All panelists were required to obtain a passing score using Munsell color tiles and the Munsell Color Scoring Sys-tem (Gretamacbeth, New Windsor, NY) before serv-ing on the panel (American Meat Science Association, 1991). Each panelist evaluated both the ground beef and strip steaks for muscle color, percentage of surface discoloration (percentage of metmyoglobin), and overall acceptability. Muscle color was evaluated on an 8-point scale, where one-half-point increments were accepted (1 = very bright red or pinkish red, and 8 = tan to brown); discoloration was scored using a 7-point scale (1 = no discoloration or 0%, and 7 = total discoloration or 100%); and overall acceptability was depicted using an 8-point scale (8 = extremely desirable or acceptable, and 1 = extremely undesirable or unacceptable).

Consumer Color Measurement

Four groups of both male and female consumer pan-elists, whose educational background spanned from high school graduate to advanced college degrees, with an annual household income level from $10,000 to more than $100,000, and who purchased beef an average of once a week to once a year, participated on color evalu-ation panels for both PVC-packaged steaks (15 panel-ists for slaughter group 1, and 16 panelists for slaughter group 2) and MAP-packaged steaks (13 panelists for slaughter group 1, and 18 for slaughter group 2). Steaks were placed in groups of 4 (for slaughter group 1, n = 18, and for slaughter group 2, n = 25) containing 1 randomly selected representative steak from each of the 4 treatments. To evaluate muscle color only, panelists were asked to choose 1 steak from each group that they would most likely purchase (panelists were requested to select 1 steak from each group for each aging period) and to place an X through any steaks they deemed unacceptable for retail display. Steak evaluation by consumer panelists was done at 72 and 144 h in retail

3771Finishing diet on beef quality

display. The overall acceptability of each steak for each aging period was averaged (0 = steak was neither cho-sen for purchase nor deemed unacceptable, 1 = steak was chosen for purchase, and 2 = steak was deemed unacceptable) for a final acceptability value.

WBSF

Steaks designated for objective tenderness were re-moved from the freezer and allowed to thaw at 4°C for 24 h before cooking. The steaks were then cooked on an

impingement oven (XLT Ovens, Model 3240TS2, BOFI, Wichita, KS) to an internal temperature of 70°C. Once steaks were cooked, they were chilled at 4°C for another 24-h period. To determine WBSF, 6 cores (1.27 cm in diameter) were taken from each steak parallel to the muscle fiber orientation. Cores were sheared once us-ing an Instron Universal Testing Machine (Model 4502, Instron Corp., Canton, MA) with a Warner-Bratzler head at a speed of 200 mm/min. Peak force (kg) of the cores was recorded using an IBM Personal System/2 computer (Model 55SX) equipped with software sup-

Table 1. Least squares means for carcass traits by vitamin E dietary supplementation treatment (n = 199)

Item

Treatment (vitamin E supplementation)

SEMControl 125 IU∙animal−1∙d−1 250 IU∙animal−1∙d−1 500 IU∙animal−1∙d−1

HCW, kg 399.62 394.42 400.57 408.41 6.30Fat thickness, cm 1.41 1.38 1.45 1.45 0.07LM area, cm2 91.46 92.04 95.65 95.65 2.60KPH, % 2.28 2.32 2.48 2.48 0.07Marbling score1 43.77 42.10 43.42 43.42 0.96

1Marbling score: 10 = practically devoid; 20 = traces; 30 = slight; 40 = small; 50 = modest; 60 = moderate.

Table 2. Least squares means for muscle color1 scores given to MAP-packaged2 (n = 185) and PVC-packaged3 (n = 185) strip loin steaks throughout a 7-d period in the retail display case

Item



MAP package, h 0 3.31b 3.14a 2.97a 2.98a 0.05 12 3.51b 3.48b 3.25a 3.24a 0.04 24 3.62b 3.60b 3.32a 3.33a 0.03 36 3.75b 3.79b 3.49a 3.45a 0.04 48 4.02b 4.17b 3.76a 3.58a 0.07 60 4.46b 4.17b 3.83a 3.66a 0.09 72 4.64b 4.51b 4.21a 3.91a 0.06 84 4.68b 4.62b 4.17a 4.09a 0.05 96 5.35c 4.82b 4.23a 4.06a 0.11 108 4.96b 5.21b 4.45a 4.29a 0.08 120 5.41b 5.35b 4.84a 4.65a 0.05 132 5.79b 5.47b 4.98a 4.73a 0.09 144 5.84 5.69 5.72 5.08a 0.11 156 6.17 5.92c 5.54b 5.14a 0.06PVC package, h 0 3.24 3.22 3.11 3.14 0.05 12 3.29 3.25 3.12 3.20 0.03 24 3.41 3.39 3.28 3.28 0.03 36 3.54 3.53 3.39 3.52 0.03 48 3.85 3.80 3.62 3.68 0.03 60 4.05 4.05 3.85 3.89 0.04 72 4.14b 4.11b 3.84a 3.85a 0.04 84 4.29b 4.22b 4.00a 4.02a 0.04 96 4.53b 4.47b 4.21a 4.22a 0.04 108 4.78b 4.61b 4.27a 4.32a 0.05 120 5.00b 4.88b 4.47a 4.52a 0.05 132 5.26b 5.08b 4.68a 4.62a 0.06 144 5.55b 5.36b 5.03a 4.86a 0.06 156 6.04b 5.83a 5.53a 5.32a 0.06

a–cMeans in the same row without a common superscript are different (P < 0.05).1Muscle color was measured on an 8-point scale (1 = very bright red or pinkish red, and 8 = tan to brown).2Modified atmosphere package (75% O2 and 25% CO2).3Polyvinyl chloride overwrapped package.


plied by the Instron Corporation. Peak WBSF values of the 6 cores were averaged for a final tenderness value.

Sensory Evaluation

Steaks designated for sensory evaluation were re-moved from the freezer, assigned a random number, and allowed to thaw at 4°C for 24 h before cooking. All steaks were cooked using the same method as described for WBSF. After cooking, steaks were cut into 1 × 1 × 2.54 cm samples. Samples were placed into plastic cups that were marked with a number corresponding to that designated for the steaks at the time of tempering. The cups were then placed into individual warmers with heat pads to keep the samples warm throughout the evaluation session.

The panel was made up of 8 Oklahoma State Univer-sity personnel who were trained in accordance with the “Guidelines for Training and Testing Judges for Sensory Analysis of Meat Quality” (Cross et al., 1978). Sessions were held in a temperature- and light-controlled room in which panelists were randomly seated at individual booths and served samples under red lights to avoid visual bias. Twelve samples were served at each session

in a random order. Up to 4 sessions were held a day, 2 in the morning and 2 in the afternoon, and each session was separated by at least a 10-min break. Panelists were also supplied with distilled, deionized water and unsalted crackers for palate cleansing between samples. Steaks were evaluated for initial and sustained juiciness (8 = extremely juicy, and 1 = extremely dry), initial and overall tenderness (8 = extremely tender, and 1 = extremely tough), and amount of connective tissue (8 = none, and 1 = abundant). If off-flavors were detected, panelists recorded this in a comment column, but there was no scale and no specific attributes were evaluated.

TBARS

Product designated for one of the multiple sampling periods for TBARS testing were removed from the freezer and allowed to thaw for 24 h at 4°C before lipid peroxidation was performed by a method modified from Buege and Aust (1978). A 10-g sample was removed from each steak and placed in a Waring blender (Model 51BL31, Waring, Torrington, CT) to be homogenized with 30 mL of deionized water. That sample was then transferred into a disposable test tube and centrifuged

Table 3. Least squares means for muscle discoloration1 values given to MAP-packaged2 (n = 185) and PVC-packaged3 (n = 185) strip loin steaks throughout a 7-d period in the retail display case

Item



MAP package, h 12 1.02 1.05 1.02 1.03 0.008 24 1.04 1.08 1.02 1.03 0.009 36 1.10 1.16 1.02 1.06 0.02 48 1.26a 1.33b 1.05a 1.18a 0.03 60 1.46b 1.53b 1.16a 1.23a 0.04 72 1.42b 1.28b 2.07a 2.02a 0.07 84 2.42b 2.33b 1.36a 1.43a 0.09 96 3.22b 2.95b 1.61a 1.61a 0.11 108 3.76b 3.40b 1.93a 1.79a 0.12 120 4.42b 4.07b 2.53a 2.17a 0.13 132 4.78b 4.60b 2.85a 2.31a 0.14 144 5.05c 4.86c 3.18b 2.42a 0.14 156 5.43 5.31c 4.00b 2.71a 0.15PVC package, h 12 1.05 1.03 1.03 1.03 0.007 24 1.08 1.09 1.14 1.11 0.02 36 1.22 1.23 1.21 1.25 0.02 48 1.26 1.30 1.29 1.29 0.01 60 1.39 1.46 1.38 1.41 0.02 72 1.54 1.53 1.47 1.50 0.02 84 1.63 1.61 1.53 1.60 0.03 96 1.89 1.78 1.69 1.77 0.03 108 2.42 2.40 2.22 2.26 0.04 120 2.53 2.41 2.33 2.25 0.05 132 3.00 2.79 2.91 2.59 0.07 144 3.42b 3.28b 3.33b 2.75a 0.09 156 1.81 1.74 2.73 3.73 0.10

a–cMeans in the same row without a common superscript are different (P < 0.05).1All percentages of muscle discoloration were measured on a 7-point scale (1 = no discoloration or 0%, and 7 = total discoloration or 100%).2Modified atmosphere package (75% O2 and 25% CO2).3Polyvinyl chloride overwrapped package.


at 1,854.7 × g and 2°C for 10 min. A 2-mL quantity of the supernatant was then extracted and combined in a disposable glass test tube with 4 mL of thiobarbituric acid/trichloroacetic acid and 100 μL of butylated hy-droxyanisol. The combination was then vortexed before allowing it to sit in a boiling water bath for 15 min to develop color, and the sample was then placed in a cold water bath for 10 min to allow it to cool. Once complete, the mixtures were centrifuged again at 1,854.7 × g and 2°C for 10 min. The absorbance of these supernatants was analyzed at 531 nm in comparison with standards developed each day. The average of the 2 supernatants, per sample, was used for statistical analysis.

Proximate Analysis

Samples for proximate analysis were stored in Whirl-Pak bags and allowed to thaw using the methods previ-ously mentioned for WBSF. Once samples were thawed, they were powder homogenized with the use of a War-ing blender (Model 51BL31, Waring) and two 1- to 3-g samples were secured in filter paper (15 cm, Whatman No. 41, Whatman International, Maidstone, UK) with a

smooth paper clip. Secured samples were then placed in a 102°C oven for 24 h, with weighing done both before and after heating (sample, paper, and clip). Once the samples were removed and allowed to cool for approxi-mately 45 min, they were placed in a Soxhlet unit, in which heated petroleum ether drips through the sample for a 24-h period, extracting fat. Samples were then dried for approximately 20 min before being placed in a desiccator to cool. Once cool, samples were reweighed for final lipid content by using procedures of AOAC (1990). Weights taken before and after initial heating were averaged and used to determine a final moisture content value, whereas final weights after ether extrac-tion and drying were averaged for a final lipid content value. Samples were analyzed for protein by using the combustion method of AOAC (1990).

Statistical Analysis

Data for both steaks and ground beef were analyzed using the MIXED procedure (SAS Inst. Inc., Cary, NC). Data were analyzed as a completely randomized split-plot design, with animal as the experimental unit

Table 4. Least squares means for overall acceptability1 values given to MAP-packaged2 (n = 185) and PVC-packaged3 (n = 185) strip loin steaks throughout a 7-d period in the retail display case

Item



MAP package, h 0 6.98b 6.97b 7.14a 7.11a 0.03 12 6.73b 6.68b 6.94a 6.88a 0.03 24 6.26b 6.36b 6.62a 6.58a 0.03 36 6.10b 6.04b 6.43a 6.42a 0.04 48 5.97a 5.84b 6.29a 6.51a 0.09 60 5.51b 5.49b 6.17a 6.20a 0.09 72 4.50b 4.61b 5.66a 5.66a 0.09 84 4.17b 4.28b 5.51a 5.57a 0.10 96 3.56b 6.69b 5.31a 5.46a 0.12 108 3.16b 3.33b 4.96a 4.99a 0.12 120 2.73b 2.76b 4.20a 4.70a 0.12 132 2.28c 2.36c 3.84b 4.43a 0.12 144 2.02c 2.16c 3.38b 4.16a 0.12 156 1.81 1.74c 2.73b 3.73a 0.11PVC package, h 0 6.86 6.77 6.88 6.83 0.07 12 6.89 6.82 7.01 6.83 0.06 24 6.51 6.44 6.61 6.71 0.07 36 6.32 6.19 6.40 6.24 0.05 48 6.01 5.96 6.18 6.04 0.05 60 5.81 5.75 6.02 5.83 0.05 72 5.84b 5.76b 6.12a 6.01a 0.05 84 5.59 5.64 5.95 5.80 0.05 96 5.18b 5.30b 5.65a 5.56a 0.06 108 4.75b 4.97b 5.40a 5.28a 0.07 120 4.31 4.57 4.68 4.90 0.08 132 3.18b 3.51b 3.98a 4.21a 0.09 144 2.52b 2.85b 3.23a 3.60a 0.09 156 2.13b 2.30b 2.62a 2.86a 0.09

a–cMeans in the same row without a common superscript are different (P < 0.05).1Overall acceptability was measured on an 8-point scale (8 = extremely desirable/acceptable, and 1 = extremely undesirable/unacceptable).2Modified atmosphere package (75% O2 and 25% CO2).3Polyvinyl chloride overwrapped package.


and strip loin or chuck being the split plot. The ANO-VA model used to analyze carcass data, WBSF, senso-ry data, TBARS, objective color attributes, subjective color attributes, and proximate analysis included treat-ment as the fixed effect and strip or chuck identifica-tion as the random effect. All color data were analyzed by package type and hour of evaluation. The ANOVA repeated-measures model was used for subjective and objective color attributes, using strip or chuck as the subject and treatment as the fixed effect. When the main effects were significant (α = 0.05) or approached significance (0.05 < P < 0.10), least squares means were computed and statistically separated by pairwise t-test. Consumer purchase preference and consumer ac-ceptability were analyzed using χ2 frequencies. The fre-quencies were deemed significant when P < 0.05.

RESULTS AND DISCUSSION

Carcass Data

Results for the effects of supplementation on carcass characteristics are presented in Table 1. There were no

differences in carcass characteristics among all treat-ment groups (P > 0.10). This is supported by results from Arnold et al. (1992), who also recognized that vitamin E supplementation affected neither feedlot per-formance or carcass characteristics, including quality and yield grades.

Color Evaluation

Subjective color evaluations from the trained color panel for MAP-packaged steaks can be found in Tables 2, 3, and 4. An evident difference in color was detect-ed throughout almost the entire retail display period (P < 0.05). At 0 h, panelists recorded that only the steaks from the CON diet were a duller red color than the other treatment groups, whereas from 12 through 132 h, the steaks from the 500 and 250 IU∙animal−1∙d−1 groups were brighter than those from the CON and 125 IU∙animal−1∙d−1 groups (P < 0.05). At 156 h, steaks from the 500 IU∙animal−1∙d−1 group were redder than those from the 250 IU∙animal−1∙d−1 group, and those from the 250 IU∙animal−1∙d−1 treatment were redder

Table 5. Least squares means for muscle color1 scores given to MAP-packaged2 (n = 69) and PVC-packaged3 (n = 69) ground beef throughout a 7-d period in the retail display case

Item



MAP package, h 0 2.14 2.24 2.25 2.22 0.06 12 2.61 2.68 2.88 2.81 0.07 24 2.76 2.82 2.85 2.94 0.06 36 3.08 3.19 3.23 3.30 0.05 48 3.46 3.61 6.62 6.57 0.05 60 3.74 4.03 4.13 4.00 0.07 72 3.90b 4.41b 4.63a 4.28a 0.08 84 4.32 4.77 4.70 4.42 0.08 96 4.84 5.33 5.07 4.91 0.09 108 5.26 5.59 5.24 5.01 0.09 120 5.60 5.92 5.68 5.29 0.10 132 5.94 6.22 5.91 5.37 0.13 144 6.07 6.36 5.99 5.52 0.12 156 6.31b 6.56b 5.97a 5.50a 0.13PVC package, h 0 1.81 1.74 2.01 2.07 0.05 12 2.21b 2.18b 2.58a 2.57a 0.06 24 2.19 2.54 2.62 2.66 0.08 36 2.77 2.64 2.89 2.89 0.06 48 2.75b 2.81b 3.03a 3.22a 0.07 60 3.42 2.88 3.25 3.17 0.13 72 3.16 3.18 3.51 3.38 0.08 84 3.46 3.46 3.61 3.54 0.07 96 3.56 3.58 3.63 3.60 0.07 108 4.01 4.22 4.25 4.17 0.09 120 4.67 5.07 4.94 4.63 0.09 132 5.00 5.63 5.23 5.11 0.11 144 5.55 6.12 5.52 5.28 0.13 156 5.94 6.71 6.14 5.79 0.15

a,bMeans in the same row without a common superscript are different (P < 0.05).1Muscle color was measured on an 8-point scale (1 = very bright red or pinkish red, and 8 = tan to brown).2Modified atmosphere package (75% O2 and 25% CO2).3Polyvinyl chloride overwrapped package.


than those from the 125 IU∙animal−1∙d−1 and CON treatments (P < 0.05).

Discoloration and overall acceptability of steaks in MAP packages showed that after 36 h in retail display, although there was a distinct difference (P < 0.05) be-tween the greater supplementation (500 IU∙ and 250 IU∙animal−1∙d−1) and the lesser supplementation (125 IU∙animal−1∙d−1 and CON; Tables 3 and 4). These re-sults corresponded to those of Arnold et al. (1992), who reported that, in general, the greater the amount of vitamin E fed, the longer the supplementation, or both, the longer the meat would last in retail display.

Differences in color for PVC overwrapped steaks did not become apparent until approximately 72 h in the retail display (P < 0.05; Table 2). In terms of discol-oration (Table 3), the PVC overwrapped steaks stayed statistically consistent until 144 h in display. At that point, steaks from the diets providing more vitamin E (500 and 250 IU∙animal−1∙d−1) had less discolor-ation (P < 0.05) than those from diets with decreased amounts of vitamin E (125 IU∙animal−1∙d−1 and CON). Least squares means (Table 4) indicate that panel-ists thought PVC-packaged steaks, as a whole, were

deemed slightly undesirable after 120 h in retail dis-play (P = 0.08).

Steaks packaged in both MAP and PVC were col-or scored for the duration of retail display. At 108 h, PVC-packaged strip steaks were all considered slightly discolored (1 to 19%), whereas MAP-packaged strip steaks were not all deemed slightly discolored until 120 h. Zerby et al. (1999) reported that, in retail, meat should be discounted at more than 10% discoloration. This suggests that MAP packaging may be preferred for retention of product in the retail display.

Ground beef in MAP packages remained consistent in terms of darkening (Table 5) until 156 h of retail display, at which there was a significant difference be-tween the supplementation of 500 IU∙animal−1∙d−1 and the supplementation of less dietary vitamin E (P < 0.05). After approximately 84 h in display, the discol-oration and overall acceptability of ground beef (Tables 6 and 7) between animals fed the greater vitamin E in the diet (500 and 250 IU∙animal−1∙d−1) and those re-ceiving less supplementation (125 IU∙animal−1∙d−1 and CON) were significantly different (P < 0.05). Ground beef in PVC overwrapped packages (Tables 5, 6, and

Table 6. Least squares means for percentage of muscle discoloration1 values given to MAP-packaged2 (n = 69) and PVC-packaged3 (n = 69) ground beef throughout a 7-d period in the retail display case

Item



MAP package, h 12 1.00 1.00 1.00 1.00 0.00 24 1.00 1.00 1.00 1.00 0.00 36 1.01 1.01 1.06 1.02 0.01 48 1.23 1.31 1.37 1.35 0.02 60 1.44 1.57 1.72 1.36 0.06 72 1.82 2.11 2.02 1.58 0.09 84 2.19 2.72 2.36 1.79 0.12 96 2.89a 3.43b 2.95a 2.04a 0.17 108 3.46b 3.94c 3.18b 2.32a 0.19 120 3.85b 4.30c 3.51b 2.52a 0.21 132 4.31c 4.73c 3.88b 2.76a 0.22 144 4.65c 4.85c 4.12b 2.92a 0.22 156 5.18c 5.23c 4.61b 3.15a 0.23PVC package, h 12 1.66 1.77 1.93 1.82 0.04 24 1.75 1.78 1.93 2.01 0.04 36 1.81 1.80 1.99 2.07 0.04 48 1.85 1.84 2.24 2.02 0.07 60 1.92b 1.82b 2.14a 2.13a 0.05 72 1.95 1.90 2.11 2.07 0.05 84 2.28 2.48 2.34 2.26 0.06 96 2.21 2.46 2.33 2.30 0.07 108 2.56 3.29 2.57 2.58 0.11 120 3.52b 4.43c 3.66b 2.82a 0.15 132 4.03b 5.01c 4.30b 3.26a 0.18 144 4.40b 5.40c 4.73b 3.85a 0.20 156 4.82 5.25 5.95 4.82 0.18

a–cMeans in the same row without a common superscript are different (P < 0.05).1Muscle discoloration was measured on a 7-point scale (1 = no discoloration or 0%, and 7 = total discoloration or 100%).2Modified atmosphere package (75% O2 and 25% CO2).3Polyvinyl chloride overwrapped package.


7) resulted in some differences during retail display (P < 0.05), but at 156 h, no differences were reported for muscle color, discoloration, or overall acceptability among treatment groups.

Instrumental color evaluation of strip steaks measured no significant differences among dietary treatment for L* values for both MAP-packaged and PVC overwrap-packaged steaks (Table 8) throughout the entire retail display period. Table 8 shows that, with the exception of 12-h PVC overwrapped steaks, a* measurements for MAP-packaged (P < 0.05) and PVC-packaged steaks (P < 0.05) were significantly different throughout the extent of retail display. These results indicate that steaks from animals receiving greater vitamin E supple-mentation in the diet (500 and 250 IU∙animal−1∙d−1) re-tained redness for a longer period when compared with animals receiving less vitamin E supplementation (125 IU∙animal−1∙d−1 and CON). All b* measurements for MAP-packaged strip steaks, and those at 60 and 156 h for PVC overwrapped-packaged steaks were significant-ly greater for treatments with animals receiving 500

and 250 IU∙animal−1∙d−1 than those for treatments with animals receiving 125 IU∙animal−1∙d−1 and CON. These results suggest that greater vitamin E supplementation in a distillers grain-based diet enhances the retention of yellowness during the retail display period. Aside from vector angle, these results correspond to those of Liu et al. (1996), who declared that muscle α-tocopherol accumulation from dietary supplementation caused the retention of redness and yellowness of the LM, indicat-ing that increased vitamin E supplementation of ani-mals was necessary to detect an improvement in color display life of LM.

Instrumental analysis of ground beef indicated no significant difference for L* and b* measurements for both MAP and PVC overwrap packages at 0 and 156 h (Table 9). The a* values recorded for 156-h MAP-packaged and 0- and 72-h PVC-packaged ground beef indicated a difference (P < 0.05). These data indicated that supplementing 500 IU∙animal−1∙d−1 enhanced the retention of redness in ground beef better than supple-menting less vitamin E. Differences among objective

Table 7. Least squares means for overall acceptability1 values given to MAP-packaged2 (n = 69) and PVC-pack-aged3 (n = 69) ground beef throughout a 7-d period in the retail display case

Item



MAP package, h 0 7.47 7.42 7.37 7.37 0.04 12 7.36 7.22 7.17 7.15 0.05 24 7.53 7.38 7.41 7.38 0.04 36 7.32 7.13 7.18 7.21 0.04 48 7.06 6.83 6.83 6.85 0.05 60 6.00a 5.67b 5.38b 5.83a 0.08 72 5.32a 4.62b 4.56b 5.33a 0.10 84 4.82a 4.08b 4.30b 4.92a 0.12 96 4.13a 3.27b 3.90b 4.46a 0.15 108 3.58b 2.80c 3.68b 4.23a 0.16 120 3.24b 2.51c 3.38b 4.13a 0.18 132 2.79b 2.33c 3.03b 3.84a 0.18 144 2.57b 2.10b 2.87b 3.66a 0.17 156 2.25b 2.01b 2.61b 3.39a 0.17PVC package, h 0 7.50 7.42 7.31 7.36 0.04 12 7.02 7.01 6.70 6.79 0.06 24 6.91 6.81 6.70 6.49 0.07 36 6.58 6.66 6.36 6.23 0.07 48 6.52b 6.45b 6.23b 5.98a 0.07 60 6.17 6.14 5.72 5.67 0.09 72 5.80 5.88 5.48 5.42 0.09 84 5.30 5.11 5.19 5.30 0.09 96 4.89 4.69 4.80 4.78 0.11 108 4.33 3.72 4.32 4.38 0.12 120 3.59b 2.62c 3.34b 4.01a 0.15 132 3.00a 2.03b 2.75b 3.37a 0.17 144 2.56 1.83 2.43 2.91 0.18 156 2.13 1.29 1.96 2.17 0.16

a–cMeans in the same row without a common superscript are different (P < 0.05).1Overall acceptability was measured on an 8-point scale (8 = extremely desirable/acceptable, and 1 = extremely undesirable/unacceptable).2Modified atmosphere package (75% O2 and 25% CO2).3Polyvinyl chloride overwrapped package.


measurement values were not significant (P > 0.10), suggesting that vitamin E supplementation did not in-crease retail shelf life in ground beef.

Consumer evaluations of muscle color for strip steaks in both MAP and PVC overwrap packages indicated that dietary treatment had an effect on retail selection of product (Table 10). Differences were not observed for PVC overwrapped packages after 3 d of evaluation. However, it was evident that greater vitamin E supple-mentation were beneficial (500 IU∙animal−1∙d−1) in a distillers grain-based diet for 7-d PVC because 40.7% would be more likely to purchase steaks from cattle fed 500 IU∙animal−1∙d−1. Product packaged in MAP for 3 and 7 d from animals that had been supplemented with 250 or 500 IU∙animal−1∙d−1 was more often ac-ceptable to consumers and more frequently chosen for purchase than steaks from cattle supplemented at de-creased amounts. The evaluations of this panel were

based strictly on muscle color and amount of discol-oration, implying that greater vitamin E in distillers grain-based diets is suggested for consumer acceptance throughout the duration of retail display.

Sensory Attributes

Objective tenderness measurements and subjective sensory evaluations (Table 11) generally showed no differences among treatment groups in juiciness, ten-derness, and amount of connective tissue (P > 0.10). All steaks used for these measurements were stored in MAP packages; therefore, no package interactions were evaluated. Warner-Bratzler shear force values were on average 3.83 ± 0.1 units among all treatments, which were still less than the suggested consumer threshold of 3.9 to 4.6 kg, the threshold for “slightly tender” beef, as reported by Shackelford et al. (1991). These results

Table 8. Least squares means for the L*, a*, and b* values1 of MAP-packaged2 (n = 185) and PVC-packaged3 (n = 185) strip loins throughout a 7-d period in the retail display case

Item



L* MAP package, h 12 41.61 41.96 41.99 43.23 0.28 60 42.61 42.48 42.93 43.28 0.18 156 45.69 45.11 43.87 43.38 0.23 PVC package, h 0 37.71 37.58 37.86 38.05 0.20 12 38.03 38.16 38.30 38.52 0.20 60 38.02 38.15 38.26 38.71 0.21 108 38.54 38.73 38.70 38.87 0.21 156 38.37 39.05 39.06 39.07 0.26a* MAP package, h 12 23.15 23.46 24.08 24.05 0.12 60 18.49 19.04 20.79 20.63 0.25 156 8.88 8.71 2.92 16.38 0.42 PVC package, h 0 23.14 23.08 22.99 22.27 0.13 12 23.26 23.09 23.61 23.18 0.11 60 20.61 20.69 22.02 21.43 0.15 108 15.10 16.06 16.26 17.44 0.28 156 12.69 15.50 17.33 17.31 0.39b* MAP package, h 12 18.77b 19.05a 19.23a 19.36a 0.07 60 16.56b 16.86b 17.64a 17.72a 0.12 156 14.51c 14.50c 15.06b 16.22a 0.13 PVC package, h 0 19.07 19.07 18.74 18.58 0.10 12 19.32 19.32 19.68 19.38 0.10 60 18.18a 18.33a 19.16b 18.64a 0.11 108 15.95 16.50 16.59 16.84 0.13 156 15.15b 16.27a 16.96a 16.83a 0.16

a–cMeans in the same row without a common superscript are different (P < 0.05).1The L* values were used to measure brightness (brightness: 0 = black and 100 = white). The a* values were used to measure redness/greenness

(redness/greenness: positive values = red, and negative values = green). The b* values were used to measure yellowness/blueness (yellowness/blueness: positive values = yellow, and negative values = blue).

2Modified atmosphere package (75% O2 and 25% CO2).3Polyvinyl chloride overwrapped package.


are supported by multiple authors (Arnold et al., 1992; Brandt et al., 1992; Koger et al., 2004) who also re-ported no differences in WBSF between animals fed diets differing in inclusion amounts of vitamin E or distillers grains. These objective measurements are sup-ported by the results of the trained panel. Although overall tenderness was consistently numerically greater for those diets with an inclusion level of 250 and 500 IU∙animal−1∙d−1 of vitamin E, no significant differences (P > 0.10) were detected. As also reported by Arnold et al. (1992), Roeber et al. (2005), and Gill et al. (2008), no differences were observed in juiciness and connec-tive tissue among the different treatments. These data suggest that different inclusion amounts of vitamin E in a distillers grain-based diet will not affect sensory attributes.

TBARS

Least squares means for TBARS measurements in strip steaks are presented in Table 12. Dietary treat-ment did not have an effect on lipid oxidation, as in-dicated by the TBARS concentrations in steaks that were vacuum packaged on absolute 0 d. However, those steaks that were packaged in PVC overwrap and MAP

packages showed significant differences in lipid oxida-tion for 7 d in PVC (P < 0.05) and for 1, 3, and 7 d in MAP (P < 0.05). It was also evident that those steaks in MAP packages oxidized at a faster rate under retail display conditions than those in PVC overwrap packag-es. Campo et al. (2006) reported that a TBARS value of 2.28 mg/kg was the limiting threshold for consumer acceptability of oxidation and that in terms of sensory attributes, rancidity overpowered the beef flavor. The present study indicated that steaks from the CON and 125 IU∙animal−1∙d dietary treatments in MAP pack-ages surpassed this threshold at 7 d in a retail display, and would be deemed unacceptable. However, steaks from all other aging periods and packaging methods remained below this threshold.

Dietary treatment did have an effect on lipid oxi-dation, as indicated by the TBARS concentrations of ground beef vacuum packaged on absolute 0 d, and the product in PVC overwrap and MAP packages that were placed under simulated retail display conditions for 7 d (Table 13). For 0 d, the greater supplementa-tion of vitamin E in the diets resulted in product with greater amounts of lipid oxidation compared with prod-uct from animals fed the 125 IU∙animal−1∙d−1 and CON diets (P < 0.05). Throughout the duration of retail

Table 9. Least squares means for the L*, a*, and b* values1 of MAP-packaged2 (n = 69) and PVC-packaged3 (n = 69) ground beef throughout a 7-d period in the retail display case

Item



L* MAP package, h 12 39.87 41.19 40.20 39.39 0.40 156 38.24 36.92 37.58 36.65 0.44 PVC package, h 0 48.55 48.33 46.96 46.77 0.38 72 46.19 46.45 45.06 44.08 0.42 156 40.20 41.29 40.03 39.45 0.43a* MAP package, h 12 22.98 22.33 23.03 22.77 0.19 156 12.23b 12.09b 12.83b 15.78a 0.48 PVC package, h 0 24.06b 23.56c 24.96b 25.09a 0.22 72 11.78b 9.90c 11.81b 13.60a 0.39 156 21.97 22.45 22.42 23.07 0.29b* MAP package, h 12 19.62 19.41 19.69 19.39 0.07 156 15.05 14.71 15.30a 15.75 0.15 PVC package, h 0 18.78 18.16 18.76 18.36 0.16 72 13.62a 12.50b 13.55a 13.96a 0.17 156 19.11 19.48 19.29 19.58 0.14

a–cMeans in the same row without a common superscript are different (P < 0.05).1The L* values were used to measure brightness (brightness: 0 = black, and 100 = white). The a* values were used to measure redness/greenness

(redness/greenness: positive values = red, and negative values = green). The b* values were used to measure yellowness/blueness (yellowness/blueness: positive values = yellow, and negative values = blue).

2Modified atmosphere package (75% O2 and 25% CO2).3Polyvinyl chloride overwrapped package.


Table 10. Effects of packaging on consumer acceptability and purchase preference percentage of steaks from cattle supplemented with vitamin E1

Item



PVC2 package, % Purchase d 3 23.2bc 23.3bc 28.5b 24.9b 0.04 Purchase d 7 11.5d 18.7c 29.0b 40.7a 0.03 Acceptable d 3 70.8a 69.5a 75.4a 68.5a 0.02 Acceptable d 7 16.6b 15.5b 16.8b 18.1b 0.04MAP3 package, % Purchase d 3 18.2c 20.5c 30.9b 30.5b 0.03 Purchase d 7 6.9d 10.9d 30.3a 51.9a 0.07 Acceptable d 3 42.1b 46.1b 61.9a 55.5a 0.03 Acceptable d 7 11.9d 11.6d 23.1 26.2 0.04

a–dPercentages in the same package type and purchase of acceptability decision category without a common superscript are different (P < 0.05).1Mean values for consumer color scores: 0 = steak was neither chosen for purchase nor deemed unacceptable, 1 = steak was chosen for purchase,

and 2 = steak was deemed unacceptable.2Polyvinyl chloride overwrapped package.3Modified atmosphere package (75% O2 and 25% CO2).

Table 11. Least squares means for objective tenderness (n = 185) and sensory attributes (n = 185) of MAP-packaged1 strip steaks that remained under retail display for 72 h

Item



Juiciness Initial 4.92 4.87 4.97 5.10 0.07 Sustained 5.38 5.32 5.49 5.55 0.07Tenderness Initial 5.71 5.69 5.76 5.89 0.10 Overall 5.69 5.63 5.72 5.83 0.10Connective tissue 5.78 5.69 5.84 5.91 0.09WBSF,2 kg 3.91 3.74 3.77 3.90 0.11

1Modified atmosphere package (75% O2 and 25% CO2).2Warner-Bratzler shear force after 72 h in retail display.

Table 12. Least squares means for thiobarbituric acid reactive substances (mg of malonaldehyde/kg of beef) in strip loins (n = 185), evaluated predisplay and at 7 d of retail display for PVC1 packages, and at 1, 3, and 7 d for MAP2 packages

Item



Vacuum package Absolute d 0 0.3676 0.3709 0.3158 0.3142 0.03PVC package d 7 1.0311b 0.9990b 0.7909ab 0.5699a 0.10MAP package d 1 1.1758b 1.2106b 0.8481a 0.6490a 0.07 d 3 2.3400c 2.2220c 1.6909b 1.3396a 0.09 d 7 3.1023c 3.0881c 2.2912b 1.6610a 0.11

a–cMeans in the same row without a common superscript are different (P < 0.05).1Polyvinyl chloride overwrapped package.2Modified atmosphere package (75% O2 and 25% CO2).


display, however, the greater vitamin E in the diet oxi-dized product at a slower rate, maintaining a reduced amount of oxidation. These significant differences sug-gest that 500 IU∙animal−1∙d−1 will result in a decreased amount of lipid oxidation in ground beef compared with diets supplemented with less vitamin E.

Proximate Analysis: Ground Beef

Least squares means are included for the amounts of fat, moisture, and protein measured in the ground beef among treatment groups. Because fabrication was done at the plant, to meet IMPS #116A, the amount of external fat was not altered before grinding. There-fore, the amount of fat in the mixture may vary be-cause of differences in trim levels. The amount of fat ranged from 7.03 to 23.07%, the amount of moisture ranged from 60.47 to 74.37%, and the amount of pro-tein ranged from 13.56 to 24.14%. Although the data suggest that greater amounts of vitamin E in the diet tend to increase the amount of moisture and decrease the amounts of fat and protein, no significant differ-ences (P > 0.10) were detected for percentages of fat, moisture, and protein among the different treatment groups.

Conclusions

Results of this study indicate that the inclusion of different amounts of vitamin E in a distillers grain-based diet will not have an effect on carcass charac-teristics and sensory attributes. This study does indi-cate that to maximize retail shelf life and decrease lipid oxidation, the critical dietary supplementation is 500 IU∙animal−1∙d−1 of vitamin E in a 35% wet distillers grain-based diet (DM basis) for at least 97 d before slaughter. It is evident that greater vitamin E supple-mentation in the diet aids in the maintenance of shelf stability for MAP- and PVC-packaged strip steaks by sustaining muscle color and overall acceptability while decreasing the percentage of discoloration by decreas-ing the rate at which lipid oxidation occurs throughout a 156-h period. Considering package type, MAP seems

to maintain color for a longer period, indicating it would be the preferred packaging for longer aging peri-ods. Instrumental color measurements also showed that although brightness was not improved, greater dietary vitamin E maintained the redness and yellowness of steaks for a longer time. It is apparent that greater vi-tamin E in the diet decreases lipid oxidation in ground beef, yet it has little effect on shelf stability and objec-tive color measurements. Ultimately, the inclusion of vitamin E in distillers grain-based diets for beef cattle, and beef processed for retail in MAP packaging, should maximize retail shelf life and decrease the loss of profit caused by lipid oxidation and discoloration.

LITERATURE CITED

American Meat Science Association. 1991. Guidelines for meat color evaluation. Pages 1–17 in Proc. 44th Reciprocal Meat Conf., Manhattan, KS. Am. Meat Sci. Assoc., Natl. Livest. Meat Board, Chicago, IL.

AOAC. 1990. Official Methods of Analysis of the Association of Of-ficial Analytical Chemists. Vol. II. 15th ed. Sec. 985.29. Assoc. Off. Anal. Chem., Arlington, VA.

Arnold, R. N., K. K. Scheller, S. C. Arp, S. N. Williams, D. R. Buege, and D. M. Schaefer. 1992. Effect of long- or short-term feeding of α-tocopherol acetate to Holstein and crossbred beef steers on performance, carcass characteristics, and beef color stability. J. Anim. Sci. 70:3055–3065.

Baker, A., and S. Zahniser. 2006. Ethanol reshapes the corn market. Amber Waves. 4:30–36.

Brandt, R. T. Jr., G. L. Kuhl, R. E. Campbell, C. L. Kastner, and S. L. Stroda. 1992. Effects of steam-flaked sorghum grain or corn and supplemental fat on feedlot performance, carcass traits, longissimus composition, and sensory properties of steers. J. Anim. Sci. 70:343–348.

Buege, J. A., and S. D. Aust. 1978. Microsomal lipid peroxidation. Methods Enzymol. 52:302–310.

Campo, M. M., G. R. Nute, S. I. Hughes, M. Enser, J. D. Wood, and R. I. Richardson. 2006. Flavour perception of oxidation in beef. Meat Sci. 72:303–311.

CIE (Commission Internationale de l’Éclairage). 1976. Recommen-dations on uniform color spaces—Color difference equations, psychometric color terms. Suppl. No. 2 to CIE Publ. No. 15 (E-1.3.1) 1971. Commission Internationale de l’Éclairage, Paris, France.

Cross, H. R., R. Moen, and M. S. Stanfield. 1978. Training and testing of judges for sensory analysis of meat quality. Food Technol. 32:48–54.

Table 13. Least squares means for thiobarbituric acid reactive substances in ground beef (mg of malonaldehyde/kg of beef), evaluated predisplay and on d 7 of retail display for PVC1 and MAP2 packages

Item



Vacuum package Absolute d 0 0.3417c 0.4958b 0.8131a 0.6011a 0.07PVC package d 7 2.7490b 2.4462b 2.2853b 0.9512a 0.25MAP package d 7 1.2092b 1.1023b 0.9449b 0.4804a 0.13

a–cMeans in the same row without a common superscript are different (P < 0.05).1Polyvinyl chloride overwrapped package.2Modified atmosphere package (75% O2 and 25% CO2).


Faustman, C., W. K. Chan, D. M. Schaefer, and A. Havens. 1998. Beef color update: The role for vitamin E. J. Anim. Sci. 76:1019–1026.

Gill, R. K., D. L. VanOverbeke, B. Depenbusch, J. S. Drouillard, and A. DiCostanzo. 2008. Impact of beef cattle diets containing corn or sorghum grains on beef color, fatty acid profiles, and sensory attributes. J. Anim. Sci. 86:923–935.

Koger, T. J., D. M. Wulf, K. E. Tjardes, K. S. Mateo, T. E. Engle, C. L. Wright, and R. J. Maddock. 2004. The influence of feed-ing various levels of wet and dry grains on carcass quality, car-cass composition, and fatty acid profile of finishing steers. Proc. 57th Recip. Meat Conf. Accessed Jun. 13, 2011. http://www.meatscience.org.

Liu, Q., K. K. Scheller, S. C. Arp, D. M. Schaefer, and M. Frigg. 1996. Color coordinates for assessment of dietary vitamin E ef-fects on beef color stability. J. Anim. Sci. 74:106–116.

Roeber, D. L., R. K. Gill, and A. DiCostanzo. 2005. Meat quality responses to feeding distillers grains to finishing Holstein steers. J. Anim. Sci. 83:2455–2460.

Shackelford, S. D., M. Koohmaraie, M. F. Miller, J. D. Crouse, and J. O. Reagan. 1991. An evaluation of tenderness of the longis-simus muscle of Angus by Hereford versus Brahman crossbred heifers. J. Anim. Sci. 69:171–177.

USDA. 1996. Institutional Meat Purchasing Specifications for Fresh Beef. Agric. Mark. Serv., US Dept. Agric., Washington, DC.

Zerby, H. N., K. E. Belk, L. R. Sofos, L. R. McDowell, and G. C. Smith. 1999. Case life of seven retail products from beef cattle supplemented with α-tocopheryl acetate. J. Anim. Sci. 77:2458–2463.


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