VITAMIN-E SUPPLEMENTATION OF CATTLE AND SHELF-LIFE OF BEEF FOR THE JAPANESE MARKET

Feeder steers (n = 84) were stratified into four weight groups to prov ide slaughter groups so that product that had been in vacuum packages at 0 to 2 degrees C for 40, 60, 80, or 100 d postmortem could he simul taneously evaluated. Each of the four groups was randomly divided into three subgroups so that vitamin E could be supplemented in the diet a t rates of 0, 1,000, or 2,000 (EO, E1000, and E2000, respectively) IU. steer(-1).d(-1) for 100 d. After slaughtering, chilling, and fabricati ng, one ribeye-roll and one strip loin from each carcass was transport ed to the university laboratory for analyses, whereas the paired subpr imals were transported to Japan. Based on metmyoglobin formation and l ipid oxidation, strip loin steaks deteriorated at a faster rate during retail-display than did ribeye steaks. Steaks from subprimals that we re stored for 100 d had inferior (P < .05) retail-display characterist ics and a shorter (P < .05) caselife than steaks from the other storag e periods. alpha-Tocopherol levels in longissimus muscle were lower (P < .05) for EO than for E1000 and E2000 (3.51, 5.54, and 6.10 mu g/g o f tissue, respectively). Supplementing cattle with vitamin E resulted in steaks that exhibited superior lean color, less surface discolorati on, more desirable overall appearance, and less lipid oxidation during retail-display than control steaks; minimal differences were observed between E1000 and E2000 steaks. Steaks from cattle supplemented with vitamin E were preferred over control steaks by 91% of Japanese survey participants (n = 10,941), and 58% of all participants identified mus cle color as the most important factor in selecting beef products.