Dietary versus postmortem supplementation of vitamin E on pigment and lipid stability in ground beef.

Effects of dietary supplementation and postmortem addition of vitamin E on pigment and lipid stability in raw ground beef were examined in this study. Six Holstein steers were fed a control diet for 232 or 252 d and six Holstein steers were supplemented with 1,500 IU of vitamin E per animal daily for 232 or 252 d. Three aliquots of ground beef from each longissimus lumborum were allotted to the following postmortem treatments: no addition (NO), white mineral oil (OIL), and white mineral oil containing sufficient D-alpha-tocopherol to equal the mean difference of alpha-tocopherol concentration between beef from supplemented and control steers (OIL + E). Metmyoglobin percentages and 2-thiobarbituric acid reactive substances values were determined at d 1, 3, 5, 7, and 9 after postmortem treatment. Dietary vitamin E supplementation delayed metmyoglobin increase and highly suppressed lipid oxidation in ground beef during 9 d of display compared with the control. The postmortem addition of vitamin E (OIL + E) was slightly effective in retarding the oxidation of pigment and lipid, especially compared with the OIL treatments. Endogenous vitamin E improved pigment and lipid stability much better than exogenous vitamin E.