Tissue equilibration and subcellular distribution of vitamin E relative to myoglobin and lipid oxidation in displayed beef.
Supplementary alpha-tocopheryl acetate (vitamin E) was fed to provide none (E0), 2,000 IU/d (E2000), 5.8 IU/kg live weight (E5.8), or 8.6 IU/kg live weight (E8.6) to steers that were individually fed mainly a corn diet. Three steers were placed on each of 10 treatments: E0, E2000, E5.8, E5.8 to d 126 then E0 to d 266, E0 to d 126 then E5.8 to d 266, E8.6, grazing followed by either E0 or E8.6 all with Holstein steers; and E0 and E2000 with crossbred beef steers. During the last 100 d, vitamin E consumption (International Units/day) averaged 96 for E0, 1,840 for E2000, 2,520 for E5.8, and 3,610 for E8.6. Concentrations of alpha-tocopherol in plasma and in liver and longissimus lumborum biopsy samples obtained every 42 d were elevated (P < .01) by vitamin E supplementation. Tissue saturation was approached at these vitamin E intakes causing similar incorporation of alpha-tocopherol with both per day and per BW supplementation strategies. Maximum accretion or depletion of alpha-tocopherol in plasma and liver occurred before 42 d, but accretion required 120 d and depletion required 180 d in longissimus lumborum. Vitamin E supplementation elevated (P < .01) concentrations of alpha-tocopherol in liver, lung, subcutaneous fat, omental fat, perirenal fat, kidney, diaphragm, spinal cord, longissimus lumborum, and plasma at slaughter with maximum accretion achieved (P < .01) in lung, subcutaneous fat, kidney, diaphragm, and spinal cord. Depletion was not achieved in longissimus lumborum and spinal cord (P < .01), subcutaneous fat (P < .06), and perirenal fat (P < .08) within 140 d. Vitamin E inhibited (P < .01) oxidation at the surface and center of longissimus lumborum steaks displayed for 19 d. Lipid oxidation occurred throughout E0 steaks, but metmyoglobin accumulation occurred more rapidly (P < .01) on the surface than in the center. Myoglobin and lipid oxidation were not concurrent events. Supplementation with vitamin E increased (P < .01) alpha-tocopherol concentrations in longissimus lumborum fractions (mitochondria, microsome, cytoplasm, connective, and remainder) but, except for connective tissue, the proportional distribution of total longissimus lumborum alpha-tocopherol was not affected (P > .1) by vitamin E supplementation. Vitamin E supplementation for at least 44 d at 1,300 IU/d is expected to incorporate adequate amounts of alpha-tocopherol into muscle (3.3 micrograms/g for longissimus lumborum) to produce beef with extended color and lipid stability.
Arnold
R N
RN
Department of Meat and Animal Science, University of Wisconsin, Madison 53706.
Arp
S C
SC
Scheller
K K
KK
Williams
S N
SN
Schaefer
D M
DM
D000273:Adipose Tissue / Q000378:metabolism; D000821:Animal Feed; D000818:Animals; D002417:Cattle / Q000378:metabolism*; D005527:Food, Fortified; D050356:Lipid Metabolism; D008099:Liver / Q000378:metabolism; D008297:Male; D008460:Meat / Q000592:standards; D008786:Metmyoglobin / Q000096:biosynthesis; D009132:Muscles / Q000378:metabolism; D009211:Myoglobin / Q000378:metabolism*; D010084:Oxidation-Reduction; D010858:Pigmentation; D012044:Regression Analysis; D014018:Tissue Distribution; D014810:Vitamin E / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics*
D009211:Myoglobin; D008786:Metmyoglobin; D014810:Vitamin E