EFFECT OF DIETARY ALPHA-TOCOPHEROL SUPPLEMENTATION ON THE MOLAR RATIO OF POLYUNSATURATED FATTY-ACIDS ALPHA-TOCOPHEROL IN BROILER SKELETAL-MUSCLES AND SUBCELLULAR MEMBRANES AND ITS RELATIONSHIP TO OXIDATIVE STABILITY

Five groups of broilers (all males) with 6 birds in each were fed diets supplemented with dl-alpha-tocopheryl acetate (ATA) at a level of 0, 100, 250, 500 or 1 000 mg per kg of feed, respectively, for the last two weeks prior to slaughter. Dietary supplementation with ATA increased the alpha-tocopherol (alpha-Toc) contents of the skeletal muscle, subcellular membranes, liver and adipose tissue in proportion to the supplementary levels, decreased the molar ratios of PUFA or PUFA > 18:2 (PUFA with three or more double bonds) to alpha-Toc in the muscle and subcellular membranes, and improved the oxidative stability of the white (M. pectoralis superficialis) and dark (thigh muscles) meat during refrigerated storage. Broiler dark and white meat with about 200 or less molar ratios of PUFA > 18:2 to alpha-Toc gave TBA values of less than about 0.1 and were highly stable to lipid oxidation in the raw ground state over 5 days of storage at 0-degrees-C. For cooked ground samples, however, it failed to protect the cooked meat lipids from becoming oxidized, even though broilers were fed diets supplemented with up to 1 000 mg ATA/kg of feed.