Influence of supranutritional vitamin E and copper on alpha-tocopherol deposition and susceptibility to lipid oxidation of porcine membranal fractions of M-Psoas major and M-Longissimus dorsi

Addition of 200 ppm all-rac-alpha-tocopheryl acetate to pig feed supplement ed with 6% high-oleic rapeseed oil gave mitochondrial membranes, which had a lower rate of formation of free radicals as determined by ESR-spectroscop y using the spin-trapping technique. Addition of 175 mg/kg copper to the fe ed, with or without all-rac-alpha-tocopherol acetate addition was not pro-o xidative (or anti-oxidative). While these effects were similar for both the oxidative M. Psoas major (PM), and the glycolytic, M. Longissimus dorsi (L D), differences between muscles were characterised by a higher activity of beta-hydroxyacyl-coenzyme A-dehydrogenase (HAD) and citrate synthase (CS), and a lower activity of lactate dehydrogenase (LDH) in PM than in LD (p < 0 .001). The concentration of a-tocopherol in muscles, liver, and plasma was influenced by the alpha-tocopherol level in the feed (p < 0.001). The conce ntration of fatty acids in microsomes was not influenced by dietary treatme nts, but was higher in PM than in LD. However, the total concentration of f atty acids in the mitochondria of PM was higher in pigs supplemented with a ll-rac-alpha-tocopheryl acetate. (C) 2000 Elsevier Science Ltd. All rights reserved.