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

Abstract

Addition of 200 ppm all-rac-α-tocopheryl acetate to pig feed supplemented with 6% high-oleic rapeseed oil gave mitochondrial membranes, which had a lower rate of formation of free radicals as determined by ESR-spectroscopy using the spin-trapping technique. Addition of 175 mg/kg copper to the feed, with or without all-rac-α-tocopherol acetate addition was not pro-oxidative (or anti-oxidative). While these effects were similar for both the oxidative M. Psoas major (PM), and the glycolytic, M. Longissimus dorsi (LD), differences between muscles were characterised by a higher activity of β-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 α-tocopherol in muscles, liver, and plasma was influenced by the α-tocopherol level in the feed ( p<0.001). The concentration of fatty acids in microsomes was not influenced by dietary treatments, but was higher in PM than in LD. However, the total concentration of fatty acids in the mitochondria of PM was higher in pigs supplemented with all-rac-α-tocopheryl acetate.