EFFECTS OF SUPRANUTRITIONAL DIETARY VITAMIN-E LEVELS ON SUBCELLULAR DEPOSITION OF ALPHA-TOCOPHEROL IN THE MUSCLE AND ON PORK QUALITY

The influence of three levels of vitamin E in the diet of pigs on the subcellular deposition of alpha-tocopherol in the muscle and on selected quality characteristics of pork meat (oxidative stability of lipids, colour, drip loss, microbial growth) was studied. The content of alpha-tocopherol in adipose tissue and L. dorsi muscle as well as in mitochondrial and microsomal fractions of the muscle significantly increased (P < 0.05) with increasing levels of dietary vitamin E. The differences in the concentrations of alpha-tocopherol in the subcellular fractions were evident in the enhanced stability of the membranes when exposed to metmyoglobin/hydrogen peroxide. The beneficial effect of dietary vitamin E on the oxidative stability of pork lipids during the storage of pork chops and ground pork was also demonstrated. Even though lipid oxidation increased in all cases during storage, the pork products from the pigs receiving the highest level of vitamin E (200 IU kg-1 feed) exhibited the smallest increase in thiobarbituric acid reactive substances. In addition, increased colour stability and decreased drip loss were observed on keeping pork chops, which had been previously frozen for three months, at 4-degrees-C under fluorescent light for 10 days. The possible effect of alpha-tocopherol on membrane fluidity in this context is discussed.