Effect of dietary oils and alpha-tocopheryl acetate supplementation on lipid (TBARS) and cholesterol oxidation in cooked pork.

The effect of n−3 fatty acid-enriched diets (in the form of 0.5% linseed oil with either 1.5% sunflower oil or 1.5% olive oil) and α-tocopheryl acetate supplementation (200 mg/kg feed) on lipid oxidation (thiobarbituric acid-reactive substances, TBARS) and cholesterol oxide products (COPS) in cooked pork was investigated. Longissimus muscle was studied. Meat from pigs fed 0.5% linseed oil-enriched diets had a higher proportion of n−3 fatty acid than meat from pigs in other dietary groups in neutral (P < 0.0001) and polar lipids (P < 0.0001), and a 20% reduction in the n-6:n- 3 ratio was observed. α-Tocopheryl acetate supplemen- tation increased (P < 0.05) monounsaturated fatty acids in polar lipids and increased (P = 0.0001) α-tocopherol levels in muscle. α-Tocopherol concentration in muscle was affected by dietary fat (P < 0.05). Groups receiving diets enriched with sunflower oil had significantly higher α-tocopherol levels (P < 0.05) in muscle than those groups receiving olive oil-enriched diets. Num- bers of TBARS were significantly (P < 0.05) lower in the group fed supplemental olive oil than in those fed sunflower oil. Dietary linseed oil increased (P < 0.05) lipid oxidation principally at the initial period of storage in cooked pork. Overall, dietary α-tocopheryl acetate supplementation significantly increased (P < 0.001) lipid stability and decreased (P < 0.05) total COP pro- duction across the dietary groups. α-Tocopherol was a more effective antioxidant for decreasing TBARS val- ues in cooked meat when adding sunflower oil to the diets instead of olive oil.