Influence of the Dietary Polyunsaturation Level on Chicken Meat Quality: Lipid Oxidation

The present study was carried out to evaluate the influence of increasing amounts of dietary polyunsaturated fatty acids (PUFA) and α-tocopheryl acetate (α-TA) supplementation on lipid oxidation of raw and cooked thigh meat stored under refrigeration. One hundred ninety-two female, 1-d-old, broiler chickens were randomly distributed into 16 experimental treatments resulting from the combination of 4 levels of dietary PUFA (15, 34, 45, and 61 g/kg) and 4 levels of supplementation with α-TA (0, 100, 200, and 400 mg/kg). Thiobarbituric acid reactive substance (TBARS) values in cooked meat and cooked refrigerated meat were 12- and 24-fold higher, respectively, than in raw meat. Dietary polyunsaturation and α-TA supplementation affected lipid oxidation more markedly in cooked meat and cooked refrigerated meat than in raw meat and raw refrigerated meat. Lipid oxidationa in cooked meat showed a significant linear increase as the concentration of PUFA in raw meat increased. The oxidative stability of meat was not affected by an increase in the dietary α-TA level from 200 to 400 mg/kg. Nonlinear relationship between TBARS values in cooked meat and α-tocopherol content of raw meat showed saturation in the antioxidant effect of α-Toc. The equation y = x (11.88+ 63.38e−0.007z) was calculated to predict the minimum inclusion of α-tocopherol to diets (z) of chickens with certain dietary PUFA content (x) to assure a certain TBARS value (y).