Abstract

This study evaluated the effect of dietary supplementation of vitamin E on glutathione content, and lipid and protein oxidative stability during refrigerated storage of broiler meat. Ninety one-d-old chicks were randomly assigned to one of two groups. The control group had a basal diet and the vitamin E (Vit E) group received 200 mg/kg alpha-tocopheryl-acetate as a supplement for 42 d. Lipid oxidation was assessed by the thiobarbituric acid reactive substances (TBARS) method, protein oxidation was estimated by carbonyl content and glutathione was measured by thiol content. Oxidised protein content in breast tissue remained stable during 6 days of refrigerated storage at 4 degrees C. In thigh tissue, the oxidised protein content significantly increased at 4 d of storage and then decreased. The TBARS content of meat of chickens supplemented with Vit E was lower than that from control during all time points of refrigerated storage. Meat from Vit E treated chickens had lower TBARS content than control meat when estimated at temperature-induced lipid oxidation conditions. In control meat, the TBARS content increased until 4 days of cold storage and then decreased at 6 days. The glutathione content of refrigerated breast tissue in all treatments remained constant during the first 4 d of refrigerated storage but exhibited a decrease thereafter. This research confirms that Vit E supplements in chicken feed protect their meat from lipid oxidation.