The relationship between muscle α-tocopherol concentration and meat oxidation in light lambs fed vitamin E supplements prior to slaughter.

ABSTRACT

BACKGROUND: The use of concentrates supplemented with α-tocopherol in animals is an effective method to reduce the oxidative processes that occur in meat products. The high cost of α-tocopherol requires accurate feeding, so it is necessary to define the minimum period of α-tocopherol concentrate supplementation that will ensure an acceptable meat quality. Indoor concentrate-fed light lambs (n = 35) were supplemented with 500 mg dl-α-tocopheryl acetate (VE) kg(-1) concentrate for a period of between 4 and 28 days before being slaughtered at 22-24 kg body weight. Control lambs (n = 12) were not supplemented with α-tocopherol. RESULTS: The α-tocopherol content in both plasma and muscle tissues increased significantly with the length of supplementation (P < 0.001). The thiobarbituric acid-reactive substance (TBARS) concentration in meat decreased exponentially when the muscle α-tocopherol concentration was increased to 0.61-0.90 mg kg(-1) fresh meat (P < 0.05). After 7 days of display, the formation of metmyoglobin (MMb) decreased significantly as the α-tocopherol content increased to 0.31-0.60 mg kg(-1) meat (P < 0.05). CONCLUSION: A range of 0.61-0.90 mg α-tocopherol kg(-1) fresh meat protected fresh lamb meat from lipid oxidation and MMb formation. This level can be achieved by supplementation with 500 mg VE kg(-1) concentrate for a period of 7-14 days before slaughter.