Storage Stability of Channel Catfish (Ictalurus punctatus) in Relation to Dietary Level of α-Tocopherol

Abstract

Fingerling channel catfish (I. punctatus) 12-15 cm long were fed semipurified diets containing 0, 5, 10, 20, 40 and 80 mg of dl-.alpha.-tocopherol acetate/100 g dry diet and slaughtered after 97 days. Storage stability of fillets for the different treatments was determined by 2-thiobarbituric acid analysis after 3 mo. frozen storage and after 3 mo. freezing followed by refrigeration for 3 days. Fillets from fish fed the 2 lowest .alpha.-tocopherol levels exhibited significant oxidative rancidity after frozen storage. All higher levels showed similar but negligible oxidation. The 3 days of additional refrigerated storage significant increased the amount of fat oxidation in all fillets from fish fed less than 40 mg/100 g. Increased dietary levels of .alpha.-tocopherol are apparently effective in increasing the storage stability of catfish fillets.