The influence of dietary lipid source and alpha tocopheryl acetate level on product quality of rainbow trout salmo gairdneri
Boggio, S.M.; Hardy, R.W.; Babbitt, J.K.; Brannon, E.L.
Aquaculture 51(1): 13-24
1985
ISSN/ISBN: 0044-8486
DOI: 10.1016/0044-8486(85)90236-4
Accession: 006696420
Rainbow trout (S. gairdneri) were fed practical diets containing either fish oil or swine fat and supplemented with 0, 50, 500, or 1500 mg of alpha-tocopheryl acetate per kg of diet for 4 months prior to harvest. The effects of diet on sensory attributes, fatty acid composition, tissue alpha-tocopherol level, and lipid oxidation during frozen storage were determined. Dietary fat source or alpha-tocopheryl acetate did not significantly affect sensory attributes of trout fillets evaluated fresh or after prolonged frozen storage. The fatty acid composition of the muscle and viscera were influenced by dietary fat source, most markedly in the levels of n-3 and n-6 fatty acids. Tissue alpha-tocopherol levels were significantly increased at dietary levels of 500 and 1500 mg alpha-tocopheryl acetate per kg diet. The dietary level of alpha-tocopheryl acetate required to prevent vitamin E deficiency signs was higher in fish fed the fish oil diet than in the fish fed the swine fat diet. Fish fed diets containing 500 and 1500 mg alpha-tocopheryl acetate had lower levels of malonaldehyde after frozen storage at -80.degree. C for 4 months, but not after frozen storage at -20.degree. C for 10 months.