Deposition of tocotrienols and tocopherols in the tissues of red hybrid tilapia, Oreochromis sp., fed a tocotrienol-rich fraction extracted from crude palm oil and its effect on lipid peroxidation

A 9-week feeding trial was conducted to evaluate the effects of dietary vitamin E on fish growth, lipid peroxidation and distribution of tocopherols and tocotrienols in various tissues of red hybrid tilapia. Five semi-purified isoenergetic and isonitrogenous diets were supplemented with 0, 30, 60, 120, or 240 mg of total vitamin E derived from a tocotrienol-rich fraction (TRF) extracted from crude palm oil/kg diet. At the end of the feeding trial, there were no significant differences (P > 0.05) in percent weight gain, feed conversion ratio or protein efficiency ratio among fish fed the various diets. Muscle, liver, adipose tissue, skin and plasma concentrations of alpha-tocopherol, alpha-tocotrienol, and gamma-tocotrienol increased linearly in response to increasing dietary concentrations originating from the added TRF. alpha-Tocopherol constituted 51.2-94.2% of the total vitamin E deposited in various tissues. The deposition of tocotrienols was highest in the perivisceral adipose tissue of tilapia fed the TRF supplemented diets (average 47.7% of total vitamin E), followed by liver (29.3%), skin (23.6%), muscle (25.9%) and plasma (9.0%). The concentrations of thiobarbitufic acid-reactive substances from Fe2+-catalysed vitamin C induced lipid peroxidation in muscle, liver and plasma of tilapia fed diets with no added vitamin E were significantly higher (P < 0.05) than that found in the tissues of fish fed diets supplemented with TRF from palm oil. Results obtained indicated that TRF supplementation could markedly enhance the tocotrienol and tocopherol concentration in various tilapia tissues and provide higher protection of these tissues against lipid peroxidation. (C) 2005 Elsevier B.V. All rights reserved.