Distribution of α‐and γ‐tocopherols in Atlantic salmon (Salmo salar) tissues

Abstract

Groups of Atlantic salmon parr (mean initial weight 9.5 g) were fed three diets, the first containing no tocopherol supplement, the others supplemented with either all-rac-alpha-tocopherol (A-T) or RRR-gamma-tocopherol (G-T). Tocopherol concentrations in the liver, serum, testes, kidney, brain, gill, muscle, and perivisceral fat were measured after 36 wk. Despite a higher dietary intake of G-T, compared to A-T, deposition of gamma-tocopherol (gammaT) was less efficient than of alpha-tocopherol (alphaT) in most tissues except in the perivisceral fat, an adipose tissue. In fish fed the G-T diet, the gammaT/alphaT ratio was highest in the perivisceral fat and lowest in the liver, indicating that the liver is the most discriminatory organ for retaining alphaT as compared to gammaT, and the perivisceral fat is more suitable for the storage of gammaT. A negative correlation (P < 0.01) was observed between the gammaT/alphaT ratio and the corresponding tissue phospholipid content, suggesting that gammaT is less efficiently deposited compared to alphaT in the phospholipid-rich membranes which are presumed to be the functional site for lipid antioxidants in vivo. During restricted intake of alphaT, the liver and muscle exhibited the greatest reduction of this tocopherol among the tissues analyzed. The presence of minimal alphaT in the muscle from fish fed the tocopherol-unsupplemented diet led to greater susceptibility to lipid peroxidation after frozen storage than was the case for muscle containing higher concentrations of either alphaT or gammaT. However, both alphaT and gammaT were effective stabilizers of salmon muscle lipids during frozen storage.

Natural antioxidants in the stability of ray liver oil

“…Result agrees with PARAZO et al (1998), who reported a high selectivity of α-isomers in fish liver oil. NAVARRO-GARCIA et al (2004) reported α-tocopherol contents in different ray species from 1.6 to 64.9mg 100g -1 .…”

Oxidative resistance, carotenes, tocopherols and lipid profile of liver oil of the ray Rhinoptera steindechneri

“…The a-tocopherol was the only form of tocopherols present in the oil. According to Parazo et al (1998), this tocopherol isomer is the only form stored in the fish liver. The concentration of a-tocopherol detected varied widely among the specimens between 3.0 and 15.2 mg/g of oil (Table 2).…”

Untitled

“…One of the most effect ive antio xidants is α-tocopherol as it breaks the free radical chain reaction by forming a relatively stable tocopheroxy l radical (Selley et al, 1991). α-tocopherol is identified as the major naturally occurring tocopherol in the lipids of marine organisms (Ackman and Cormier, 1978;Parazo et al, 1998). It is essential for integrity and optimal function of reproductive, muscular, circulatory, nervous and immune systems (Hoekstra, 1975;Sheffy and Schult z, 1979;McDo well, 2000).…”