The in vitro investigation of alpha lipoic acid supplementatıon on protein quality of sea bream (Sparus aurata), anchovy (Engrailus engrasichalus) and atlantic bonito (Sarda sarda)

In this study, the effect of alpha lipoic acid as an antioxsidant on protein quality of sea bream, anchovy and Atlantic bonita oxidized with Fe+2 catalyzed oxidation system were investigated. Protein carbonyl (nmol carbonyl/ mg protein) and sodium dodecyl sulfade polyacrylamide gel elctrophoresis (SDS-PAGE) were used to determine protein oxidation and denaturation, respectively. As a result of this study, a significantly decrease in the amount of protein carbonyl was obtained with 1% alpha lipoic acid supplementation for seabream and 0.5% alpha lipoic acid supplementation for Atlantic bonita. In anchovy, the amount of protein carbonyl decreased with 0.1% and 0.5% alpha lipoic acid supplementation. However, 1% alpha lipoic acid supplementation did not effect on the amount of protein carbonyl. Results from electrophoresis anaylses indicated that the alpha lipoic acid did not show a good antioxidant property for these species and also it showed prooxidant activity in the dark muscle of fish when it was used of the ratio of 1%.