Inhibitory Effect of Bigeye Tuna Meat Extract on Sodium Chloride-Catalyzed Oxidation of Linoleate

Effect of the outer fraction of dialyzed water extract of bigeye tuna meat on NaCI-catalyzed oxidation of linoleate was examined using model system. Oxidation of linoleate was carried out at 25°C and Aw 0.84 and followed by determinations of remaining linoleate and POV. Linoleate oxidation was markedly inhibited by meat fraction which is diffusive through a cellophane membraae, adsorptive on cation exchange resin, and soluble in 80% EtOH. The inhibitory effect of the meat fraction on linoleate oxidation depended upon the concentration but not the pH. Furthermore, HCI-hydrolysis of the meat fraction resulted in loss of inhibitory effect on linoeate oxidation. From these results, amino acids and/or small molecular peptides such as anserine were considered to participate in the inhibitory effect of bigeye tuna meat extract on NaCl-catalyzed oxidation of linoleate.