Department of Marine Bioscience, Fukui Prefectural University, Obama, Fukui 917-0003
The progress of lipid oxidation during processing of two different types of Japanese traditional seafood, heshiko and narezushi, produced by aging of salted mackerel with rice bran or cooked rice for several months, was investigated by monitoring the changes in peroxide value (PV), carbonyl value (CV), and thiobarbituric acid reactive substance (TBA-RS) as oxidation indices. Storage of mackerel with 20% NaCl for 4 months at ambient temperature markedly increased PV, CV, and TBA-RS, indicating that lipid oxidation was promoted by long-term storage of salted mackerel. In contrast, little increase was observed in PV, CV, and TBA-RS during aging of salted mackerel with rice bran at ambient temperature for 6 months, demonstrating that lipid oxidation during processing of heshiko barely proceeded. On the other hand, lipid oxidation in salted mackerel during aging with cooked rice in narezushi processing proceeded similarly to that in salted mackerel with 5% NaCl. The progress of lipid oxidation in processing of heshiko and narezushi was associated with changes in 1,1-diphenyl-2-picrylhydrazyl (DPPH) scavenging activity and antioxidative capacity on a linoleic acid autoxidation model system in meats, rice bran or cooked rice during the processing of these aged and fermented products.