Effect of soy sauce on the antioxidative capacity of the gelatin gel food 'Nikogori' measured using the chemiluminescence method.

Oxygen-related free radicals have been suggested as a cause of aging and various diseases, for example, various cancers and rheumatoid arthritis. Because of this a radical scavenger as an antioxidant has been sought in many foods. 'Nikogori' gelatin gel from cooked fish is a traditional food in Japan. Recently, 'Nikogori' has been noted as a readily consumed food for the elderly and those with medical problems associated with swallowing. In this study we report that the 'Nikogori' gelatin gels made from the collagen in various meats have a high peroxyl radical scavenging capability as the antioxidative capacity using the chemiluminescence method and the order of the strength of antioxidative capacity (IC(50) value) was the Japanese common squid mantle meat (0.163%) > flatfish (marbled sole) meat (0.534%) > chicken wing meat (0.585%) > beef shin meat (0.655%) > yellowtail meat (0.659%) > chub mackerel meat (0.789%). Furthermore, when soy sauce was added to the 'Nikogori' gelatin gel, the antioxidative capacity increased markedly to 0.098% of IC(50) value of yellowtail, 0.165% of chicken, 0.182% of flatfish and 0.252% of chub mackerel.