Radical-scavenging activity: Role of antioxidative vitamins in some fish species

To evaluate fish as free radical scavengers in the human diet, we examined the radical-scavenging activity of some marine fish tissue commonly consumed in Japan, using the 1,1-diphenyl-2-picrylhydrazyl (DPPH)-HPLC and 2'-deoxyguanosine oxidation method. All fishes showed high HPPH (259-2225 mu mol Trolox eq./100g) and oxygen (1059-8018 mu mol Trolox eq./100g) radical-scavenging activity. Ascorbic acid and tocopherol content were determined as free radical-scavenging compounds and ranged from 0.6-7.8 and 0.5-16.6 mg/100 g fresh weight, respectively. Fish liver and skin showed higher contents of these antioxidative compounds than other parts, although their contribution to DPPH radical scavenging activity was negligible. Unlike vegetables some other compounds seem to be responsible for the high scavenging activity of fish.