FREE-RADICAL SCAVENGING ACTIVITIES OF FLOWER PETAL EXTRACTS

The scavenging activity of extracts from edible flower petals and gree n tea was investigated by ESR (electron spin resonance). Thirteen kind s of petal extracts scavenged DPPH (1,1-diphenyl-2-picrylhydrazyl) rad ical. The correlation coefficient of DPPH radical scavenging activity with the antioxidant activity was 0.787. The antioxidative activities of the petal extracts were examined by the method to measure the rate of discolaration of beta-carotene coupled with the oxidation of linole ic acid. The petal extracts also scavenged the hydroxyl radical and su peroxide. These activities correlated closely with the concentration o f polyphenols measured by Folin-Denis method. The correlation coeffici ents of scavenging activity toward DPPH radical, hydroxyl radical and superoxide with the polyphenol content were 0.837, 0.707 and 0.904, re spectively. Rose tea and green tea strongly scavenged DPPH radical. Th e tea extract had strong scavenged activity of DPPH radical. These res ults exhibited that the free radical scavenging activity primarily dep ends on the polyphenol content.