Study on the antioxidant activity of quercetin extracts from Hypericum

Influence of ultraviolet light,reaction temperature on peroxide value of the sesame oil for adding quercetin extract from Hypericum,and relation of the free radical scavenging ratio of extracts were investigated.The results showed that the peroxide values of the sesame oil for adding quercetin extracts decreased 14.73%,25.53% and 38.4%,70.3% in comparison with adding BHT and no adding by ultraviolet light irradiation 6 h and reaction 10 h at 60 ℃,respectively.The free radical scaveng experiments showed that the reducing power at 60 ℃ is 1.88 times of BHT.The hydroxyl free radical scavenging ratio,the superoxide anion radical scavenging activities and the H2O2-scavenging capacity at 50 ℃ is 1.49,1.02 times and 1.04 times of BHT,respectively.