Study on Extraction of Flavonoids from Tamarind Leaves and Scavenging Effect on Hydroxyl Radicals

[Objective]The aim was to study extraction of flavonoids and scavenging effect on hydroxyl radicals [Method]Flavonoids were extracted from tamarind leaves by using ethanol reflux method from tamarind leaves. and the preferred extraction conditions were determined by single factor experiment. [Result]The study showed that the best extraction conditions was ethanol concentration of 70%,solid-liquid ratio of 1∶ 30( mg/ml),reflux temperature of 85 ℃ and extraction time of 2.5 h. The extraction ratio of flavonoids was 1.83% by using spectrophotometry.Antioxidant effects of flavonoids,rutin and BHT were measured to remove hydroxyl radicals by comparative experiments. Antioxidant activity was ordered as flavonoids rutin BHT. [Conclusion]Antioxidant experiments showed that flavonoids from tamarind leave had a strong scavenging effect on hydroxyl radicals.