超声波辅助提取茶叶总黄酮及抗氧化活性分析

Study on ultrasonic-assisted extraction and antioxidant activity of flavonoids from tea

采用超声波辅助法探讨了铁观音茶叶中总黄酮的最佳提取工艺条件,并测定了铁观音茶叶总黄酮清除羟基自由基的能力.结果表明,超声波功率400 W,料液比1∶30 g·mL^(-1),浸提时间30 min,乙醇浓度50%为超声波辅助提取铁观音茶叶总黄酮的最佳工艺条件,总黄酮提取率为4.74%;抗氧化实验表明随着铁观音茶叶总黄酮浓度的增大,其对羟基自由基的清除能力增大,当浓度达到0.80 g/L,清除率为65.14%,与BHT相比具有较强的抗氧化能力.

Flavonoids from Tieguanyin tea were extracted by ultrasonic method, and their antioxidant activity was determined. The results showed that the optimum extraction conditions are ultrasonic power of 400 W, material to liquid ratio of 1 ： 30 g ·mL-1 , extracting time of 30 min, ethanol concentration of 50%, and the extraction yield of tea flavonoids is 4.74%. With the increasing concentration of tea flavonoids, their antioxidant activity became greater. When the concentration of tea flavonoids reaches 0.80 g/L, clearance rate of free radical is 65.14%. The antioxidant capacity of tea flavonoids is stron- ger than butylated hydroxytoluene （BHT）.