响应面法优化微波辅助提取成熟叶老鹰茶总黄酮及其抗氧化研究

Optimization of Microwave-assisted Extraction of Total Flavonoids from Matured Leaf Hawk Tea by Response Surface Methodology and Its Antioxidant Activity

以成熟叶老鹰茶为原料,在单因素试验的基础上,以总黄酮得率为指标,采用响应面法优化微波辅助提取其总黄酮的最佳工艺条件,并通过老鹰茶总黄酮对1,1-二苯基苦基苯肼自由基(DPPH·)的清除和铁离子还原能力(FRAP)来评价其抗氧化能力。结果表明,经过优化后的工艺参数为:成熟叶老鹰茶1 g微波时间61 s,微波功率560 W,液料比10∶1(mL∶g),乙醇体积分数80.3%,此条件下总黄酮得率为6.52%。成熟叶老鹰茶总黄酮具有较强的DPPH·清除和铁离子还原能力,质量浓度20 g/L时,DPPH·清除率66.66%,铁离子还原能力相当于2.05 mmol/L FeSO4,并呈一定的量效关系。

The optimal microwave-assisted extraction conditions of total flavonoids from matured leaf Hawk tea were studied. In order to increase the extraction yield of total flavonoids, the microwave-assisted extraction conditions of total flavonoids from matured leaf Hawk tea were optimized by response surface methodology based on the single-factor tests. Meanwhile, the antioxidant activity of total flavonoids from matured leaf Hawk tea was evaluated by the DPPH radical scavenging capacity and ferric reducing activity power. The optimal parameters of total flavonoids were matured leaf Hawk tea 1 g, microwave time 61 s, microwave power 560 W, ratio of water to solid 10：1 （mL：g）, ethanol concentration 80. 3 %. The maximum extraction yield of total flavonoids was 6. 52 %. At 20 g/L, DPPH radical scavenging activity and FRAP value of extracted total flavonoids were 66. 66 % and 2. 05 mmol/L FeSO4 , respectively. They all showed a dose-dependent manner.