板栗叶总黄酮提取工艺的优化及其抗氧化活性

采用响应面法优化板栗叶总黄酮的加压溶剂提取工艺,并考察其抗氧化活性。通过单因素试验考察循环次数、提取温度、提取时间、乙醇体积分数4个因素对板栗叶总黄酮提取率的影响,并采用Box-Behnken设计对提取工艺进行优化,通过DPPH自由基和ABTS+自由基清除以及总抗氧化能力研究其抗氧化活性。结果表明,循环次数为2次,提取温度为73℃,提取时间为7.3 min,乙醇体积分数为40%时总黄酮提取率达到最大值,为(5.18±0.06)%,与预测值(5.20±0.10)%稳合良好。在所设最大板栗叶黄酮提取液浓度下,DPPH自由基清除率为88.44%,ABTS+自由基清除率为82.76%,总抗氧化能力为980.3μmol/L,表明具有很好的抗氧化活性。

Optimization of Extraction Process of Total Flavonoids from Chestnut Leaves and Its Antioxidant Activity

The accelerated solvent extraction process of total flavonoids from chestnut leaves was optimized by response surface methodology,and the antioxidant activity was investigated.The effects of cycle times,extraction temperature,extraction time and ethanol volume fraction on the extraction rate of total flavonoids from chestnut leaves were investigated by factor experiments.Box-Behnken design was performed to optimize the extraction conditions.The antioxidative capacities of chestnut leaves extracts cultured were evaluated using DPPH,ABTS+and FRAP assays.The results showed that the optimum extraction conditions were 2 cycles for 7.3 min(extrac tion time)at 73℃(extraction temperature)with 40%ethanol(volume fraction).Under these optimal conditions,the extraction rate of flavonoids reached the maximum of(5.18±0.06)%,which was well stabilized with the predicted value of(5.20±0.10)%.At the maximum chestnut leaves flavonoid extract concentration,the DPPH free radical scavenging rate was 88.44%,the ABTS+free radical scavenging rate was 82.76%,the total antioxidant capacity of chestnut leaves flavonoids were 980.3μmol/L,and which indicated that the antioxidant activity of chestnut leaves flavonoid was strong.