响应面优化微波辅助提取石橄榄总黄酮及其抗氧化研究

Optimization of microwave-assisted extraction of total flavonoids from Pholidota chinensis Lindl. by response surface methodology and its antioxidant activity

以石橄榄为原料,在单因素试验基础上,以总黄酮提取率为响应值,采用Box-Behnken实验设计方法,研究各自变量及其交互作用对总黄酮提取率的影响,并利用Design-Expert软件,建立了总黄酮提取率与提取过程中各因素的二次多项式模型。结果表明,微波辅助提取石橄榄总黄酮的最佳工艺条件为:液料比21 m L·g-1、乙醇浓度60%、微波功率800 W,微波时间63 s,该条件下总黄酮提取率为1.52%,与预测值相对误差为0.65%,验证了该模型的有效性。以维生素C为对照,考察了石橄榄总黄酮对·OH和DPPH·的清除能力。结果显示,石橄榄总黄酮具有较强的清除·OH和DPPH·的能力,并均呈一定的量效关系,说明石橄榄总黄酮可作为一种天然的抗氧剂。

Response surface methodology was used to optimize the processing conditions for extraction of total flavonoids from Pholidota chinensis Lindl. using microwave-assisted extraction method. Based on the sin- gle-factor experiments, Box-Benhnken design was used to set up a quadratic polynomial regression equation for the yield of total flavonoids. The effects of individual variables and their interactions on the yield were studied using response surface analysis. The results showed that the optimal extraction conditions were： the ratio of liquid to material, 21 mL·g^-1; ethanol concentration, 60 %; microwave powder, 800 W; and microwave time, 63 s. The yield of total flavonoids could be up to 1.52 % under the optimal extraction condition and the relative error was 0.65 % compared to the predictive value, which indicated the feasible model fitted well with the experimental data. Meanwhile, the .OH and DPPH＂ scavenging capacity of total flavonoids were studied by taking vitamin C as a referential substance. The result showed that total flavonoids from Pholidota chinensis had good free radicals scavenging activity on -OH and DPPH＂ with a dose-effect relationship, respectively. The total flavonoids from Pholidota chinensis could be used as natural antioxidants.