响应曲面优化余甘子多酚的亚临界水萃取工艺及其抗氧化性研究

Optimization of subcritical water extraction technology of emblica polyphenols by response surface methodology and antioxidant activity

以余甘子干果粉为原料,研究亚临界水萃取余甘子多酚的工艺条件及其抗氧化活性。通过单因素试验探讨了亚临界水萃取余甘子多酚工艺中萃取温度、萃取时间、萃取压力和液料比等因素对多酚提取率的影响,利用响应曲面分析法优化提取工艺。最佳优化工艺参数:余甘子干果粉碎过40目筛,纯水80m L,液料比47∶1,亚临界萃取温度212℃,提取11min,余甘子多酚平均提取率17.08%,实测值与预测值符合良好。高效液相分析表明,亚临界水萃取样品中没食子酸提取率达3.284%,远高于溶剂回流提取。体外抗氧化活性研究表明,亚临界水萃取余甘子多酚具有一定清除DPPH自由基和羟基自由基的能力,其IC50值分别为7.05μg/m L和54.35μg/m L,小于TBHQ和溶剂回流提取样品。体现了亚临界水萃取具有较好的选择性、快速、高效、环境友好等优点。

Subcritical water extraction technology of emblica polyphenols was studied. Effects of subcritical water extraction temperature, extraction time, pressure and ratio of liquid to material on extraction yield of emblica polyphenols were investigated through single factor test. Three key factors affecting the extraction yield were optimized by response surface methodology. The optimum extraction conditions for emblica polyphenols were identified as the follows., emblic leafflower fruit crushed, the particle size as 40 screen mesh, pure water 80mL as solvent, ratio of liquid to material as 47 ： 1 （V/W）, extraction temperature as 212℃, extraction time 1 lmin, the extraction yield of emblica polyphenols was up to 17.08%, which was consistent with the predicted value. The extraction yield of gallic acid was up to 3.284%, which was observably higher than the yield by solvent extraction. Antioxidant assays revealed that emblica polyphenols extracted by subcritical water had a better DPPH and hydroxyl free radical scavenging activities than those of the antioxidant TBHQ and solvent reflux extraction sample, and the half inhibitory concentrations （IC50） were 7.05 and 54.35μg/mL respectively. All these results indicate that subcritical water extraction is a rapid, efficient and environmentally friendly method with good selectivity.