银杏叶多酚的机械力辅助提取及其体外抗氧化活性研究

为优化银杏叶多酚提取工艺,通过单因素试验考察填充率、球磨转速、球磨时间、乙醇浓度、料液比、提取温度、提取时间七个因素对机械力辅助提取银杏叶多酚得率的影响,以银杏叶多酚得率为响应值,采用Box-Benhnken三因素三水平响应面设计优化工艺,同时比较了4种提取方法对银杏叶多酚提取得率和抗氧化活性的差异。结果表明,机械力辅助提取银杏叶多酚的最佳工艺条件为:填充率26%、球磨转速为400rpm、球磨时间为15min。在此条件下,银杏叶多酚的得率为7.33%。机械力辅助乙醇提取银杏叶多酚得率低于碱水提取法,但是抗氧化活性高于碱水法提取的银杏叶多酚;抗氧化活性与乙醇回流法提取的银杏叶多酚相当,但是提取得率高于乙醇回流法。此提取工艺高效可行,具有一定的参考价值。

Mechanically assisted extraction and antioxidant activity in vitro of polyphenols from Ginkgo biloba leaves

To optimize the extraction process,polyphenols from Ginkgo biloba leaves was extracted with the mechanically assisted extraction method.Through single factor experiment,the effect of filling rate,ball milling speed,ball milling time,ethanol concentration,solid-liquid ratio,extraction temperature and extraction time on the yield of polyphenols from Ginkgo biloba leaves was examined.Box-Benhnken three factors three levels experiment by response surface design was carried out.Besides,the differences of extraction rate and antioxidant activity of polyphenols from Ginkgo biloba leaves by four extraction methods were compared.Results showed that the optimum extraction conditions of mechanically assisted extraction of polyphenols from Ginkgo biloba leaves were filling rate 26%,ball milling speed 400 rpm and ball milling time 15 min.Under these conditions,the yield of polyphenols from Ginkgo biloba leaves was 7.33%.The extraction yield of polyphenols from Ginkgo biloba leaves by mechanically assisted ethanol extraction method was lower than that extracted by alkaline water extraction method,but the antioxidant activity was higher than that extracted by alkaline water extraction method.The antioxidant activity of polyphenols of Ginkgo biloba leaves by mechanically assisted ethanol extraction method was similar to that extracted by ethanol reflux extraction method,but the extraction rate was higher than that by ethanol reflux extraction method.The extraction process was efficient,feasible and worth using for reference.