机械化学辅助双水相提取绿茶渣中的茶多酚

Mechanochemical⁃assisted double aqueous⁃phase system extraction of tea polyphenols from green tea residue

开发了一种高效且具备选择性提取能力的机械化学辅助双水相提取技术用于提取绿茶渣中的茶多酚。通过单因素以及响应面优化实验优化了实验条件,结果表明,最优工艺条件为硫酸铵质量分数18%、乙醇质量分数35%、液固比65 mL/g、转速468 r/min、提取时间10 min,在此条件下茶多酚的最大产率为50.01±0.26 mg/g,接近传统机械化学法(52.36±0.34 mg/g);同时机械化学辅助双水相提取法所得产物的含固率为46.2%,远高于传统机械化学法(21.6%);此外,机械化学辅助双水相提取法提取的茶多酚体外抗氧化活性能力明显高于传统方法。

Tea residue,as a waste residue produced during tea production and processing as well as daily drinking,are rich in tea polyphenols.An efficient mechanochemical⁃assisted double aqueous⁃phase system extraction technique with selective extraction capability is developed for the extraction of tea polyphenols from green⁃tea residues.Experimental conditions are optimized through single factor and response surface optimization experiments.The optimal process conditions are determined as follows:mass fraction of ammonium sulfate is 18%,mass fraction of ethanol is 35%,liquid⁃to⁃solid ratio is 65 mL·g^(-1),milling speed is 468 rpm,and extraction time is 10 min.Under these conditions,the maximum yield of tea polyphenols is 50.01±0.26 mg·g^(-1),which approaches that by the traditional mechanochemical⁃assisted extraction(52.36±0.34 mg·g^(-1)).However,the product obtained by mechanochemical⁃assisted double aqueous⁃phase extraction contains 46.2%of solid extract,much higher than that obtained by traditional mechanochemical⁃assisted extraction(21.6%).In addition,the antioxidant capability of tea polyphenols extracted by mechanochemical⁃assisted double aqueous⁃phase extraction is significantly higher than that by the traditional method.