茶多酚的离子沉淀法提取及其成分分析

Study on Extraction of Tea Polyphenols by Ion Precipitation Technology and Analysis on Ingredients of the Product

探讨了离子沉淀法提取茶多酚的最佳工艺条件,并运用高效液相色谱对茶多酚产品进行了成分分析。通过正交实验确定了最佳浸提方案,即用60%乙醇-水溶液在70℃浸提茶叶2次,投料比为1:25,茶多酚的最终浸出量可达茶叶的22.5%。选用(Al3++Zn2+)为复合沉淀剂,以NaHCO3溶液调节pH值=5.5～6.5,进而以HCl溶液转溶沉淀,结果表明,茶多酚的产率提高到11.8%,纯度达到99.5%。

The preferred ion precipitation technology for extracting tea polyphenols (TP) was investigated, and the ingredients of the product were analyzed with high performance liquid Chromatography. The optimal operation conditions of soaking TP were found by orthogonal experiment, that is, 60 % ethanol as solvent, leaching 2 times, with the ratio of tea and solvent 1:25. Under the conditions, the maximum leaching rate of TP reached the 22.5 % of tea. In the precipitation experiment, the preferred conditions of precipitation method are: (Al^(3+) + Zn^(2+)) as ion-coprecipitating agent, regulating pH value to 5.5～6.5 with NaHCO_3, dissolving precipitation with HCl. It showed that the yield and the purity of TP were improved to 11.8 % and 99.5 % respectively.