Al（3＋）沉淀法制备茶多酚工艺研究

目的]为开发利用茶多酚提供试验依据。方法]以绿茶为原料,用乙醇作提取剂,通过超声波辅助提取得到茶多酚浸提液,然后通过单因素试验和正交试验确定Al3＋沉淀法制备茶多酚的最佳沉淀条件。结果]单因素试验结果表明：乙醇的浸提效果优于沸水;茶叶与AlCl3.6H2O的质量比为1∶0.50时,茶多酚的沉淀率最高,为96.13%;pH为5.7时,茶多酚的沉淀率最高;20 min以内,茶多酚的沉淀率随时间的延长而增加,20 min以后,沉淀时间对茶多酚沉淀率的影响不大。正交试验结果表明：茶多酚的最佳沉淀条件为茶叶与沉淀剂AlCl3.6H2O质量之比1∶0.50,pH 5.7,沉淀时间20 min,该工艺条件下茶多酚的沉淀率达97.38%±0.35%。结论]该提取工艺简单,无毒性,产品得率较高,纯度好。

Study on the Production Technology of Tea Polyphenol through Precipitation with Al3+

Objective]The purpose was to supply experimental foundation for developing and using tea polyphenol.Method]With green tea as raw material,alcohol as extractant,the tea polyphenol was extracted through ultrasonic-assisted extraction and then the optimum sedimentation condition for producing tea polyphenol through precipitation with Al3+ was confirmed through single factor experiments and orthogonal test.Result]The results of single factor experiments showed that the extraction effect of alcohol was better than boiling water;when the mass ratio of tea to AlCl3·6H2O was 1∶0.50,the precipitation rate of tea polyphenol was highest,being 96.13%;when the pH value was 5.7,the precipitation rate of tea polyphenol was highest;the precipitation rate of tea polyphenol was increased as the precipitation time was extended in 20 min and the influence of precipitation time on precipitation rate of tea polyphenol was little after 20 min.The results of orthogonal test showed that the optimum precipitation condition of tea polyphenol was as follows: the mass ratio of precipitant AlCl3·6H2O to tea was 0.50,the pH value was adjusted to 5.7 and the precipitation time was 20 min.Under this technological condition,the precipitation rate of tea polyphenol reached 97.38%±0.35%.Conclusion]This extraction technology was simple and non-hazardous and the yield rate and purity of its product were higher.