普洱茶中茶多糖提取工艺的研究

Extraction technology of tea polysaccharide in Pu'er tea

目的建立一种普洱茶中茶多糖的提取工艺。方法以普洱茶为材料,采用水提醇沉法,研究了浸提温度、浸提时间、浸提次数、乙醇浓度4个因素对普洱茶中茶多糖提取率的影响,并通过正交实验确定茶多糖的最佳提取工艺。且用此提取工艺测定市售不同级别普洱茶中茶多糖含量。结果普洱茶中茶多糖的最佳提取工艺为:浸提温度90℃,浸提时间40 min,浸提次数3次,乙醇浓度80%。该提取工艺重复性好,吸光度与葡萄糖含量呈良好的线性关系(n=5),线性范围0.02~0.10 mg/L(r2=0.9999)。实验也发现,普洱茶的嫩度越低,茶多糖的含量越高。结论本方法简便、快捷、重复性好,可作为茶叶多糖原材料和产品质量控制的方法。

Objective To establish a extraction process of tea polysaccharide in Pu＇er tea. Methods The influences of extraction temperature, extraction time, extraction times and ethanol concentration on the extraction rate of tea polysaccharide in Pu＇er tea were studied with the use of Pu＇er tea as the material. The optimal extraction process of tea polysaccharide was determined by orthogonal experiment. The content of tea polysaccharide in different grades of Pu＇er tea was determined by the extraction process. Results The optimal extraction process of tea polysaccharide in Pu＇er tea was as follows： extraction temperature was 90 ℃, extraction time was 40 min, extraction times was 3 times, and ethanol concentration was 80%. The extraction process was repeatable. There was a good linear relationship between absorbance and glucose content（n=5）, with a linear range of 0.02~0.10 mg/L（r2=0.9999）. The experiment also found that the lower the tenderness of Pu＇er tea, the higher the content of tea polysaccharide. Conclusion The extraction process is simple, rapid and repeatable, which can be used as a method for the quality control of tea polysaccharide raw materials and products.