茶叶酸性多糖的分离、纯化及其理化性质研究

Isolation, Purification and Physico-chemical Properties of Acidic Polysaccharides from Green Tea

采用水提醇沉法从采自江西婺源的粗老绿茶中提取茶叶多糖,通过Sevag法脱蛋白得到精制茶叶多糖,应用高效凝胶渗透色谱法(high performance gel permeation chromatography,HPGPC)分析茶叶多糖纯度并测定其分子质量,进一步测定茶叶多糖的糖含量、蛋白质含量、单糖组成、糖醛酸组成等理化指标,同时对其进行紫外和红外光谱扫描,考察其光谱性质。结果表明:该茶叶多糖组分为均一性高的酸性多糖组分,分子质量约为289 734 D,糖含量为55.1%,蛋白质含量为1.8%。该茶叶多糖酸性组分主要由鼠李糖、核糖、阿拉伯糖、甘露糖、葡萄糖和半乳糖组成,其物质的量比为1.26∶3.18∶4.08∶1.00∶1.52∶3.92,该茶叶多糖酸性组分中含有大量半乳糖醛酸,含量为33.5%。

Tea polysaccharides(TPS) were extracted and purified from green tea from Wuyuan of Jiangxi province. The purity and molecular weight(Mw) were determined by high performance gel permeation chromatography(HPGPC). The contents of sugar and protein, monosaccharide compositions, and uronic acid composition were determined as well. UV and IR spectroscopy were used for determining their spectroscopic properties. The results showed that the composition was highly homogeneous acidic polysaccharides. The Mw was 289 734 D, the content of polysaccharide was 55.1%, and the content of protein was 1.8%. This polysaccharide was mainly composed of rhamnose, ribose, arabinose, mannose, glucose and galactose with a molar ratio of 1.26:3.18:4.08:1.00:1.52:3.92. The major uronic acid was galacturonic acid with a relative content of 33.5%.