绿茶茶渣半纤维素的提取及组成性质研究

Study on the extraction, separation and composition of tea-leaf hemicelluloses

摘要: 目的:从绿茶茶渣中分离半纤维素,研究其组成性质。方法:利用碱性过氧化氢法浸提、乙醇沉淀提取得到茶渣半纤维素。红外光谱法测定其糖苷键类型;离子色谱法分析其单糖组成;高效凝胶色谱法测定其相对分子质量。结果:红外光谱中半纤维素具有糖类物质的特征吸收峰;茶渣半纤维素主要由葡萄糖、半乳糖、阿拉伯糖组成,另外还含有少量的鼠李糖、木糖和氨基半乳糖。高浓度乙醇沉淀的茶渣半纤维素相对分子量在2000左右;结论:该茶渣半纤维素是一种酸性半纤维素多糖。

Abstract: Objective:To get hemicelluloses polysaccharide from green tea-leaf and study the composition of the polysaccharide. Methods:The hemicelluloses was obtained from tea-leaf that without most water soluble composition by ways as follows:Alkaline hydrogen peroxide extraction, graded ethanol precipitation. The form of glycosidic bond was determined by IR. The monosaccharide components of hemicelluloses were determined by Ion Chromatograph. Its MW was measured by HPGFC. Results:Typical absorption of sugar was shown in the IR spectrum. Glucose, galactose, arabinose, rhamnose, mannose and galactosamine. The MW of the hemicelluloses which were precipitated by high concentrations of ethanol was estimated 2000. Conclusion:The hemicelluloses extract by alkaline hydrogen peroxide was a kind of acidic hemicelluloses polysaccharide.