Study on determination of tea polysaccharide content in Pu'er tea and its extract.

A method was developed for the rapid determination of water-soluble tea polysaccharide content in Pu'er tea and its extract.Firstly,Pu'er tea leaves were extracted through water,or Pu'er tea powder was directly dissolved into water;secondly,the extraction solution was sedimentated with 80% ethanol,and then they were hydrolyzed by hydrochloric acid solution(0.5 mol/L) for 30 min at 40 ℃;thirdly,they were isolated and eluted through polyamide chromatographic column;finally,the water-soluble tea polysaccharide content was determined by using phenol-sulfuric acid method.The results indicated that this method could effectively wipe off the interference from tea pigment etc.in Pu'er tea,and accurately determine the content of water-soluble tea polysaccharide.