A new technology of preparation for EGCG
On the basis of traditional organic solvents extraction,equal volume of citric acid solution was used to make the EGCG.The result showed that the proportion of EGCG in tea polyphenols raised from 40%～50% to 80% now.Then,catechin monomer was isolated and purified by HSCCC with the purity above 98%.The common and new method were compared using two kinds of tea polyphends as raw materials.It demonstrated that under the same condition of sample volume,the yields of EGCG made by new method raised 169% compared with that using the common method.