Separation And Purification Of EGCG From Tea

The EGCG are the important ingredients in the tea, which have been used widely in medicine care, food additive field and so on. Large numbers of EGCG are needed, so extraction process of the extraction and purification of EGCG have to become more advanced. Many difficult problems aren't still solved during purification of EGCG. It's more difficult to separate water-solubility object of EGCG and ECG succedly. at the same time, different experiment conditions can effect on it greatly.Fresh old age tea leaves are used in the experiment. Negative pressure cavitation suspension solid to liquid technology is used to effectively strengthen EGCG extracting. The paper studies on further purify of EGCG by Silica gel column chromatography. The factors effecting on the extraction and purification of EGCG are studied such as initial water content of Silica gel,size of grain,ratio of diameter and height and flow rate,water content of mobile phase,charge number of Silica gel and so on. Finally the high purity of EGCG is obtained. At the same time, Silica gel column chromatography shows its practicability and energy saving. The process for extracting and purifying EGCG is simple, short-cycle and low cost. The technology is valued as a new technology to generalize in producing high-purified EGCG, which can be used in the industrial production in the future.The optimum conditions of experiment and magnifying test were as followed:1. The optimum process of extraction:Fresh old age tea leaves was killed by hot water.The extraction yield of EGCG was 2.514% by Negative pressure cavitation suspension solid to liquid technology.2. The optimum process of purification:Elution solvent was acetic ether: petroleum ether: acetic acid solvent contained water about two percent 7.5: 2.5: 0.5; initial water content of Silica gel was 10%; 200～300 mesh silica gel; ratio of diameter and height was 1:10; flow rate 80mL/min; charge number of Silica gel was 1gEGCG/20g.By the above technology, water-solubility object of EGCG and ECG was separated succeedly. purity of EGCG and ECG was 98.15% and 85% and recovery was 71.35%.