The Hydrolysis Of Ester Theaflavins Into Simple Theaflavin By Hydrolase And The Functional Properties' Evaluation Of Simple Theaflavin

Theaflavins is a product of tea fermentation that can be extracted from the black tea, and can also be synthesis from catechin by chemical or biological methods. It can be roughly divided into two categories:Ester theaflavins with Gallate ester (TF-3-G,TF-3'-G,TFDG) and Non-ester theaflavins without Gallate ester (TF). Theaflavins' value lies in its functions of anti-oxidant, hypolipidemic, anti-cancer, low-Cholesterol etc. This article focuses on the enzymatic degradation of Ester theaflavins into TF, and TF's lipid-lowering properties and antioxidant activity in vitro.The research was designed by using enzymes including tannase, lipase, porcine pancreatic lipase, papain, trypsin, glucoamylase, pectinase and a-amylase, to compare the hydrolytic effect of ester theaflavins (TFDG) and to obtain the optimum reaction conditions of the best hydrolase was selected. Results showed that the optimum condition is as follows:temperature of reaction system 40℃, pH5, enzyme concentration 2.4 mg/mL, reaction time 120min.The content of TF increased from 39.81 mg/g to 199.84 mg/g under these optimum conditions.Compared the adsorption property of XDA-1, D101, HP-20, AB-8, D202, D14, NKA-9 and polyamide to TFs in static state, and certain the best resin to purify TFs is D14. Dynamic optimizations of D-14 are:the sample flow rate 2BV/h, the sample concentration 0.33mg/mL, elution gradient 10%-30%-80%.Using 0.1% lipid emulsion to establish a Hyperlipidemia model in human liver L-02 cell. MTT tests are applied to check the toxicity of TFs to the human liver L-02 cell, and the appropriate dosages are determined. Add a series of gradient TFs to culture the human liver L-02 cell. Detecting the content of total triglyceride (TG) and total cholesterol (TC) by biochemical analyzer. T-AOC test box, H2O2 test box, Hydroxyl radical test box and O2 test box are used to disclose the anti-oxidant property of TFs in vitro.The water solubility at the temperature of 4℃,10℃,20℃,30℃of TFs are applied. And the stabilities at Different colors of light, different temperatures, different pH values are also applied.