Study On Catechin Active Ingredient Of Tea Residue And Its Application

In this thesis, the method of extracting catechins and preparation of theaflavins with tea residue was studied. Base on determination of the major components of raw materials green tea residue was determined as experimental material.Then focused on the extraction and oxidation process and purification of catechins in the tea residue. Meanwhile,antioxidant effects of catechin and theaflavins were studied.Through single-factor design of experiments and response surface analysis,the best extraction conditions was that:liquid ratio of1:50,100℃and45min.According to compare the effect of five types of chemical oxidants the optimal chemical oxidant of catechins was the solution of FeK3(CN)6and NaHCO3(solution FeK3(CN)6:NaHCO3=100:3:1). As theaflavin content to the study of indicators, through the oxidation of single-factor experiments and orthogonal test,the optimal oxidation conditions were the adding volume of oxidants [FeK3(CN)6] of3%,20℃(at room temperature),20min. The results of enzymatic preparation showed that the optimal oxidation conditions of the polyphenol oxidase were the amount of enzyme added of2.5%,40℃,20min, pH value of5.5. By comparison of chemical oxidation method and enzymatic oxidation, ultimately the chemical oxidation method was determined to prepare the theaflavins.Then,the purification technologies of theaflavins and catechin were preliminarily studied. Macroporous resin HPD600was selected from6kinds of macroporous resins to purify theaflavins and catechin.In the end,the effects of antioxidant of theaflavins and catechin,4kinds of antioxidants were chosen as control.And the results showed that the antioxidant of theaflavins and catechin was better than TP and BHA and rosemary. The effects of antioxidant was remarkable.