A method for separating and preparing EGCG from tea leaves

Abstract

The invention relates to a method for extracting epigallocatechin gallate (EGCG) from tea raw materials. The method comprises the following steps: soaking tea raw materials in warm water, extracting, making the extract liquid go through a macroporous resin column, then making the extract liquid go through a polyamide resin column, condensing the obtained liquid, crystallizing, carrying out suction filtration, washing, and drying in vacuum so as to obtain the EGCG. Tea raw materials are soaked in warm water, water with a temperature higher than the soaking temperature is used to carry out spray-extraction, and then a continuous column chromatography method is adopted to purify the extract. The continuous column chromatography method comprises the following steps: loading macroporous resin into a column, making the extract liquid go through the column to obtain an ethanol analysis liquid with a concentration of 15 to 30%, then making the ethanol analysis liquid go through a polyamide resin column, using ethanol with a concentration of 70 to 85% to carry out elution so as to obtain an elution liquid of EGCG, removing ethanol from the elution liquid, and carrying out condensation and crystallization so as to obtain the finished EGCG product. The EGCG content of the product can reach 98% or more, and the yield can reach 80% or more.

Description

technical field [0001] The invention relates to the field of tea processing, in particular to a method for separating and preparing EGCG from tea. Background technique [0002] Tea leaves refer to the leaves of Camellia sinensis (Linn.) O. Kuntze, the plant of the genus Theaceae. my country is the origin of tea. Catechin belongs to the flavan-3-ol compounds and is the main active ingredient in tea. Among them, the content of catechin in summer and autumn tea is relatively high. [0003] Tea leaves mainly contain 4 kinds of catechin compounds, namely epicatechin (Epicatechin, EC), epicatechin-3-gallate (Epicatechin-3-gallate, ECG), epigallocatechin (Epigallocatechin, EGC) and Epigallocatechin-3-gallate (EGCG). [0004] EGCG, the component with the highest content of catechins, accounts for 9%-13% of the gross weight of green tea. Because of its special stereochemical structure, it has a series of biological activities such as anti-aging, anti-allergy, anti-inflammation, a...

AI Technical Summary

Problems solved by technology

[0014] However, the above method has the following problems: (1) using oolong tea or even green tea polyphenols as raw materials for manufacturing, the processing of these tea leaves and the production process of tea polyphenols lead to significantly higher raw material costs, lower production rates, and higher overall cost of forming EGCG; (2) A large number of organic reagents such as metal salts and chloroform have been used in the process, which has brought a series of safety problems such as environmental pollution and unsafe operation, and EGCG products have potential safety hazards such as excessive solvent residues, which are not conducive to food production. Promotion with pharmaceutical and other industries