Selective isolation of epigallocatechin‐3‐gallate from green tea

Abstract

Epigallocatechin‐3‐gallate is a primary bioactive constituent part of green tea that has preservative influence on human health. Due to the small amounts and high expenditure of trading epigallocatechin‐3‐gallate, it is necessary to improve a trade‐operational and influential preliminary method to purify epigallocatechin‐3‐gallate from natural funds. This study suggests that the polyamide column separation is a simple method for large‐scale separation and purification of epigallocatechin‐3‐gallate from green tea for food applications. The most important innovation in this study is that high standard yield and high purity epigallocatechin‐3‐gallate are obtained from polyamide column after catechin mixture is obtained by supercritical fluid extraction. The purity of caffeine is checked with thin‐layer chromatography and high performance thin‐layer chromatography the resulting decaffeinated catechin mixture is isolated on polyamide support column using ethanol: water mixture as eluent. Epigallocatechin‐3‐gallate is isolated from the mixture as pure. The pure epigallocatechin‐3‐gallate is obtained starting with a mixture of 75% ethanol and 25% water elution.