Tea extraction methods in relation to control of epimerization of tea catechins

• DOI: 10.1002/jsfa.2913
• Publication Date: 2007-04-27T11:54:58Z
• Authors: Huiling Liang; Yuerong Liang; Junjie Dong; Jianliang Lu
• Keywords: Gallate; Epicatechin gallate; Epimer; Water extraction

Abstract Effect of water temperature and ethanol concentration on epimerization extractability tea catechins was investigated. The results showed that epigallocatechin gallate (EGCG) epicatechin (ECG) were partially epimerized into gallocatechin (GCG) catechin (CG), respectively, when extract heated in solution at 100 °C for 2 h or dry extracted °C. the inhibited if as solid powder 50% (v/v) 80 below. When water, increased with increase extraction up to °C, but there no statistically significant difference total between teas using solutions, highest obtained 75% fresh leaf. In order reveal real profiles be tested, should 10 min, while leaf min. For commercial extraction, controlled is used solvent. Copyright © 2007 Society Chemical Industry