Extraction of Catechin Compounds from Green Tea with a New Green Solvent

An emerging green solvent called a deep eutectic solvent(DES) was applied to the extraction and determination of catechin(C), (+)epicatechin gallate(ECG) and (-)epigallocatechin gallate(EGCG) from Chinese green tea. After evaluating different combinations of them by extraction methods and DESs, a DES-based extraction method was established and optimized by a systematic investigation of the influencing factors. As a result, a total of 3.629, 35.25 or 114.2 mg/g catechin, (+)epicatechin gallate or ()epigallocatechin gallate were extracted respectively under optimal conditions with extraction efficiencies of 82.7%, 92.3% and 97.0%, respectively. By comparing with other common used solvents for extracting catechin compounds, DESs were proved to be potential extraction solvents for bioactive ingredients.