title: Extraction of Epigallocatechin Gallate and Epicatechin Gallate from Tea Leaves Using β-Cyclodextrin.
abstract: Use of organic solvents to extract phenolic compounds from plants may result in environmental pollution and cause health problems in persons. Replacing organic extraction solvents by green extracting agents without affecting the extraction yield is one of the most pressing problems to be solved. The aim of this study is to evaluate the capacity of β-cyclodextrin (β-CD) to recover phenolic compounds from tea leaves. The extract obtained using the ethanol/water mixture presented the highest total phenolic content, followed by those obtained using β-CD solution and water. HPLC analysis of the extracts showed that the addition of β-CD to the extracting agent had a selective effect on the extraction of epigallocatechin gallate (EGCG) and epicatechin gallate (ECG). The extraction yield of EGCG and ECG using 15 g/L β-CD were higher than that obtained using water and 50% ethanol. Molecular docking results indicated that the molecules of EGCG and ECG were more inclined to interact with β-CD than epigallocatechin, epicatechin, and gallocatechin. The impact of β-CD concentration, temperature, and time on EGCG and ECG extraction from tea leaves was investigated and the maximum amount of EGCG (118.7 mg/g) and ECG (54.6 mg/g) were achieved when extracted with 25 g/L aqueous β-CD solution at 60 °C for 60 min. The present study indicates that aqueous β-CD can be used as an alternative to organic solvents to recover EGCG and ECG from tea leaves.
authors.affiliation: College of Food Science and Engineering, Northwest A&F Univ., Yangling, Shaanxi, 712100, China.
authors.forename: Lu
authors.initials: L
authors.lastname: Cui
authors.affiliation: College of Food Science and Engineering, Northwest A&F Univ., Yangling, Shaanxi, 712100, China.
authors.forename: Yuxuan
authors.initials: Y
authors.lastname: Liu
authors.affiliation: College of Food Science and Engineering, Northwest A&F Univ., Yangling, Shaanxi, 712100, China.
authors.forename: Ting
authors.initials: T
authors.lastname: Liu
authors.affiliation: College of Food Science and Engineering, Northwest A&F Univ., Yangling, Shaanxi, 712100, China.
authors.forename: Yahong
authors.initials: Y
authors.lastname: Yuan
authors.affiliation: College of Food Science and Engineering, Northwest A&F Univ., Yangling, Shaanxi, 712100, China.
authors.forename: Tianli
authors.initials: T
authors.lastname: Yue
authors.affiliation: College of Food Science and Engineering, Northwest A&F Univ., Yangling, Shaanxi, 712100, China.
authors.forename: Rui
authors.initials: R
authors.lastname: Cai
authors.affiliation: College of Food Science and Engineering, Northwest A&F Univ., Yangling, Shaanxi, 712100, China.
authors.forename: Zhouli
authors.initials: Z
authors.lastname: Wang
mesh_terms: D028241:Camellia sinensis / Q000737:chemistry*; D002392:Catechin / Q000031:analogs & derivatives* / Q000737:chemistry / Q000302:isolation & purification; D005591:Chemical Fractionation / Q000295:instrumentation / Q000379:methods*; D002851:Chromatography, High Pressure Liquid; D062105:Molecular Docking Simulation; D010636:Phenols / Q000737:chemistry / Q000302:isolation & purification; D010936:Plant Extracts / Q000737:chemistry / Q000302:isolation & purification*; D018515:Plant Leaves / Q000737:chemistry*; D047392:beta-Cyclodextrins / Q000737:chemistry
chemical_list: D010636:Phenols; D010936:Plant Extracts; D047392:beta-Cyclodextrins; D002392:Catechin; C062669:epicatechin gallate; C045651:epigallocatechin gallate
keywords: epicatechin gallate; epigallocatechin gallate; extraction; tea leaves; β-cyclodextrin