富含表没食子儿茶素（EGC）和表没食子儿茶素没食子酸酯（EGCG）的绿茶提取物的制备及其抗氧化活性

Preparation and antioxidant activity of green tea extract enriched in epigallocatechin (EGC) and epigallocatechin gallate (EGCG).

作者信息

Hu Jianhui, Zhou Danrong, Chen Yuqiong

机构信息

College of Horticulture and Forestry Science, Huazhong Agricultural University, Key Laboratory of Horticultural Plant Biology, Ministry of Education, No. 1 Shizishan Street, Hongshan District, Wuhan City, Hubei Province, China.

出版信息

J Agric Food Chem. 2009 Feb 25;57(4):1349-53. doi: 10.1021/jf803143n.

DOI:10.1021/jf803143n

PMID:19182914

Abstract

The present study investigated effects of solvents, temperature, and duration on extracting efficiency of catechins from green tea by an orthogonal test. The results suggested that extraction of epigallocatechin gallate (EGCG) was highly dependent on these factors, whereas that of epigallocatechin (EGC) was significantly affected by duration and solvent (P < 0.05). Effects of these factors on epicatechin (EC), catechin (C), and epicatechin gallate (ECG) were not significant. A two-step preparation was adopted to produce green tea extract enriched in EGC (GTE-EGC) and green tea extract enriched in EGCG (GTE-EGCG). The optimum conditions for GTE-EGC were that green tea was brewed in 75% ethanol at 30 degrees C for 10 min, whereas for GTE-EGCG the same tea was brewed in 35% ethanol at 90 degrees C for 60 min. Compared with GTE-EGC, GTE-EGCG had EGCG increased by 110.42%, whereas EGC decreased by 40.38% with EC and ECG being unchanged. Most importantly, GTE-EGCG possessed greater antioxidant activity (in vitro) than GTE-EGC.

摘要

本研究通过正交试验研究了溶剂、温度和时间对从绿茶中提取儿茶素效率的影响。结果表明，表没食子儿茶素没食子酸酯（EGCG）的提取高度依赖于这些因素，而表没食子儿茶素（EGC）的提取则受时间和溶剂的显著影响（P < 0.05）。这些因素对表儿茶素（EC）、儿茶素（C）和表儿茶素没食子酸酯（ECG）的影响不显著。采用两步法制备富含EGC的绿茶提取物（GTE - EGC）和富含EGCG的绿茶提取物（GTE - EGCG）。GTE - EGC的最佳条件是绿茶在75%乙醇中于30℃冲泡10分钟，而GTE - EGCG的最佳条件是同一茶叶在35%乙醇中于90℃冲泡60分钟。与GTE - EGC相比，GTE - EGCG中EGCG增加了110.42%，而EGC减少了40.38%，EC和ECG不变。最重要的是，GTE - EGCG在体外具有比GTE - EGC更强的抗氧化活性。