Extraction of catechins and caffeine from different tealeaves and comparison with micellar electrokinetic chromatography  

作　　者：SONGGuanqun LINJinming QuFeng C.W.Huie 

机构地区：[1]ResearchCenterforEco-EnvironmentalSciences,ChineseAcademyofSciences,Beijing100085,China [2]DepartmentofChemistry,HongKongBaptistUniversity,KowloonTong,HongKong,China

出　　处：《Chinese Science Bulletin》2003年第22期2438-2443,共6页

基　　金：supported by the National Science Fund for Distinguished Young Scholars of China(Grant No.20125514);the National Natural Science Foundation of China(Grant Nos.50273046 and 20275043).

摘　　要：This work describes the simultaneous deter- mination of catechins and caffeine in green, black tealeaves and canned tea-drink using micellar electrokinetic chromatography. The catechins analyzed include (+)-catechin, (-)- epicatechin, (-)-epigallocatechin, (-)-epicatechin gallate and (-)-epigallocatechin gallate. Using UV absorption method at 280 nm, the limits of detections of catechins and caffeine are 10-6 mol/L, which is suitable for the real sample determination. Using this analytical method, the extraction of these compounds from the tealeaves with hot water is compared under different temperatures. The effects of temperature on the amount of catechins and caffeine extracted are evident, showing that (-)-epigallocatechin gallate is the most easiest to be extracted at 100℃. The stability of catechins and caffeine in stocking solution of tea-drink at 4℃ is also compared on five consecutive days. The contents of catechins and caffeine in green and black teas are discussed and the difference of the content between different tealeaves can provide a reference for the assessment of tea quality.This work describes the simultaneous deter- mination of catechins and caffeine in green, black tealeaves and canned tea-drink using micellar electrokinetic chromatography. The catechins analyzed include (+)-catechin, (-)- epicatechin, (-)-epigallocatechin, (-)-epicatechin gallate and (-)-epigallocatechin gallate. Using UV absorption method at 280 nm, the limits of detections of catechins and caffeine are 10-6 mol/L, which is suitable for the real sample determination. Using this analytical method, the extraction of these compounds from the tealeaves with hot water is compared under different temperatures. The effects of temperature on the amount of catechins and caffeine extracted are evident, showing that (-)-epigallocatechin gallate is the most easiest to be extracted at 100℃. The stability of catechins and caffeine in stocking solution of tea-drink at 4℃ is also compared on five consecutive days. The contents of catechins and caffeine in green and black teas are discussed and the difference of the content between different tealeaves can provide a reference for the assessment of tea quality.

关 键 词：咖啡因 儿茶酚 萃取法 茶叶 胶束电动套色版 

分 类 号：TS272.7[农业科学—茶叶生产加工]