APPLICATION OF CAPILLARY ELECTROPHORESIS TO TEA QUALITY ESTIMATION

The qualitatively important components of green tea (theanine, caffein e, ascorbic acid, (-)-epicatechin, (-)-epigallocatechin, (-)-epicatech in gallate and (-)-epigallocatechin gallate) were analyzed simultaneou sly by using capillary electrophoresis. The running buffer used was be rate buffer (80 mM, pH 8.4) containing 50 mM of sodium dodecylsulfate. The extracts of green tea, oolong tea and black tea were analyzed usi ng this method. Green teas of different plucking dates and the leaf sa mples from different positions in one shoot were also measured using t his method. These results showed that this method will considerably sa ve time and labor for the analysis of these components, and is quite u seful for the quality estimation of teas (particularly of green tea) a nd characterization of fresh tea leaves. (C) 1998 Elsevier Science B.V .