Theanine and Caffeine content of infusions prepared from commercial tea samples

Abstract

Thirty-seven commercial white, green, oolong, black, and pu-erh tea samples were analyzed for caffeine and theanine contentWhile the caffeine content was similar, the theanine contents of black teas were slightly lower and practically zero in pu-erhThe great variability of these two compound within the tea categories allows no discrimination of tea types based solely on theanine and caffeine quantificationContrary to the previous data, the way of processing has no determining effect on theanine content. FigureAbbreviations used: CZE: Capillary zone electrophoresis, DAD: Diode array detector, EEG: Electroencephalography, GC: Gas chromatography, HPLC: High-performance liquid chromatography, IR: Infrared spectroscopy, MEKC: Micellar electrokinetic capillary chromatography, MS: Mass spectrometry, RP: Reversed phase, RSD: Relative standard deviation, SD: Standard deviation, TLC: Tile liquid chromatography, UV: Ultraviolet.