Determination of Caffeine in Different Commercially Available Green and Black Teas

Abstract

Methyl derivatives of xanthine are a group of alkaloids commonly used for their effects as mild stimulants on various organ systems such as cardiovascular and central nervous system (CNS), respiratory system and skeletal muscles. The naturally occurring methyl xanthines are caffeine, theophylline and theobromine. The aim of this study was to determine content of caffeine in the green and black tea commercially available from Bosnianmarketsby simple, fast and economical methods. The simultaneous quantitative and qualitative determination was based on spectrophotometric UV/Vis method and thin layer chromatography (TLC) method. Content of caffeine in the green tea was in the range 33.90 to 110.73(mg/g), and in the black tea was in the range from 10.32 to 63.00 (mg/g). The highest content of caffeine was detected in the green tea of Slovenian manufacturer, and in the black tea of  Croatian  manufacture. Consuming a large amount of these types of tea could cause some health problems.