Evaluation of tea and coffee products commercialized in Egypt using HPTLC

Abstract

Tea and coffee have been consumed for hundreds of years ago for their flavour and stimulating properties. Nowadays, caffeine received an increasing interest in food and pharmaceutical industries due to its CNS stimulant properties, peripheral vasoconstriction, relaxation of the smooth muscle and myocardial stimulation. Caffeine constitutes an average of up to 4% of tea leaf and 1.5% of coffee bean. The aim of this study is to assess the quality of tea and coffee products present in the Egyptian market. Quality assessment was performed based on caffeine levels by using high performance thin layer chromatography (HPTLC). The results showed the quality variation among the products examined of both tea and coffee. With Ahmed tea London English breakfast showing the highest caffeine content (535 mg/ cup) and El Gawhara Green tea showing the lowest (3 mg/ cup). The used method is simple, rapid, reliable and suitable for evaluation of quality of caffeine containing preparations.