Caffeine and Total Polyphenol Contents of Market Tea Cultivated and Processed in Bangladesh

ABSTRACT

Objective: The aim of this study was to determine the contents of caffeine and total polyphenol in six brands of market tea cultivated and processed in Bangladesh. Methods: Caffeine and polyphenol contents were determined by solvent extraction (AACC) and the International Organisation for Standardisation Method (ISO) 14502-1 respectively. Results: Caffeine contents of the different tea samples ranged between 0.99 ± 0.17% to 2.08 ± 0.16% (g/100g materials), while that of total polyphenol was from 36.90 ± 1.39% to 17.29 ± 2.30% of gallic acid equivalents (GAE). The order of caffeine concentration in tea samples was found as follows Organic Black Tea > Taaza Tea > Organic Green Tea > Magnolia Tea > Organic Zinger Tea > Organic Tulsi Tea. The polyphenol concentration in the tea samples was highest in Organic Green Tea followed by Taaza Tea and the rest as follows Magnolia Tea > Organic Black Tea > Organic Zinger Tea > Organic Tulsi Tea. An indicative difference in amounts of caffeine and polyphenols for different tea brand samples is seen in this study. Conclusion: This systematic screening provides information to producers as well as consumers on the quantities of caffeine and polyphenols in commercial tea available in the markets of Bangladesh.