Investigation on total poly phenols and caffeine contents in green and black tea and instant powder of them

Polyphenols by antioxidant properties in tea are responsible for the health. One of the major alkaloids witch found in tea leaves is caffeine. The purpose of this study was to compare the total polyphenols and caffeine contents in the varieties of green and black tea and instant types of them، which provided from tea garden of Lahijan from north of Iran. Caffeine contents of tea samples were extracted with chloroform as a solvent. Results showed that the average amount of total polyphenols within the range of 4. 8027 to 21. 6510 (g/100g dm)، decrease in green tea، instant black tea and black tea، respectively and comparison of the results showed that although there are differences between the obtained values، but the difference of the total amount of polyphenols in green tea and instant black tea is not significant (p<0/05). According to the results the average amount of caffeine decrease in the instant black tea، instant green tea، black tea and green tea، respectively and the difference of the amount of caffeine (2. 2026 to 5. 3232 g/100g dm)، in samples is significant (P<0/05).