ADVERSE EFFECTS OF TEA METABOLITES EXTRACTED DURING INDIAN HOUSEHOLD TEA PREPARATIONS ON DIGESTIVE ENZYMES AND IRON

The study encompasses secondary metabolites and antioxidant potential estimation of green & black tea during infusions under Indian household tea making processes. Tea infusions for 5, 10 & 15 minutes in controlled (at 60, 80 & 100°C temperature) and uncontrolled environment (normal household preparation) were studied. Controlled infusions revealed optimised extraction conditions of each metabolite and served as the platform, based on which, normal household process was compared. Study suggests effective & maximal utilization of metabolites for minimizing nutrient loss by correlating inhibitory roles of total polyphenols and total tannins with the digestive enzymes and iron and calculated the volume of tea required for certain % of enzymatic & iron inhibitions. Green tea is more strong non-haem iron inhibitor (3.7- 4.6 times stronger than black tea) due to more total tannins and the volume of green tea required is almost half (48-55% lesser) than that of black variety to have same enzymatic inhibition % (due to more available polyphenols), thus making it almost twice (1.82-2.07 times than black) as effective as black tea to act as antidiabetic and antiobesitic agents by their inhibitory actions upon ?-amylase & lipase respectively. Drinking of green tea may not be suitable for the malnourished population, especially, in the Indian subcontinent due to higher available polyphenols & tannins possessing adverse effects on digestive enzymes & iron.