Decrease in concentration of free catechins in tea over time determined bymicellar electrokinetic chromatography

Cancer chemoprevention is a new and important medical science and much inte rest has been focused on catechins, not only for their antioxidant activity , but also because of their known antimutagenic and antitumorigenic propert ies. Green tea and black tea, which are among the most popular beverages co nsumed worldwide, contain many different catechins. Due to the instability of catechins in solutions with neutral or basic pH values the concentration s of catechins in tea decrease in time. In this presentation we used micell ar electrokinetic chromatography to determine the real concentration of cat echins between 0 and 60 min after the tea was brewed. (C) 2001 Elsevier Sci ence B.V. All fights reserved.