ABSTRACT
Tea, made of the leaves of the plant Camellia sinensis, Theaceae, has been used for medicinal purposes in ancient days and is now a popular beverage worldwide. Depending on the processing of the tea leaves, tea is classied into three major types: green tea, black tea, and oolong tea, which account for 20%, 78%, and 2% of the world’s tea production, respectively. Green tea is mainly produced and consumed in Asian countries such as China and Japan. Black tea is produced in South Asia, South America, and Africa and consumed worldwide. Oolong tea is mainly produced and consumed in southeast China, Taiwan, and Japan (Balentine et al. 1997; Sang et al. 2011).
