Tea is the most widely consumed drink in the world
other than water.1 Tea is made of Camellia sinensis
leaves and classi¢ed as green tea, black tea or oolong
tea according to the degree of fermentation.The tea leaf
contains polyphenolic £avonoids (over 30% of the dry
weight), most of which in green tea are £avanols, commonly known as catechins.2