Extraction of major catechins from green tea.

Green tea is the second most popular beverages in the world next only to water.
Due to its associated health benefits, it has drawn the attention of many
researchers. These beneficial health effects are mainly owing to the presence of
catechins, a group of tea polyphenols which accounts to 12-20% of the dry
weight of the green tea leaves. The major green tea catechins are:
Epigallocatechin gallate (EGCG), Epigallocatechin (EGC), Epicatechin gallate
(ECG) and Epicatechin (EC). Apart from beverage preparation, green tea extract
can be extensively used in the production of functional and health foods.