Catechin

Catechin is a catechol-type flavanol which occurs in tea and many other foods and beverages, including cocoa, wine and fruits. Catechins are thought to have beneficial effects on health because of their apparent antimicrobial activity, antioxidative activity and anticancer properties observed in laboratory studies. They also contribute astringency and pleasant bitterness to tea, wine and chocolate, shaping their sensory character. Green tea is the richest common source, and brewing conditions strongly affect how much is extracted. Cocoa and dark chocolate owe part of their bite and reputation to their catechin content.