Of all the promising cancer preventive phytochemical-rich plants being explored by research scientists, green tea is arguably the most aggressively pursued. But cancer prevention represents only a fragment of the shielding effects of green tea. Let's explore the history, applied chemistry, and chemopreventive actions of green tea and its constituent defenders, the polyphenol catechins. Black Tea is produced by the fermentative oxidation of green tea's astringent phytochemicals, the catechin polyphenols, producing related compounds called theaflavins . Oolong tea results from a partial oxidation of green tea polyphenols.
Green tea is produced with the goal of preserving the leaf polyphenols.
The polyphenols are the active players in green tea, mediating both taste profile and biological actions. From a chemical perspective, green tea polyphenols are catechins, phytochemicals composed of several linked ring-like structures. Attached to each structure are chemical tags called phenol groups, and because there are many phenol groups, these catechins are called polyphenols. Other components include the unique amino acid theanine, carotenoids, chiorophyll and caffeine. EGCG has been put to use as a potent antioxidant, both in food production and in animal research studies.