Catechin is a flavan-3-ol, a type of natural phenol and antioxidant found abundantly in tea, cocoa, and various fruits. It belongs to the catechin subgroup of flavonoids and exhibits strong free radical scavenging properties. In food science, catechins contribute to the astringency and bitterness of green tea and are studied for potential cardiovascular and anti-inflammatory benefits. Chemically, it features a benzopyran structure with multiple hydroxyl groups enabling hydrogen bonding and metal chelation. It is relatively stable under acidic conditions but can oxidize in alkaline environments or upon prolonged heating.