Fermentation of
tea is an oxidation process of the polyphenolic substances presents
in tea leaves. This process starts as soon as leaf is macerated during
rolling. The key quality attributes of tea, i.e. catechins are localized
in the cell vacuoles of the undamaged tea leaf. The enzymes,
polyphenol oxidase (PPO) and peroxidase (PO) are responsible for
the oxidation of catechins