ABSTRACT
The tea bush and in particular its young leaves contain a high concentration of polyphenols and oxidative enzymes, thus the young leaves are better for tea manufacture. Tea polyphenols, previously called tea tannins, are also known as tea avonoids. Among the polyphenols in fresh tea leaves, catechins are the predominant form of polyphenols, which account for 12-24% of the dry weight. Besides catechins, avonol, and their glycosides, anthocyanidin and leucoanthocyanidin, phenolic acids and depsides are also present. Their typical concentrations are shown in table 8.1.1 These phenolic compounds are directly or indirectly associated with the characteristics of tea, including its color, taste, and aroma.
