Phenolic content in tea green tea. Catechins constitute about 25% of the dry mass of a fresh tea leaf, although total catechin content varies widely depending on species, clonal variation, growing location, season, light variation, and altitude. They are present in nearly all teas made from "Camellia sinensis", including white tea, green tea, black tea and oolong tea. Of all the catechins in tea, EGCG is the main subject of scientific study with regard to its potential health effects. 4-Hydroxybenzoic acid, 3,4-dihydroxybenzoic acid (protocatechuic acid), 3-methoxy-4-hydroxy-hippuric acid and 3-methoxy-4-hydroxybenzoic acid (vanillic acid) are the main catechins metabolites found in humans after consumption of green
Camellia sinensis Tea plants will grow into a tree if left undisturbed, but cultivated plants are pruned to waist height for ease of plucking. Two principal varieties are used, the small-leaved Chinese variety plant ("C. sinensis sinensis") and the large-leaved Assamese plant ("C. sinensis assamica"), used mainly for black tea. The Chinese plant (sometimes called "C. sinensis" var. "sinensis") is a small-leafed bush with multiple stems that reaches a height of some 3 meters. It is native to southeast China. The first tea plant to be discovered, recorded and used to produce tea 3,000 years ago, it yields some of the most