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
History of tea the Chinese monopoly on tea. ""Camellia sinensis" originated in southeast Asia, specifically around the intersection of latitude 29°N and longitude 98°E, the point of confluence of the lands of northeast India, north Burma, southwest China and Tibet. The plant was introduced to more than 52 countries, from this 'centre of origin'." On morphological differences between the Assamese and Chinese varieties, botanists have long asserted a dual botanical origin for tea; however, statistical cluster analysis, the same chromosome number (2n=30), easy hybridization, and various types of intermediate hybrids and spontaneous polyploids all appear to demonstrate a single place of origin for