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
Indian tea culture the Yandaboo Treaty. In 1837, the first English tea garden was established at Chabua in Upper Assam; in 1840, the Assam Tea Company began the commercial production of tea in the region, run by indentured servitude of the local inhabitants. Beginning in the 1850s, the tea industry rapidly expanded, consuming vast tracts of land for tea plantations. By the start of the 20th century, Assam became the leading tea producing region in the world. But despite the discovery of the indigenous "Camellia sinensis" plant, the tea industry in India began with 42,000 seedlings germinated from a consignment of 80,000 seeds