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 Chinese cuisine during the reign of Harsha (r. 606–647) over North India, Indian envoys to Tang China brought two makers of sugar who successfully taught the Chinese how to cultivate sugarcane. Cotton also came from India as a finished product from Bengal, although it was during the Tang that the Chinese began to grow and process cotton, and by the Yuan Dynasty it became the prime textile fabric in China. During the earlier Southern and Northern Dynasties (420–589), and perhaps even earlier, the drinking of tea became popular in southern China. (Tea comes from the leaf buds of "Camellia sinensis", native to