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
Korean tea tea to King Gyeongdeok and the Buddha. "Camellia sinensis" tea plants spread throughout the country in 828, when King Heungdeok received seeds from the Tang Empire and sent them to be planted on the Jirisan mountain. Tea was usually offered to the Buddha, as well as to the spirits of deceased ancestors. Tea culture continued to prosper during the Goryeo Dynasty. Tea offering was a part of the biggest national ceremonies, such as Yeondeunghoe and Palgwanhoe, and tea towns were formed around temples. During the reign of King Myeongjong (1131‒1202), Seon-Buddhist manners of ceremony prevailed. Jeong Mongju and other scholars