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
Chinese tea culture or "cha wenhua" ("tea culture"). The word "cha" (茶) denotes the beverage that is derived from "Camellia sinensis", the tea plant. Prior to the 8th century BCE, tea was known collectively under the term 荼 (pinyin: tú) along with a great number of other bitter plants. These two Chinese characters are identical, with the exception of an additional horizontal stroke in the Chinese lettering 荼, which translates to tea. The older character is made up of the radical 艸 (pinyin: cǎo) in its reduced form of 艹 and the character 余(pinyin: yú), which gives the phonetic cue. There are several