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
Camellia japonica a long time. One of the most important plants related to "Camellia japonica" is the "Camellia sinensis", which is the plant tea comes from. This plant is not usually grown in gardens because it has small white flowers, unlike the "Camellia japonica", which has larger, more beautiful flowers. It is not seen in art as often as the "Camellia japonica", but it is shown in a painting called the "Song Hundred Flowers" which hangs in the Palace Museum in Beijing. "Camellia sinensis" may have been used as medicine during the Shang Dynasty. It was first used for drinking during the