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
Tea production in the United States Tea production in the United States "Camellia sinensis" can be grown in warmer parts of the United States and currently the US mainland has a relatively large plantation with full mechanization in Charleston, South Carolina, and numerous small number of commercial tea gardens and smaller artisan operations that currently pick tea by hand. Many smaller sites are looking to mechanize, at least partially, within the next 5 years. Some growers feel that tea production is not viable without some mechanization, but there is evidence that unmechanized tea production is viable, albeit with lower net profit margins. Most domestically grown teas