Latin name: Camellia sinensis (L.) Kuntze
Family: Theaceae (tea family)
Common names: Green tea
Part used: Tender leaves, buds and shoots of varieties of the species Camellia sinensis (L.) O. Kuntze, known to be suitable for making tea for consumption as a beverage (ISO 11287:2011)
Key constituents: Flavonoids: flavonols: quercetin, kaempferol, myricetin mainly as 3-O-glycosides Flavones: apigenin, luteolin as C-glucuronides Flavanols: (flavan-3-ols 10-25%): (-)-epicatechin (EC), (epicatechin-3-O-gallate (ECG), (-)- epigallocatechin (EGC) and (-)-epigallocatechin-3-O-gallate (EGCG) Phenolic acids: including among others, chlorogenic acid, gallic acid, theogallin, amino acids: 19 amino acids, amongst which theanine [5-N-ethyl glutamine (3% w/w)], terpene saponins (theafolia saponins): aglycones including among others, barringtogenol C, R1- barringenol, polysaccharides (13 %) and proanthocyanidins (tannins).
Green tea is processed and grown in a variety of ways, depending on the type of green tea desired. As a result of these methods, maximum amounts of health promoting compounds are retained. Tea plants can be grown in the sun or in the shade and are grown in rows that are pruned to produce tender shoots in a regular manner. These shoots are then harvested as the climatic conditions allow e.g. in East Africa tea grows year-round in other locations such as Japan there are only 3 harvests per year.
Green tea processing should conform to the International Standard ISO 11287:2011 and be produced by acceptable processes, notably enzyme inactivation (typically pan-firing or steaming and commonly rolling or cutting, followed by drying.
Green tea is commonly consumed in Asia but was introduced into Europe in the 17th century. Traditionally, green tea has been used for the relief of fatigue and weakness, as a diuretic and for stomach disorders.1 Green tea leaves have also been found to be an exceptionally abundant source of policosanol (PC), a mixture of bioactive long-chain aliphatic compounds.2