Tea

Literature References: Evergreen shrub or tree, Camellia sinensis (L.) O. Kuntze, Theaceae, also known as Thea sinensis. Tender leaves and buds used commercially to produce the beverage; tea extracts are also used in traditional medicine, esp for their antineoplastic, stimulant, and diuretic properties. Habit. Discovered in China 4-6000 yrs ago, also indigenous to India, Japan, Sri Lanka, Indonesia and other tropical and subtropical countries. Approx. 2.5 million tons of dried leaves are used in tea production each yr. Leaves are quickly steamed to prevent enzymatic oxidation in production of green tea, partially oxidized to a green/brown color in oolong tea, and rolled, sifted and oxidized to a copper color in black tea. Constit. Caffeine, theobromine, theophylline, amino acids, proteins, flavonoids, lignin, organic acids, chlorophyll, polysaccharides, polyphenols. Beneficial health effects have been linked to the polyphenols known as catechins, esp epigallocatechin gallate (EGCG), q.v. Determn of catechins: J. J. Dalluge, B. C. Nelson, J. Chromatogr. A 881, 411 (2000). Review of tea manufacture: M. A. Bokuchava, N. I. Skobeleva, Crit. Rev. Food Sci. Nutr. 12, 303-370 (1980); and plant history, tea chemistry and consumption: H. N. Graham in The Methylxanthine Beverages and Foods: Chemistry, Consumption, and Health Effects, G. A. Spiller, Ed. (Alan R. Liss, New York, 1984) pp 29-74; of chromatographic determn: A. Finger et al., J. Chromatogr.624, 293-315 (1992); of potential therapeutic antioxidant properties: L. A. Mitscher et al., Med. Res. Rev. 17, 327-365 (1997); of botany and horticulture: L. Manivel, Hort. Rev. 22, 267-295 (1998); of potential therapeutic dermatologic applications: A. F. Alexis et al., Int. J. Dermatol. 38, 735-743 (1999); of anti-cariogenic properties: J. M. T. Hamilton-Miller, J. Med. Microbiol. 50, 299-302 (2001); of inhibition of carcinogenesis: C. S. Yang et al., Annu. Rev. Pharmacol. Toxicol. 42, 25-54 (2002).