Tea is a beverage made by steeping processed leaves, buds, or twigs of the tea bush (Camellia sinensis) in hot water for a few minutes. The processing can include oxidation (fermentation), heating, drying, and the addition of other herbs, flowers, spices, and fruits.There are four basic types of true tea: black tea, oolong tea, green tea, and white tea. The term “herbal tea” usually refers to infusions of fruit or herbs (such as rosehip, chamomile, or jiaogulan) that contain no C. sinensis. (Alternative terms for herbal tea that avoid the word “tea” are tisane and herbal infusion). This article is concerned exclusively with preparations and uses of the tea plant C. sinensis.Tea is a natural source of methylxanthines such as caffeine [1], catechins, and theanine. It has almost no carbohydrates, fat, or protein. It has a cooling, slightly bitter and astringent taste.
