The official botanic name is Camellia sinensis, but the Chinese originally called it Kia. As it is know somtimes the 6th century AD the name evolved into Cha, when it arrived into the West it became Té which is still the name for tea in many countries. Camellia sinensis is an evergreen plant that grows mainly in tropical and subtropical climates, but some varieties can also tolerate marine climates.
The phrase herbal tea or an extended meaning of the word tea usually refers to infusions of fruit or herbs made without the tea plant. They vary from one region to another, depending the local plants, and that's not the subject of the article.
Tea plants are native to East and South Asia, somewhere around the meeting points of the lands of northeast India, north Burma and southwest China, the Chinese being the first to use it (as it's known to date). The scientific analysis indicates that there is likely a single place of origin for Camellia sinensis: an area including the northern part of Burma, and Yunnan and Sichuan provinces of China. It is said that tea drinking likely began on the territory of modern day Yunnan province during the Shang Dynasty (1500 BC–1046 BC), as a medicinal drink (because of a medical text written by Hua T'o), then it spread to Sichuan as it is consumed today (boiling tea leaves into water without adding other leaves or herbs).
In Europe tea was first introduced to Portuguese priests and merchants in China during the 16th century, it became popular in Britain during the 17th century. Later the British introduced tea to their Indian colonies, in order to compete with the Chinese monopoly on tea.
Teas are generally divided into categories based on how they are processed. There are at least six different types of tea: white, yellow, green, oolong (or wulong), black (red tea in China) and post-fermented tea (black tea in China). The most commonly found on the market are white, green, oolong and black.
It is known that without careful moisture and temperature control during manufacture and packaging, the tea may become unfit for consumption due to the growth of undesired molds and bacteria. After picking the leaves of Camellia sinensis begin rapidly to wilt and oxidize, so they have to be dried immediately. Handling without care it may alter the taste and make it undesirable: the leaves turn progressively darker as their chlorophyll breaks down and tannins are released. In the production of black teas the halting of oxidization by heating is carried out simultaneously with drying.
Tea contains catechins, a type of antioxidant. The antioxidant content, measured by the lag time for oxidation of cholesterol, is improved by the cold water steeping of varieties of tea.
Tea contains L-theanine, a stimulant caffeine at about 3% of its dry weight.
Tea contains small amounts of theobromine and theophylline.
Although tea contains various types of polyphenols and tannin, it does not contain tannic acid.
Source of the image is here.
