Tea; Camellia sinensis
Tea is the most important & a popular non-alcoholic drinks in the world. The word of tea was originated from “kia” in Chinese & then was evolved into "cha" in the 6th century A.D. Then this term became té upon its arrival in the West, which is still been used in many countries (with spelling difference).
Tea plant is usually small with a height of 50-200 cm but cultivated plants are kept pruned to a normal human’s reachable height. Its leaves are glossy green & 5-13 cm in length. Tea plants can yield for about 25-50 years.
Tea is prepared from leaves, leaf buds & tender stalks of different varieties of camellia sinensis. The 4 most important classes (based on types of processing) are:
1. Black tea (leaves - fermented).
2. Green tea (leaves - unfermented, rapidly steamed).
3. Oolong tea (leaves - partially fermented).
4. White tea (the most delicate of all teas. The new leaf buds are plucked, withered slowly at low temperatures).
The caffeine is a natural component of tea leaves. The alkaloids, caffeine & oils give the characteristic flavour of tea.
Health & Medical Benefits:
Tea leaves contain chemical compounds called polyphenols. The caffeine extracted from tea is added to some pain-killer medicines. Tea also has fluoride (which is vital for teeth) & has no calories. Recent research shows that any tea derived from camellia sinensis has cancer-fighting properties.
Polyphenols in tea have been known to:
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Besides polyphenols, tea also contains theanine (an amino acid, unique to tea), vitamins [vitamin A, B, C, D, E & K (specifically green tea)], minerals & methylxanthines. These components are vital in:
- fighting against mutagenic agents.
- delaying aging process.
- fighting high blood pressure.
- combating against viral & bacterial infection.
- improving the functions of the digestive & excretory systems.
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