Tea is the agricultural
product of the leaves, leaf buds, and internodes of
the Camellia sinensis plant, prepared and cured by
various methods. "Tea" also refers to the aromatic
beverage prepared from the cured leaves by combination
with hot or boiling water, and is the common name for
the Camellia sinensis plant itself.
After water, tea is the most widely consumed beverage
in the world. It has a cooling, slightly bitter,
astringent flavour which many enjoy.
There are at least six varieties of tea: white,
yellow, green, oolong, black and pu-erh of which the
most commonly found on the market are white, green,
oolong and black. All teas are made from the same
species of plant, though different varieties may be
used, and the leaves are processed differently, and,
in the case of fine white tea, grown differently.
Pu-erh tea, a post-fermented tea, is also often used
The term "herbal tea" usually refers to an infusion or
tisane of leaves, flowers, fruit, herbs or other plant
material that contains no Camellia sinensis. The term
"red tea" refers to an infusion made from either black
tea (mainly in Chinese, Korean, Japanese and other
East Asian languages) or the South African rooibos
plant (containing no Camellia sinensis).
Green tea is tea made
solely with the leaves of Camellia sinensis that have
undergone minimal oxidation during processing. Green
tea originates from China and has become associated
with many cultures in Asia from Japan to the Middle
East. Recently, it has become more widespread in the
West, where black tea is traditionally consumed. Many
varieties of green tea have been created in countries
where it is grown. These varieties can differ
substantially due to variable growing conditions,
processing, and harvesting time.
Over the last few decades green tea has been subjected
to many scientific and medical studies to determine
the extent of its long-purported health benefits, with
some evidence suggesting that regular green tea
drinkers have lower chances of heart disease and
developing certain types of cancer. Although there
is no scientific evidence that plain green tea can
produce weight loss, a green tea extract rich in
polyphenols and caffeine has been shown to be useful
for "obesity management", since it induces
thermogenesis and stimulates fat oxidation.