Synonym: Camellia thea

Biological source: It contains the prepared leaves and leaf buds of Thea sinensis

Family: Theaceae

Geographical source: India, Sri Lanka, China, Indonesia arid japan. It is available as black tea from India and Sri Lanka and green tea from China and japan.

Collection and Preparation

• Small evergreen shrub 1.0 - 1.5 metres.

• Black tea is obtained by fermenting the heap of fresh tea leaves and further drying with artificial heat

• Green tea is obtained by putting tea leaves in copper pans and then drying by artificial heat.

Macroscopic characters Leaves:

Colour: Dark green,

Odour: Characteristics

Taste: Bitter

Shape: Lanceolate or elliptical glabrous.

Margin and Apex: Blunt at apex serrate margin

Flowers are solitary or in groups of 2 or 3 in the leaf axils, and drooping.

Preparation of Green Tea

• It is prepared by exposing the freshly collected leaves to the air until most of the moisture is removed.

• Then they are roasted and stirred continuously until leaves become moist and flaccid.

• Then they are passed to rolling table and rolled into balls and subjected to a pressure which removes the moisture.

• Then the leaves are shaken out on the copper pans and roasted again till the leaves assume dull green colour.

• Then the leaves are winnowed, screened and graded into various varieties. 3

Chemical constituents:

• Rich source of caffeine (1 - 3%)

• Theobromine and theophylline

• Colour of tea leaves is due to gallotannic acid (15%)

• The agreeable odour is due to presence of a yellow volatile oil.

• An enzymatic mixture called thease.

Uses:

• • • • CNS stimulant

      • In beverage

      • As diuretic