The oxidation products such as theaflvins and therubigins contribute to tea color and taste of the black tea. Tea is the product of its environment; how the tea is grown and how it is processed. These variables make each tea unique and give it body, character, aroma (and health properties).
The flavor of tea is principally determined by the chemical components it contains. Volatile compounds contribute to the aroma and non-volatile compounds to the taste.
The principal components which determine the aroma, flavor and physiological action of tea are:
*An essential oil: about 0.5%, this is probably formed during fermentation.
*Caffeine: 1.8 to 5.9%. Caffeine (1, 3, 7-trimethylxanthine) is one of the major alkaloids in tea.
*Flavonoids, which were previously called tea tannins or tea polyphenols, are the main phenolic compounds comprising 20–40% of dry matter in young shoots of tea plants. The characteristics of made tea, including colour, taste, and aroma, are directly or indirectly associated with these phenolic compounds.
There are about 140 components have been reported as contributing to the aroma and flavor of tea. Chlorophyll, carotenoids, lipids and volatile compounds are not major constituents in a tea brew but they also play an important role in the development of the aroma.
The odor of the tea liquor, also called the nose or fragrance. A complex aroma is often described as a bouquet.
Caffeine together with black tea polyphenols was necessary for the expression of reasonable amounts of tangy astringency. Astringency is a lively and mouth-drying effect on the tongue. The sensation of astringency is caused by a reaction between polyphenols (tannins) and the protein in saliva. Decaffeination may change the nature of astringency from tangy to non-tangy type.
The chemical composition of tea depends on the following factors: genetic strain, climatic conditions, soil, growth altitude and horticultural practices, the plucking season, sorting (grading) of the leaves, the processing, storage, etc.
The aim of making good tea is to obtain the maximum extraction of caffeine. Most commercially available teas are blends, designed to satisfy the tastes of the customer.
Taste of tea
