Saturday, May 23, 2009

Chemical Composition of Tea Flush

Chemical Composition of Tea Flush
Tea flush is generally a reference to young shoots of tea that consist of tea that consists of the terminal bud and two adjacent leaves.

In fresh tea flush there exist a wide variety of non-volatile compounds: polyphenols, flavonols and flavonol glycosides, flavones, phenolic acids and depsides, amino acids, chlorophyll and other pigments, carbohydrates, organic acid, caffeine and other alkaloids, minerals, vitamins and enzymes.

The chemical composition of the tea leaves depends upon leaf age, the clone being examined, soil and climate conditions and agronomic practices.

Tea total polyphenols in tea flush ranges form 20% to 35%. Tea polyphenols include mainly mainly six groups of compounds.

Among them, the flavonols (mainly the catechins) are the most important group and occupy 60- 80% of the total amount of polyphenols.

The catechins have been widely and intensively investigated for their bioactivity and utilization.

Four major catechins, namely epigallocatechin-3-gallate, epigallocatechins, epicatechins-3-gallate and epicatechins, constitute around 90% of the total catechins fraction and catechins and gallocatechin are present about 6% of the total fraction.

There are some minor catechins that constitute less than 2% of the total catechins.

The catechins that are water-soluble, colorless compound contribute to astringency and bitterness in green tea.
Chemical Composition of Tea Flush

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