The chemical composition of a freshly plucked tea shoots is as under:
Compounds |
% (on dry weight basis) |
Total Polyphenols | 25 – 30 |
Flavanols- | |
(-) Epigallocatechin gallate | 8 – 12 |
(-) Epicatechin gallate | 3 – 6 |
(-) Epigallo catechin | 3 – 6 |
(-) Epicatechin | 1 – 3 |
(+) Catechin | 1 – 2 |
(+) Gallocatechin | 3 – 4 |
Flavonols and flavonol glycosides | 3 – 4 |
Leuco anthocyanins | 2 – 3 |
Polyphenolic acids and depsides | 3 – 4 |
Caffeine | 3 – 4 |
Theobromine | 0.2 |
Theophyllin | 0.2 |
Amino acids | 4- 5 |
Organic acids | 0.5 – 0.6 |
Monosaccharides | 4 – 5 |
Polysaccharides | 14 – 22 |
Cellulose and Hemicellulose | 4 – 7 |
Pectins | 5 -6 |
Lignin | 5- 6 |
Protein | 14 - 17 |
Lipids | 3 - 5 |
Chlorophylls and other pigments | 0.5 – 0.6 |
Ash (minerals) | 5 - 6 |
Volatiles | 0.01 – 0.02 |
Of these chemical compounds, polyphenols contribute towards the astringency, while caffeine is responsible for the briskness of the tea liquor. Volatiles present in tea leaf contribute to the aroma and chlorophylls and other pigments are responsible for colour and appearance of tea.