Abstract
Theaflavin (TF) and thearubigin (TR) have generally been known as the colored components in the black tea infusion. Particularly, thearubigin deepens the color in the infusion but its chemical structure is yet unknown.
The teas are known to be better in quality when their color is bright reddish, and a considerable amount of chlorophylls has been detected from the dry leaves of Darjeeling black tea of higher grades whose flavor is excellent.
From the results of experiments on the correlation between the period of fermentation of black tea and the chlorophylls content in the dry leaves, the flavor was proved to be excellent when the period of fermentation was relatively shorter, whereas the color was deep reddish when the period of fermentation was relatively longer.
It was recognized that chlorophylls were decomposed in proportion to an increase of fermentation periods, and that the color of black tea became more deep when the fermentation lasted for a period of two hours.
Also, High Speed Liquid Chromatography was to be effective procedure to identify of chlorophylls and its related in the tea leaves.
