Effect of Tannase-treatment on the Creaming of Black Tea Infusion

Abstract

Effects of concentration, pH-value, caffeine content and temperature of tea infusion on the degree of creaming (turbidity) were examined quantitatively.
As it was observed that creaming was markedly decreased when a tea infusion was incubated with tannase, effect of tannase-treatment on the creaming of infusion was examined in detail under various conditions.
It was found that decrease of turbidity was in close connection with liberation of gallic acid from polyphenols, and the infusion (1.8g/100ml, 4ml) which was incubated previously with 100 units of tannase (1ml) for 1hr at 50°C was scarcely turbid by cooling at 2°C.