Abstract
The effect was investigated of the temperature of water on the foaming property of powdered green tea. Water temperatures of 20,40,60,70,80,90 and 100°C were tested to dissolve powdered green tea with subseqnent stirring of the tea solution. The foam volume, expansion rate and degree of stability of the foam were measured. The amounts of tannin, soluble nitrogen and pectin that could be dissolved at each of these temperatures in 30 seconds and the viscosity of the resulting tea solution werem also measured.
The higher the temperature of the water used to dissolve the powdered green tea, the more chemical elements were dissolved, the more the viscosity increased, the more the foam volume increased and the more the foam became fine and stable.
Evaporation at the surface of the foam membrane became more active, the foam disappeared more easily and the foam stability decreased as the temperature of the water during stirring was increased.
