Effects of Heating Condition (Hiire) on the Qualities of Green Tea

Abstract

The effects of heating conditions (hiire) on the qualities of greentea were investigated employing a laboratory hot air oven of which air was capable to circulate. As the results of sensory test, it was found that the heated tea produced the most favorable aroma when it was heated at 90-100°C for 30 minutes or at 110°C for 20 minutes. The desirable moisture contents for storage i.e. 3-4% was obtained by heating at the best conditions above mentioned. In this case the loss of ascorbic acid and conversion of chlorophyll to pheophythin in tea was not remarkable. From the results of gas chromatographic analysis, it seemed that the heated favorable aroma appeared in the range from 80 to 110°C of heating temperature.