Abstract:

In this paper, the effects of various dehumidification and modeling temperatures during the shaping process on the quality of famous keemun black tea were studied. The dehumidification process were arranged for four different temperatures as 100℃ by hot air dryer baking, high (180±5)℃, middle (160±5)℃and low temperature (140±5)℃ by electric roast frying, combining with three different modeling temperatures as high (120±5)℃, middle (100±5)℃and low (80±5)℃respectively. According to the tea sensory test and the main biochemical compositions analyses, the results showed that different dehumidification temperatures led to significantly effect on color of soup and infused leaves of tea, and extremely significant effect on the contents of thearubigins (TR) and theabrownines (TB). Different modeling temperatures didn’t have significant effect on sensory qualities and biochemical ingredients of tea. Tea quality of the process of baking was equal to the process of roasting, its efficiency was significantly higher than that of roasting, and the middle modeling temperature was fit for tea shaping within baking and roasting. It was better to shape by middle dehumidification and modeling temperature of roasting for tea quality rather than low temperature. It was liable to over-fired in the process of roasting with the high temperature. The optimum temperature combinations were as follows: 100℃ by hot air dryer baking or (160±5)℃ by electric roast frying dehumidify, and (100±5)℃ for tea modeling.