Abstract: Temperature is the most significant parameter in the drying process of Xiangcha, a kind of green tea. In this study, tea samples were prepared at various drying temperatures (90, 110, 130 and 150 ℃). During the drying process, changes in moisture content and leaf temperature were monitored continuously. Energy consumption and flavor composition were analyzed at the end of drying. The results indicated that drying temperature differently influenced the drying efficiency, energy consumption and aroma composition of tea. Higher drying temperature accelerated the rate of water loss and the highest drying efficiency was obtained at a drying temperature of 150 ℃. Both excessively high (150 ℃) and excessively low (90 ℃) drying temperature were not beneficial for energy saving. The lowest energy consumption was found upon drying at 130 ℃, which was reduced by approximately 1/4 when compared with those at 150 and 90 ℃. The amount of total aroma components in tea dried at higher temperature (150 and 130 ℃) was significantly higher than in tea dried at lower temperature (110 and 90 ℃) (P < 0.05). The contents of linalool with floral and citrus-like aroma, geraniol with floral and rosy aroma, phenylacetaldehyde with floral and chocolate-like aroma, and furfural with baked aroma were 35%, 20%, 64% and 36% higher at 150 ℃ than at 90 ℃, respectively. On the basis of the best compromise among drying efficiency, energy consumption and flavor quality, the optimal drying temperature was 130 ℃.

Key words: drying; temperature; moisture content; energy consumption; aroma components; flavor