Abstract: To explore the appropriate drying technology during raw tea processing, leaching behaviors and quality stabilities of tea samples prepared from raw materials dried by different methods or degree of drying were compared. The results revealed that (1) Raw tea dried by frying showed the highest contents of tea polyphenols when processed under low temperature, whereas those dried by baking-frying, or baking-frying-backing showed the highest contents of tea polyphenols when processed under high temperature. (2) In respect of color stability, tea soup prepared from baking-dried tea showed significantly elevated L value after sterilization or during storage, with the average L value increased by 2.035-3.905. Meanwhile tea soup prepared from baking-dried tea also showed higher anti-discoloration, with a/b value during low-temperature storage increased by 19.5%. (3) In respect to sensory flavor, most tea soups showed yellow-green color and ripe aroma while tea samples processed by baking-drying remained green, bright and fresh without any ripe taste. Besides, tea samples processed by baking-drying also showed superior flavor stability during storage irrespective of temperatures. In conclusion, baking approach during raw tea process was proposed with the optimized drying content between 5%-6%.

Key words: raw materials, drying technology, flavor, tea beverage