Abstract: This project involves the preparation of ultramicro green tea powder and green tea extract(instant tea powder)from low medium grade fresh tea leaves using microwave fixation, ultrasound-assisted extraction, microwave freeze drying under vacuum with new instruments, and experimentation on the tea quality effects of different fixation, extraction and drying methods using various experimental parameters.The results were obtained through physical determination, sensory eva luation, instrumental analysis and chemical experimentation. Using new drum-type microwave fixation at 8KW of the irradiation power within 50s and new drying technology for the preparation of ultromicro green tea powder, the color, smell and taste were all good, and the re-hydration quality of products was improved .Apart from that, the drying time of the new technology was one fourth of the heated-air drying’s; By using new microwave vacuum freezing drying technology, first of all, the drying time was immensely reduced; Secondly, the low-temperature solubility of the products became much better in comparison with conventional methods; Lastly, the quality of the prodcuts was enhanced since more nutrition was retained in the product through freezing drying. This project also involves the pilot tests of preparation of green tea powder and green tea extrat(instant tea powder) using new technology.
Keywords：Ultramicro green tea powder, Green tea extract, Microwave, Ultrasound
