Abstract: Supersonic technology assisted water extraction to extract polysaccharides from leaves of Vaccinium uliginosum L. was researched in this experiment. The factors of ultrasonic time, ultrasonic power,extracting time and water temperature were studied. Through a comparison analysis and L9(34) orthogonal design, ultrasonic time, ultrasonic power, extracting time with water and water temperature were investigated respectively. The results indicated that the most significant factor was the extraction temperature, then the ultrasonic time, ultrasonic power and time of water diffusion. The optimal conditions in the extraction procession were as follow: ultrasonic time 15 min , ultrasonic power 200 W, water diffusion time 75 min and water temperature 90 ℃. On the optimal conditions the extracting rate of polysaccharides could reach 7.96%. The total extraction time is only 90 min. Compared with the traditional technology, it reduces the time of extract process and energy consumption significantly.

Key words: supersonic, Vaccinium uliginosum L., polysaccharide, orthogonal test