In complex food system， bacteria may be protected or repaired by protein, fat and starch. In this research the protection effects of WPI on microbial inactivation under the ultrasound treatment was investigated using E. coli as target bacteria in order to expand the industrial application of ultrasound in food produciton. The results showed that WPI can protect the bacteria in the treatment of ultrasound with ultrasonic intensity (84 W/cm2) and treatment time (5 min). Under these ultrasonic radiation conditions, the higher the concentration of WPI, the stronger the effect of bacteria-protection. But under the treatment of ultrasound with intensity (105 W/cm2) and treatment time (15 min), the addition of WPI can promote the sterilization.
