Abstract:

Ultrasound can be divided into low frequency ultrasound and high frequency ultrasound. High frequency
ultrasound, which is different from low frequency ultrasound in terms of cavitation efficiency, can produce a large amount of
free radicals, and it has a good efficiency in degradation and modification and great application potential in the food industry.
However, there are rarely systematic summaries of its application in this area. This article briefly illustrates the mechanism
of action of ultrasound, and reviews the application of high frequency ultrasound in molecular degradation and modification.
High frequency ultrasound can not only degrade macromolecules, but also can modify some of their groups and properties.
Herein we also summarize the mechanism of the degradation and modification of polymer molecules in order to provide a
theoretical basis for the application of high frequency ultrasound for degradation and modification of polymers.

Key words: high frequency ultrasound, degradation, modification, cavitation, free radicals