Effect of ultrasonic treatment on structure and physicochemical properties of starch: An updated review

This review systematically summarizes the effects of ultrasound on the multi-scale structure and physicochemical properties of starch. Ultrasonic treatment can affect the fine structure, short-range and long-range ordered structures and granule structure of starch through mechanical forces, cavitation effects and accompanying thermal effects. These structure alterations collectively lead to significant changes in starch hydration behavior, pasting viscosity, thermal properties, rheological characteristics and in vitro digestibility. The extent of these effects is highly dependent on ultrasonic parameters including ultrasonic power, treatment time and temperature, as well as the combination of ultrasound with other modification methods (such as microwave processing, pullulanase treatment and alkaline modification). However, the lack of standardized ultrasonic parameters setting has limited the ability to obtain consistent and comparable conclusions. Therefore, the concept of "equivalent cavitation dose (ECD)" was innovatively introduced in this review, which was a quantitative framework integrating ultrasonic power, duty cycle, treatment duration, system temperature and medium physicochemical properties. This concept provides a reference for parameters standardization setting to achieve a more in-depth comparison among different studies. Overall, this review provides a theoretical basis for optimizing ultrasonic modification of starch, guiding the development of starch with tailored structures and functionalities to expand its application in the starch industry.