摘要
How to quickly and economically dry materials to obtain high-quality products is the core problem that needs to be solved by drying field. At present, traditional simplex drying technology fails to meet the actual demands in some aspects. Exploring the combination of various drying technologies has become a hotspot of research in recent years. Power ultrasound (sound intensity lager than 1 W/cm2) is a green and pollution free processing method. It has shown its unique superiorities in the aspects of strengthening heat transfer and mass transfer of water content during drying. Therefore, power ultrasound is with wide application prospect in the field of food drying. This paper mainly introduced the recent progress of ultrasonic drying techniques in the aspects of ultrasonic pretreatment before food drying, ultrasonic enhancement of osmotic dehydration, ultrasonic coupling hot air drying, ultrasonic coupling spray drying, ultrasonic coupling freeze drying, ultrasonic coupling heat-pump drying and ultrasonic coupling solar drying, etc. And this paper also analyzed the effects and mechanisms of action, summarized the advantages of ultrasound drying, and pointed out the existing problems and future research directions.
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