Application of high-power ultrasound for dehydration of vegetables: Processes and devices

High-intensity ultrasound is a tool with a great potential for vegetable dehydration. Airborne ultrasonic waves have been used for drying materials in combination with hot air systems to obtain adequate drying rates at lower temperatures. Nevertheless, the extension of this technique has been limited because of practical difficulties in the efficient generation of high-intensity ultrasound in air. The implementation of a new technology of plate-transducer power ultrasonic generators has opened up new possibilities in this area. This article reviews the development and testing of an ultrasonic technology for vegetable dehydration based on the application of the new power ultrasound generators. Two experimental procedures have been carried out by airborne ultrasound and ultrasonic vibration in direct contact with the vegetable.