Drying processes, which have a great significance in the food industry, are frequently based on the use of thermal energy. Nevertheless,
such methods may produce structural changes in the products. Consequently, a great emphasis is presently given to novel treatments
where the quality will be preserved. Such is the case of the application of high-power ultrasound which represents an emergent and promising
technology. During the last few years, we have been involved in the development of an ultrasonic dehydration process, based on the
application of the ultrasonic vibration in direct contact with the product. Such a process has been the object of a detailed study at laboratory
stage on the influence of the different parameters involved. This paper deals with the development and testing of a prototype
system for the application and evaluation of the process at a pre-industrial stage. Such prototype is based on a high-power rectangular
plate transducer, working at a frequency of 20 kHz, with a power capacity of about 100 W. In order to study mechanical and thermal
effects, the system is provided with a series of sensors which permit monitoring the parameters of the process. Specific software has also
been developed to facilitate data collection and analysis. The system has been tested with vegetable samples.
2006 Elsevier B.V. All rights reserved.