An Introductory Review of Applications of Ultrasound in Food Drying Processes

Abstract

In this study, applications of ultrasound in food drying processes have been reviewed. High frequency ultrasonic treatment can be used in food drying processes as a pretreatment or for the improvement of the main process and the traditional driers. Ultrasonic waves at low frequency can also be used as a diagnostic method for measuring properties of the final dried products and controlling the drying process. Ultrasonic pretreatment has direct and indirect applications. Ultrasonic direct pretreatment improves drying processes by intensifying heat and mass transfer. Indirect implementations of this technology involve the ultrasonic waves as parts of drying systems such as nozzles of spray-driers or freezing sections in freeze-drying systems.