Use of Ultrasound Pretreatment in Drying of Fruits: Drying Rates, Quality Attributes, and Shelf Life Extension

Evolving advanced pretreatment techniques such as application of ultrasound prior to fruit drying have attracted significant research and development efforts due to the rising demand for high-quality dried fruits at reduced operating costs. Drying processes can be destructive to the quality of fruits due to long drying times and high temperatures in some cases. The effects of ultrasound pretreatment on quality aspects of dried fruits and on drying kinetics are reviewed. Ultrasound is known for its varying effects on different fruits; however, it has been proved to greatly increase drying rates and hence reduce the overall processing time. Ultrasound pretreatment in distilled water as the media is an interesting concept when low-calorie dried fruits are required.