Osmosonication for dehydration of fruits and vegetables: Mechanistic understanding, mathematical models and comprehensive applications in processing

Background: Over several decades, osmotic dehydration has been used extensively to dehydrate fruits and vegetables. However, it is a time consuming process and leads to poor rehydration ability along with loss of nutrients. To overcome these shortcomings, ultrasound waves are integrated with osmotic dehydration, a process referred to as osmosonication. It is a non-thermal, energy efficient, promising technology with enormous potential to prolong shelf life while maintaining nutritional characteristics. Scope and approach: Extensive work has been done on osmosonication in the last decade. The objective of this review is to provide a complete paradigm on osmosonication by discussing its working mechanisms and applications for various types of fruits and vegetables. Additionally, its effect on mass transfer kinetics, physicochemical, nutritional and structural properties of individual fruits and vegetables have been discussed. This review also covers the empirical and mathematical models applied during dehydration, factors affecting osmosonication, and its advantages and disadvantages. Key findings and conclusions: Osmosonication leads to the formation of microchannels in the food matrix, improving the mass transfer rate and reducing drying time. Fruits and vegetables like kiwi, strawberry, apple, plum, potato, aonla and mushroom pretreated with osmosonication were found to have an improved nutritional profile, enhanced physicochemical properties and better overall quality of the final food product, along with improved mass transfer characteristics. Additionally, osmosonication has also assisted in achieving improved retention of bioactive compounds, refined colourimetric results, a good rehydration ratio and a fair weight reduction in the final product. Moreover, osmosonication increased dry matter content, reduced titratable acidity and lowered hardness in the final product, leading to better sensory properties compared to osmotically dehydrated fruits.