OSMOTIC DEHYDRATION IN FRUIT AND VEGETABLE PROCESSING

The basic principles which control osmotic dehydration of fruit and vegetables are reported together with the most important parameters and their influence on the process. The effects of osmosis as a pre-treatment, mainly related to the improvement of nutritional, sensorial and functional properties of the products, are analyzed. The distinctive aspect of this process, when compared to other dehydration methods, is the 'direct formulation' achievable through the selective incorporation of solutes, without modifying the food integrity. By balancing the two main osmotic effects, water loss and soluble solids uptake, the functional properties of fruit and vegetables could be adapted to many different food systems. Present applications of the process are shown and problems related to a further industrial development are analyzed.