Comparative study of various drying processes at physical and chemical properties of strawberries (Fragariavarcamarosa)

The objective of this work was to study and compare different drying processes of strawberry. The impact of DIC as texturing process within a swell drying operation was quantified when inserted before the second stage of hot air drying (swell drying SD). The obtained results showed that DIC treatment has a great impact on drying kinetics and performances compared to those of classical hot air drying. The drying of DIC-textured strawberry was accelerated even under low temperature (soft conditions). That can be explained by the direct impact of swelling on diffusivity and starting accessibility. Indeed, the mechanical effect of pressure drop leads to a great expansion of the structure, while the short thermal treatment time can preserve the quality. Thus, the new modified texture makes the trapped water accessible for improving the diffusion especially in the second stage of drying after the shrinkage of product, as well as in the rehydration process; the water holding capacity can be much higher. So the necessary time to reach the optimum final water content for the storage is shorter in case of DIC-swell dried strawberry compared to the classical hot air dried products. (C) 2012 Published by Elsevier Ltd.