Rehydration of dried fruit pieces in aqueous sugar solutions: a review on mass transfer and final product characteristics

The results from different papers on the rehydration of air-dried and freeze-dried fruit pieces in aqueous sugar solutions are reviewed. The effects of the extrinsic rehydration variables on the mass transfer between fruit and solution and on the physico-chemical characteristics of the rehydrated products are also reported and discussed. By varying the concentration of solutions used as rehydration medium and the nature of the solute, it is possible to adjust the water and soluble solid transfer in order to obtain products with the desired water activity, freezing point, freezable water content and firmness. Rehydration in aqueous sugar solution could thus improve the stability, technological functionality and sensory quality of fruit pieces used as an ingredient in food to be consumed at room, chilling or sub-freezing temperatures