Rehydration kinetics of dehydrated products

The rehydration kinetics of various dehydrated fruits and vegetables (apple, potato, carrot, banana, pepper, garlic, mushroom, onion, leek, pea, corn, pumpkin, and tomato) were examined during rehydration at different temperatures. Dehydrated products were produced in an air dryer at 70 degreesC and 10% air humidity, and subsequently they were rehydrated in a bath of water tempered at 40, 60 and 80 degreesC. A first order kinetic model was used, in which the rate constant and the equilibrium moisture content are functions of the process variable (water temperature). The parameters of the model considered were found to be greatly affected by the water temperature during rehydration. In particular the temperature increment increases the rate of rehydration and the equilibrium moisture content of the rehydrated products. (C) 2002 Elsevier Science Ltd. All rights reserved.