The rehydration of the freeze-dried fruits involved a high water uptake rate at the early stage of the process followed by a decreased rate and finally approaching saturation condition. Mango, papaya and pineapple presented the higher rehydration rates as compared to acerola and guava, which, on the other hand, had higher rehydration ratio at the saturation. A discrimination of the three models fitted to the experimental data indicated theWeibull equation as the most suitable to describe the rehydration behaviour of all freeze-dried fruits investigated in
this work, since it presented best statistical indicators. Furthermore,analysis of Weibull equation parameters provided useful information on comparison of rehydration kinetics of the freezedried fruits, allowing an in-depth understanding of the process. Analysis of the index, which takes into account both the fluxes of water uptake and leaching of solubles responsible for mass gain,indicated that acerola and guava had the higher abilities to rehydrate
among the freeze-dried fruits. The elevated loss of solutes observed in pineapple, mango and papaya was the main reason for their low restoration ability. The comparison between the high porosities of freeze-dried materials and their corresponding abilities to restore water lost
during drying revealed that care must be taken when using rehydration characteristics as indicative of structural damage incurred upon drying. From analysis of the WAC values, glass
transition temperatures of the freeze-dried fruits and water bath temperature, it was presumed that structural changes induced by rehydration itself have a great influence on the capacity of materials to imbibe water and fully rehydrate. The decreased porosity of acerola due to structural collapse during rehydration was a reasonable explanation for the lower rehydration capacity and rate presented by the most porous freeze-dried fruit. Material Tg andwater bath temperature,whichdefine the extent of interaction between the porous matrix and the reconstitution medium should, therefore, be considered for optimizing the rehydration conditions in order to preserve the quality of the final product.