Abstract
Water absorption and softening characteristics of dried tomatoes during soaking was measured at five temperatures ranging from 30 to 70°C. The moisture content data were fitted to an exponential model in the decreasing period using a non-linear least squares method. The measured results agreed well with the empirical results. An Arrhenius type equation was used to relate the constant k for water absorption rate to temperature. A first-order rate equation was applied to the change of surface softening for the sample during soaking. As a result, an Arrhenius relationship can be derived between the constant ks for softening rate and water temperature. The activation energy for softening was estimated and the relationship between softening and pectin diffusion were described. Therefore, it was found that changes in surface softening associated with water absorption during soaking affect the water absorption characteristics of dried tomato material.
