Theoretical moisture and temperature evolution during carrot slab drying were estimated with non-steady heat and mass transfer equations using constant and variable properties. Experimental drying kinetics of carrot slabs were obtained in order to compare with estimations. The results showed that moisture evolution, estimated for constant properties, reproduces approximately the experimental one, with deviations of experimental shape. Moisture evolution estimation for variable properties reproduces the experimental shape, but numerical effort is considerably increased. Temperature evolution is sensitive with respect to properties functions. This paper shows that constant properties assumption has application for engineering purposes and variable properties gives more phenomenological information for further predictions. (C) 2003 Elsevier Ltd. All rights reserved.