The modelling of heat transfer within materials with high porosity is complicated by the evaporation-condensation phenomenon. The aim of this work is to develop a model of apparent thermal conductivity in these products. The effective thermal conductivity of a porous food model (sponge) having 0-60% moisture content and 0.92-0.94 porosity was measured by a line-source heat probe system in the range -35-25degreesC. Two predictive models of the effective thermal conductivity of porous food were developed (Krischer and Maxwell models). The effective thermal conductivity predicted by the Krischer model was in good agreement with the experimental data. Also, it was shown that the model, including the effect of the evaporation-condensation phenomenon in addition to heat conduction, was useful in predicting the effective thermal conductivity of foodstuffs.