The analytical modelling of a food freezing process is a very complex task, due mainly to the change of phase that is involved. Besides the large difference in the values of the foods density, thermal conductivity and heat capacity between frozen and non-frozen states, the use of an analytical solution is always influenced by the lack of reliability of the values used for these thermal parameters, and also by the uncertainty in measuring h, the heat transfer coefficient between food and freezant, since it will very much depend on several geometrical characteristics of the specific equipment: racks form and position, air profile, position of the food pieces in relation to each other, etc.