Heat transfer study and modeling during Emmental ripening Original Research Article

Firstly, thermal properties were determined on various Emmental cheese samples in order to check the literature empirical relationships for dairy products. Thermal conductivity or diffusivity values were in good agreement with the predicted data considering the temperature effect and the cheese composition in terms of water, fat and non-fat concentrations. Furthermore, the external convective heat transfer coefficients values were experimentally determined by using the psychrometric method with different air flow patterns similar to industrial round cheese ripening conditions. These coefficients are globally higher than published data concerning heat exchange between air and cylindrical bodies. For a temperature change step from 5 to 16 °C applied in our ripening cellar, the experimental temperature profiles measured in the round cheese were in good agreement with the data predicted by numerical simulation by using a 2-D finite difference method. For the temperature step higher than 16 °C, the model could be improved by taking into account the endothermic source terms corresponding probably to melting enthalpies of cheese fat fractions.