Interaction of milk fat solidification and cheese cooling

In this paper, we report on the interaction between cooling and fat crystallization, that happens during the processing of mozzarella cheese. The analysis is performed using a novel physical model in which the Fourier equation is extended with a source term representing the latent heat released by fat solidification. The kinetics of fat solidification follow a model originally developed for chocolate, which we have modified for milk fat, using input from our Differential Scanning Calorimeter (DSC) measurements of Mozzarella cheese samples. The model parameter estimation was conducted using a structured parameter estimation method involving the Fisher Information Matrix. The DSC analysis, and simulations, supplemented by mathematical scaling analysis, clearly show that a significant amount of latent heat is released, affecting the total cooling time and cooling rate. The interaction between cooling rate and crystallization is also bidirectional, as the cooling rate determines the types and amounts of fat crystal polymorphs formed.