Heat Transfer in the Cooling, Freezing and Post-Freezing of Liquid Food: Modeling and Simulation

In pursuit of greater practicality in the food preparation, in recent years there has been a considerable growth of researches in the field of cooling and freezing of food. Therefore, the trade in frozen food has been very promising, allowing a great variety of products to the consumers due to the convenience of transportation, storage and use. Cooling and freezing of products are preservation methods used in the food industry to maintain the sensorial attributes and nutritional properties of these products. In this sense, in order to optimize the process and reduce energy costs, this work presents a transient three-dimensional mathematical modeling to describe the heat transfer inside liquid materials with parallelepiped shape including phase change (liquid-solid) term. The governing equation was solved numerically using the finite volume technique with a fully implicit formulation. As an application, the methodology was used to predict heat transfer during cooling, freezing and post-freezing of the Tahiti lemon pulp. Numerical results of the temperature distribution at different process instants are presented and analyzed, and temperature data at the center of the product throughout time were compared to experimental data reported in the literature and a good agreement was obtained.