Modelagem e simulação da transferência de calor em alimentos com forma esferoidal prolata. Estudo de caso: resfriamento e congelamento de banana.

Abstract

Fruits are a type of food that are typically made by 80% to 90% water, making them extremely perishable. Thus, conservation methods should be applied to prolong their shelf life and consumer acceptance characteristics. This work aims to study the heat transfer during the cooling and freezing processes of fruits with a prolate spheroid shape. The mathematical modeling consisted of energy conservation equation written in spheroidal prolates coordinates. The numerical solution of the governing equation was performed using the finite volume method with a fully implicit formulation. The process was simulated by computer-based language within the Mathematica software, to obtain the temperature history at the center of the fruit and the temperature profile, the data being compared with experimental values of freezed banana prata, to obtain the transfer coefficient convective-heat and thermal conductivity of the fruit. We evaluated the influence of fruit dimensions of the cooling kinetics and the freezing fronts. It was found that the lower the product size, the faster the process, and the higher the aspect ratio of shape, higher will be the temperature gradient at the top of the product.