APPLICATION OF PHENOMENOLOGICAL MATHEMATICAL MODEL FOR ANALYSIS AND SIMULATION OF FISHBURGUER FREEZING

Freezing is a unit operation widely applied as a conservation method of meat products, as fishburguer. It’s possible from experimental freezing curves and from application of mathematical models on these curves understand the freezing behavior of foods and optimize the process. The aim of this work was to perform theoretical study and computational modeling of the cooling and freezing process of the tilapia's fishburger from computational code on Maple®13 language. The experiments were conducted on conventional freezer with fast freeze function (H500, Electrolux). From experimental freezing curves were obtained parameters as freezing rate, air temperature inside the freezer and temperature in the fishburger's center measured by thermocouples of T type (Novus). It was evaluated a mathematical model of distributed parameters, considering the fishburguer as a physical system that transfer heat by conduction and natural convection, beside uniform cooling and one-dimensional heat transfer. The physical properties were estimated from models which consider the composition of the product. The numerical method selected to solve the mathematical model was the line method of lines. This method consisted in transforming the partial differential equation to a set of ordinary differential equations which were solved by an algorithm develop in Maple®13. From the resolution of these equations, it was possible to simulate the temperature behavior as a function of fishburguer freezing time. The simulated curves that better fit the experimental curves and that showed the highest coefficient of determination (0.98) were obtained using convective coefficient of 12.6 W m-2 K-1. These results showed that the proposed phenomenological mathematical model fitted to the experimental data, so it simulated the tilapia's fishburguer freezing profile until the formation phase of ice crystals.