Finite element modelling of food cooking

Abstract

In the last few years there has been an evident rise in the production of previously cooked, ready-to-serve meals. At a global level, the studies on this matter have yet to develop. Heat (and mass) transfer are modelled to predict thermal histories, microorganisms destruction and, finally, the cooking time. Both the experimental and modelling problems are quite complex, due to an important contribution of the radiation in the oven to the heat transfer and the simultaneous water loss by means of evaporation, porosity and volume variation, crust formation, etc. Nowadays the modelling of the process is carried out using finite differences or finite elements, contemplating important simplifications. To simulate the cooking of different foods in a convection oven, a commercial finite elements software (ALGOR) is used. The three-dimensional mesh of finite elements is formed using “Brick” elements, proper of the ALGOR software heat transfer module. The thermal variable properties of the food are considered, including the specific apparent heat, which involves the evaporation of water in the superficial crust. The convective and radiation components of the heat transfer in the air-food system are also taken into account. This is done with heat transfer coefficients determined in specific experiments for the utilized oven. The obtained results are validated against experimental data, from cooking runs of the same foods in the determined oven.