Modelling the thermal sterilisation of foods inside packs with two divisions Original Research Article

A mathematical model was developed to describe the heat transfer during the sterilisation of conduction heating foods inside three dimensional two division rectangular packs. The model uses a standard explicit finite differences method with non-capacitance surface nodes and simulates different pack sizes, food properties and surface heat transfer resistances at the package lid and walls. Taking into account the cooling phase, the sterility value was calculated as a function of position in order to identify the location of the least lethality point. The most important variables affecting the position of this point are the product heating rate and the surface heat transfer coefficients. For low heating rate values this critical point moves towards the surface. When different food products are sterilised in simultaneously the quality degradation of foods in this type of package is also a point of discussion.