Formulation of a 3D conjugated multiphase transport model to predict drying process behavior of irregular-shaped vegetables

In this paper, a conjugated multiphase transport model aimed at predicting the behavior of food convective drying was formulated. The model referred to a 3D spatial domain in which two samples were exposed to drying air, flowing around the foods. The system of non-linear, unsteady-state, partial differential equations modeling the simultaneous transfer of momentum, heat and mass, occurring in both the drying chamber and the food samples, was solved by a finite elements formulation. The present study was intended to cover missing aspects in scientific literature dealing with food drying modeling. It represents, in fact, one of the first attempts to rigorously describe, for given process operating conditions, the transport phenomena involved during drying process of irregular-shaped vegetables, considered as multiphase hygroscopic porous media with different characteristics. In addition, one of the major contributions offered by this work regarded the possibility of identifying, on food samples surfaces, the points where the local values of both water activity and temperature might determine an inefficient or, even, an unsatisfactory abatement of microbial population, thus causing microbial spoilage.