Processes of contaminant transfer into foods by diffusion-convection or by diffusion from packaging made of a recycled layer and a functional barrier

Reusing old plastics as food packaging necessitates the presence of a functional barrier (made of a virgin polymer) between the food and old plastics. The transfer of the potent contaminant through the packaging is controlled by diffusion, leaving aside of the transfer of the food into the packaging. Depending on whether the food is liquid or solid, the process of transfer of the contaminant in the food is controlled either by convection, with a coefficient of convective transfer in the food, or by diffusion. The two processes have been studied in detail and the results are expressed in terms of master curves. Some emphasis is put on the effect of the value of the diffusivity in the food and of the coefficient of mass transfer on the contaminant transfer into the food.