2. Transient diffusion-controlled processes

This is undoubtedly the most widely explored area of internal transfer in thermal and process engineering. On the one hand, because the diffusion transfer partial differential equation has analytical solutions for different geometries and boundary conditions. Secondly, the transient diffusive transfer model has been shown to be sufficient to describe transfers within a solid in many industrial processes. For the food industry in particular, we can cite the following examples:

• drying: pasta, cereals ;

• pasteurization and sterilization of solid and liquid confined foods;

• solvent extraction of oil from soya beans or sunflower seeds, sucrose from sugar cane or beet, caffeine from coffee beans;

• brining, salting and ripening of cheeses and meats....