Simplified computational model of the primary and secondary freeze-drying process of agriculture and marine foods

The food freeze-drying is a low-pressure and low-temperature dehydration process during which the following basic steps can be distinguished: (1) freezing of the food product in the chamber, (2) vacuuming of the freezing chamber, (3) ice sublimation from a frozen food product (primary drying), (4) removing the water bound in the food product (secondary drying). This paper discusses a simplified 1-D in-house computational model of the primary and secondary freeze-drying processes, i.e. stages 3 and 4. In particular, it allows for times prognosis of both, primary and secondary freeze-dryings separately. Finally, that analysis provided the basis for the proper selection of the thermal parameters in the process. Complex analysis of the drying process can also result in the reduction of energy consumption. In this project the experimental campaign together with computer simulations has been performed for various food products including meat, fruit and vegetables.