Study of the kinetics of vacuum drying of hard and semi-hard cheeses

The research considers cheeses as an object of drying process. It describes the changes occurring in the cheese during the drying process. The description of cheeses by their organoleptic, physicochemical and thermal-physical indicators is given. The results of experimental studies of cheese vacuum drying are presented as well; in particular, there are some diagrams of changes in the heat flux density, temperature and relative mass of cheeses. The kinetics of cheese vacuum drying is investigated. Such important indicator as the shrinkage losses of cheeses in the process of vacuum drying was studied. It has been established that cheese vacuum drying proceeds in two steps: at constant drying speed and at falling one. The drying curves of various types of cheeses were obtained and investigated in the coordinates (heat load — time, temperature — time, moisture mass fraction — time). By graphic differentiation, the curves of the speed of cheese drying were constructed. It was determined by an analytical method that the moisture content of polymolecular adsorption for cheeses is 4–9%. The temperature curves in the coordinates (temperature - moisture mass fraction) were investigated.