Analysis of Shrinkage Phenomena in the Process of Cheese Vacuum Drying

Abstract

The work is devoted to the study of the shrinkage phenomena during the vacuum dehydration of the cheese varieties “Sovetskiy” and “Gollandskiy”. During the research, the dependences of the cheese shrinkage coefficient on the initial mass fraction of moisture were obtained. It was found that when the mass fraction of the cheese moisture increases, an increase in the shrinkage coefficient of the product occurs. The greatest increase in the cheese shrinkage coefficient is observed when the mass fraction of moisture is more than 50%. It was established that with increasing temperature and heat load, the moisture content on the cheese surface rapidly decreases, while in the central layers it changes more slowly. Shrinkage at elevated temperatures is less; however, dry cheese has a large mass fraction of moisture. It was found that an increase in the difference in the mass fraction of moisture between the inner and surface layers is accompanied by an increase in the difference between the actual shrinkage and possible shrinkage corresponding to the amount of liquid removed. The coefficients of shrinkage in the volume of the “Sovetskiy” and “Gollandskiy” cheese varieties were calculated: they lie in the range of 0.017–0.004 and 0.006–0.003, respectively. The dependences of the cheese shrinkage coefficients on the drying layer thickness, shape and size of grinding were obtained. Keywords: cheeses, vacuum drying, shrinkage