K. DINKOV, M. DUSHKOVA and N. TOSHKOV
University of Food Technologies, Department of Process Engineering, BG - 4002 Plovdiv, Bulgaria
DINKOV, K., M. DUSHKOVA and N. TOSHKOV, 2008. Regression models for density and viscosity of ultrafiltration milk concentrates. Bulg. J. Agric. Sci., 14: 542-548
Ultrafiltration of skim and standardized milk was carried out with a UF25-PAN polyacrylnitrilic membrane with 25 kDa molecular weight cut-off at volume reduction factors VRF=2, VRF=3, VRF=4 and VRF=5. The density and viscosity values of the initial milks and the ultrafiltration milk concentrates obtained from them were experimentally established. Mathematical models for the dependence of density and viscosity on the combined influence of the dry matter and temperature of ultrafiltration concentrates from skim and standardized milk were obtained. The results demonstrated an increase in the ultrafiltration concentrate density of 1.03 times for skim milk and 1.04 times for standardized milk under volume reduction factor variation from two to five, and an increase in ultrafiltration concentrate viscosity of 2.6 times for skim milk and 2.8 times for standardized milk under volume reduction factor variation from two to five.