EFFECTS OF HIGH-PRESSURE HOMOGENIZATION ON THE PHYSICOCHEMICAL PROPERTIES OF MILK WITH VARIOUS FAT CONCENTRATIONS

The effect of high-pressure (100 MPa) homogenization on some properties of the emulsion phase and colloidal phase of milk standardized to 2% fat or 4% fat were determined in the study. High-pressure homogenization caused a decrease in the size of fat globules and an increase in the level of protein compounds bound to the milk fat fraction, dependent upon the fat content of milk. The process resulted in an increase in the amount of ultracentrifuged sediment, in the level of sedimenting plasma proteins not bound to the milk fat fraction, and in the solubility of calcium salts and phosphorus salts, as well as a decrease in their levels in the colloidal form, related to the fat content of milk. High-pressure homogenization led to slight changes in active acidity and conductivity (increase), as well as to a substantial decrease in heat stability (max. 42.4%) and a shorter rennet coagulation time (max. 34.5%), directly proportional to fat concentration in milk.