EVALUATION OF PHYSICO-CHEMICAL INDICATORS AND FRACTIONAL COMPOSITION OF SHEEP AND COW WHEY PROTEINS FOR THE PRODUCTION OF SOFT CHEESE

Abstract

As a result of the research, it was established that sheep and cow milk serums are characterized by a clean taste and smell characteristic of milk whey, without extraneous flavors and odors, a straw-yellow color, a homogeneous consistency with the presence of a slight protein precipitate. When studying the physical and chemical properties of serum from sheep's and cow's milk, probable differences were established regarding the amount of nitrogenous substances, the content of dry substances, lactose and indicators of titrated acidity. A significant difference was found in the amount of nitrogenous substances. In sheep serum, this indicator was 40.87% (p < 0.05) higher than in cow serum. A significantly (p < 0.01) lower mass fraction of dry substances in cow serum was also found. The average mass fraction of lactose was 4.59±0.32% in cow serum and 4.28±0.23% in sheep serum, i.e. in sheep serum it was 7.2% lower than in cow serum. During electrophoresis of sheep and cow milk serum, the following fractions of serum proteins were isolated: fast fraction, β-lactoglobulin 1, β-lactoglobulin 2, after β-lactoglobulin, albumin, after albumin 1, after albumin 2, after albumin 3, proteozo- peptone, immunoglobulins and starting fraction. During the electrophoretic separation of serum proteins, we established differences in the values of protein fractions of sheep and cow serums. The analysis of the research results showed differences in the fractional composition of the studied sheep and cow sera. In particular, whey from cow's milk was characterized by a significantly (p<0.05) lower content of the fast fraction compared to sheep serum, respectively 5.57% versus 15.85%. The mass fraction of β-lactoglobulin and albumin was higher in cow serum, where it was 11.15±1.23% (β-lactoglobulin 1), 23.46±1.96% (β-lactoglobulin 2), and 15 .31±0.91% (albumin).