Estimation of the kinetic parameters of whey proteins proteolysis in the UF-concentrate of cheese whey

The purpose of the research is to substantiate the choice of enzyme preparations Promod 523MDP, Promod 439L, Flavorpro 766MDP, and Flavorpro 750MDP (Biocatalysts Limited, UK) and to determine the effective time of whey proteins hydrolysis in an ultrafiltration concentrate (UF-concentrate) of cheese whey for reducing their allergenicity based on the analysis of kinetic constants of the proteolysis reaction. Experimental studies were carried out with samples of cheese whey UF-concentrate with a total protein mass fraction at least 3.0% obtained with the use of industrial ultrafiltration unit MMS Swissflow UF with ceramic membranes under the conditions of the PSC Dairy Plant “Voronezhskii”. They were preliminarily subjected to enzymatic hydrolysis for 8 hours at a constant temperature, based on the dosage data, the optimum pH and the temperature of the used enzymes, recommended by the manufacturer. The specificity constant Vmax/Km was used to estimate the effectiveness of the enzyme preparations, which characterizes the constants of all stages of the hydrolysis reaction. The highest proteolysis rate has a mixture of Promod 439L and Flavorpro 766MDP in the ratio of 1.5 and 3.0%, respectively, of the total protein content in the substrate. Microscopy results showed an increasing in the solubility of nitrogen-containing components after hydrolysis due to a decreasing in hydrophobic areas on the surface of peptides. The resulting hydrolysate can be applied in the technology of a wide range of dairy products to reduce their residual antigenicity by partially replacing skim milk in the formulation.