INFLUENCE OF MELAMINE AND UREA ON MILK QUALITY INDICATORS

Abstract

The addition of melamine and urea to milk helps to increase the protein content, which is one of the main criteria for evaluating its quality. This is due to the fact that the determination of protein is directly related to its calculation by the non-protein and protein nitrogen determined by the Kjedal method, and melamine and urea contain nitrogen molecules in their composition. An interesting question is the effect of these adulterating components on milk quality indicators. The main method for determining these indicators is ultrasonic, implemented using milk analyzers. However, they do not provide for the determination of melamine and urea, which are determined by high-performance liquid chromatography and colorimetric methods, respectively. Therefore, it is not possible to detect the adulteration of milk with melamine and urea using ultrasonic analyzers. The aim of the work was to determine the effect of melamine and urea when added to milk quality indicators determined using an ultrasonic analyzer "Lactane 1-4". The work was carried out in stages on the basis of the educational and research center for the examination of food and animal Feed of the St. Petersburg State University of Veterinary Medicine. The objects for research were samples of raw milk with different concentrations of melamine and urea. Thus, the dependence of milk quality indicators on the concentration of urea and melamine in it has been established. At the same time, it was found that the higher the concentration of these substances in milk, the higher the value of its indicators such as mass fractions of protein, fat and density.