Improving the quality of raw milk and yogurt

Abstract

Milk is a part of many food products. In the expert assessment of the quality of raw materials, primary attention should be paid to its microbiological safety, since poisoning with dairy products is a common cause of diseases of the gastrointestinal tract. The experiment has been carried out on the base in the Teaching and Production Livestock Farm in the Federal State Budgetary Educational Institution of Higher Education “Russian State Agrarian University – Moscow Agricultural Academy named after K. A. Timiryazev” (Moscow). The purpose of the research was to improve the quality indicators of raw milk and yogurt. The method of processing raw milk, which reduces the number of potentially dangerous microorganisms in the products produced from it, has been studied. During the experiment the influence of electromagnetic radiation on organoleptic and physic and chemical parameters has been observed; the quantitative and qualitative composition of milk and yogurt microorganisms has been evaluated. The samples of raw materials had a uniform consistency without sediment and flakes, the color was milky white, and the smell was characteristic of natural cow’s milk. Electromagnetic treatment did not affect the main elements of the chemical composition of milk: the mass fraction of dry substances, fat, protein and lactose. In the experimental samples of raw milk after electromagnetic pulses treatment, the decrease in the growth rate of microorganisms including Quantity of Mesophilic Aerobic and Facultative Anaerobic Microorganisms (QMAFAnM), yeast and mold, has been noted. No bacteria of the Staphylococcus aureus and Escherichia coligroups have been found in the milk samples. The electromagnetic field had the negligible effect on the amount of lactic acid microorganisms in the raw material. During the experiment, there was no negative influence of electromagnetic radiation on the organoleptic, physic and chemical and sanitary-hygienic parameters of yogurt. The issues of ensuring the microbiological safety of raw milk have been described and the method for optimizing the sanitary and hygienic parameters of yogurt in accordance with the current requirements of regulatory documents has been suggest in the article.