Electromagnetic exposure effect on microbiological characteristics of raw milk
2018
Ananeva, T., Russian State Agrarian Univ. − Moscow Timiryazev Agricultural Academy (Russian Federation) | Ostroukhova, V., Russian State Agrarian Univ. − Moscow Timiryazev Agricultural Academy (Russian Federation) | Vasilyeva, E., Nizhny Novgorod State Univ. of Engineering and Economic, Knyaginino, Nizhny Novgorod Oblast (Russian Federation)
The increase of the sanitary and hygienic qualities of milk and dairy products demands working professionally on manufacturing technology and culture, improvement of equipment exploitation conditions and development of methods of influence on microbiological characteristics. A method of electromagnetic influence on the control system of a microbial cell is proposed, which allows reducing the degree of microorganisms development and improving the quality of milk, and, therefore, extending the expiration date of products. The object of the study was the milk of cows of the Kholmogory breed, which were kept using loose (group I) and tied (group II) housing system. It has been established that the method of keeping does not affect the physicochemical parameters, which meet the requirements for raw milk. The density, freezing point, acidity and somatic cells count were affected by the season. Changes in the quantitative composition of the sanitary-indicative microorganisms of raw milk depend both on the way the cows are kept and milked, and on the season. The highest bacterial contamination of milk was obtained for loose housing. The maximum quantity of microorganisms is observed in the summer for both methods of keeping. Salmonella were absent. Yeasts and moulds are registered in all milk samples. The influence of electromagnetic radiation on the development of individual microorganisms is registered. The largest quantity of mesophilic aerobic and facultative anaerobic microorganisms (QMAFAnM) was in raw milk without external influences with total number 486000 CFU•mlE-1. When exposed to electromagnetic pulses, the quantity of yeast and mould fungi decreased 9 or more times.
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