EFFICACY OF ANTIMICROBIALS IN FERMENTED MILK STORAGE

The existing methods of disinfection of containers for fermented milk products proved to be ineffective. The present research featured an antimicrobial preparation based on silver, copper, and zinc nanoparticles as a disinfectant solution. The authors studied the properties of the antimicrobial in order to prove its effectiveness in processing containers to increase the shelf-life of fermented milk products. The size of the silver nanoparticles ranged from 1 to 10 nm. The nanoscale particles of copper were obtained by the method of electric explosion. It was established that the mass fraction of the active substance (active metals) in the antimicrobial was 50.1%; the mass fraction of water was 11.2%; the mass fraction of hydrogen peroxide was 1.0%. To assess the ability of the antimicrobial to increase shelf-life of fermented milk products, the authors analyzed the microbiological properties of cottage cheese. The 50-gram samples were packed in pre-treated polyethylene containers that had been cleaned with the antimicrobial. After that the samples were left for storage at minus 4 ± 1°C. The quality and the microbiological state of the cottage cheese was evaluated on days 3, 5, 7, 9, 11, and 13, which was justified by the experimental conditions and regulatory documentation. Eventually, it was established that the product contained no pathogenic bacteria, such as L. monocytogenes, Salmonella, E. coli, staphylococci, yeast, molds or any viable microbial cells. It was proved that the test sample retained its consumer properties for 13 days, while the control sample was found unusable by day 7. Thus, by using the antimicrobial, it was possible to increase the shelf life of the dairy product by more than 5 days.