Inactivation of microbiota and selected spoilage and pathogenic bacteria in milk by combinations of ultrasound, hydrogen peroxide, and active lactoperoxidase system

Ultrasound has the potential for numerous applications in the dairy industry, as it is possible to inactivate microorganisms while causing minimal changes to the natural properties of milk. This study evaluated the inactivation of microbiota and selected spoilage and pathogenic bacteria in milk using combinations of ultrasound and hydrogen peroxide (H2O2) or the active lactoperoxidase system (LP-s). The effect of ultrasound alone or in combination with H2O2 or sodium thiocyanate (NaSCN):H2O2 ratio (LP-s) was influenced by amplitude, sonication time, type of microorganism and concentration of H2O2 or NaSCN:H2O2 ratio (LP-s). Sonication in the presence of H2O2 or the active LP-s was more effective as higher microbial reduction was obtained at lower amplitude and shorter treatment time compared with sonication alone. These results suggest that ultrasound combined with H2O2 or the active LP-s has a potential to ensure the microbial quality and safety of milk.