Effect of high pressure on mikroflora of kefir

Abstract The aim of the studies was the effect of high pressure (200–800 MPa for 15 min.) on microflora of kefir. The number of streptococci, lactobacilli and yeasts was determined before and after pressure treatment and after 1, 2 and 3 weeks of storage at a temperature 4°C and 20°C. A considerable reduction of the number of streptococci, being 39%, lactobacilli-45%, and completely inactivation of yeasts was found in kefir, subjected to the pressure of 400 MPa. As affected by the pressure of 800 MPa, the complete inactivation of acidifying bacteria was not found. The pulsatory pressurization of kefir caused higher inactivation of microflora The decrease of the number of acidifying bacteria was observed during 1, 2 weeks storage of pressurized kefir, a small increase of bacterial count was found but not exceed, the number of lactic bacteria directly after pressurization. the acidity increased only slightly.