Physicochemical, sanitary and safety indicators changes during the ripening of Bulgarian white brined cheese from local farms

Georgi Beev, Totyo Kolev, Nikolina Naydenova, Toncho Dinev, Milena Tzanova, Guyrga Mihaylova

Abstract: The present study aims to determine the physicochemical and microbiological changes of white-brined cheese from local farms during manufacturing and ripening. Milk pasteurization for white-brined cheese production leads to a severe reduction of microorganisms in milk. Thus, after pasteurization the total number of microorganisms decreases from 480 000 to 810 cfu/cm3, Salmonella spp. from 800 to 2 cfu/cm3 and E. coli from 4000 to 0 cfu/cm3. Ripening processes lead to a drastic reduction of cheese microflora with prevalence of specific lactic microflora (lactobacilli and lactococci) on the 45th day and complete annihilation of E. coli and Salmonella spp. These changes in the cheese microflora made the final product safe for consumption. On the other hand, the experimental data shows a strong multiplication of Salmonella spp. on the 7th day (10 cfu/cm3 at the 24th hour reached 0 cfu/cm3 on the 7th day) and insufficient decrease of the number of other microorganisms, making fresh white-brined cheese at its early ripening stages unsafe for consumption. Ripening of the cheese brings about an increase of the dry matter percentage (from 33.5% at 24th hour to 38.5% at 45th day), the fat content (from 13.3% to 16.4%), salt content (from 4.1% to 5.8%) and total protein content (from 13.7% to 16.7%) and reduction of moisture in non-fat substance (from 76.7% to 73.8%) of the final product. These changes are in accordance with the accepted standards for white-brined cheese production.

Keywords: microbiology; physicochemical properties; safety; white-brined cheese

Date published: 2019-12-30