Microbiological, physicochemical, and biochemical changes during ripening of camembert cheese made of pasteurized cow's milk

Camembert cheese was manufactured from pasteurized cow's milk by the traditional method in order to determine changes in the microflora, physicochemical, and biochemical characteristics over a 30-day ripening period. The total bacteria counts were high in cheese throughout ripening, with lactic acid bacteria being the main microbial group both on the surface and the center of the curd. However, the microbial activity was more important on the surface than in the center. Each group of microrganisms showed a typical variation during ripening on the surface and in the center. External heterogeneous microflora containing yeasts, molds and halophilic bacteria induced a higher rate of proteolysis and lipolysis on the surface than in the curd of the cheese at the end of ripening (30 days). Migration of salt from the curd reached equilibration after 23 days of ripening. A fast increase in the pH of the surface was observed and the pH differential was maintained between the surface and the center during the ripening period. Rheological analysis demonstrated the softening of Camembert cheese during ripening due to extensive proteolysis.