Preliminary characterization of microflora of Comte cheese

摘要

The evolution of the microflora of three Comte cheeses made in duplicate with raw milk from three different sources was followed during ripening. The same starter was used with each type of milk. The comparison of the cheeses did not reveal any significant difference in the development of the microflora. Starter lactic acid bacteria (Streptococcus thermophilus and Lactobacillus helveticus), which are added at the beginning of manufacture, decreased quickly in the first stages of ripening supporting the hypothesis of cell autolysis. Other microorganisms, i.e. homofermentative and heterofermentative lactobacilli (Lact. delbrueckii ssp, lactis, Lact. paracasei ssp. paracasei, Lact. rhamnosus and Lact. fermentum), pediococci, enterococci and propionibacteria grew in cheese from small numbers in fresh curd. The characterization of Strep. thermophilus by pulsed-field gel electrophoresis showed that wild strains were also able to grow in the curd. The values for the genome size of 11 Strep. thermophilus strains determined in this investigation were in the range of 1.8-2.3 Mbp. The potential role of starter and raw milk microflora in cheese flavour development was considered.