Microbiological research aspects of cottage cheese, obtained by the use of ultrafiltration while producing and storing

For the majority of Russian population, cottage cheese can be regarded as a daily product. The subjects of research are CWP-UV (concentrated whey proteins-ultrafiltration) samples of cottage cheese obtained with the use of membrane methods of whey treatment. In the article a brief description of cottage cheese production technology and the results of research are given. Microbiological aspects of cottage cheese obtained with the technique of ultrafiltration usage while producing and storing in different packages, in two different storage conditions are considered. It is shown, that the membrane technique based on the use of modern filtration methods allows developing dairy products with corrected medical and dietary composition. Microorganisms identification up to biologic species by the means of microscopic examination is carried out. Morphological and cultural characteristic features on the basis of results obtained from generally accepted biochemical tests are described. It is shown that there are following lactic streptococcus prevailing in cottage cheese composition: Str. lactis, Str. cremoris, Str. thermophilus, Str. citrovorus. They make up 54-60 % from the total amount of lactic microorganisms. Lactobacillus L. acidophilus and L. thermophiIus are also observed. As for the presence of yeasts and mold fungi vegetative cells and opportunistic microflora, freshly produced cottage cheese is considered to be of high quality. No pathogenic or opportunistic microorganisms are detected in the storage process, but the growth and development of mold fungi and yeast are observed. Storage temperature is one of the most important factors, influencing accumulation of these microorganisms. The results of completed microbiological researches of storage cottage cheese are