Identification of yeast species involved in fermentation of the Kazakh camel dairy product–shubat
¹ITMO University, Department of Applied Biotechnology, Lomonosov street 9, RU191002 Saint Petersburg, Russian Federation
²The Russian Academy of Agricultural Sciences, The Saint Petersburg Branch State Research Institute of a Baking Industry, Podbelsky Chaussee 7, RU196608 Saint Petersburg, Pushkin, Russian Federation
³All-Russia Research Institute for Agriculture Microbiology, Laboratory of Genetics of Plant-Microbe Interactions, Podbelsky Chaussee 3, RU196608 Saint Petersburg, Pushkin, Russian Federation
⁴Harbin Institute of Technology, Institute of Food Science and Engineering, School of Chemistry Engineering, Xidazhi street 92, CN150001, Harbin, Heilongjiang, P.R. China
*Correspondence: l_tochka@corp.ifmo.ru, orazov@corp.ifmo.ru
Abstract:
In certain countries of the world, camel’s milk is used for food on a level with cow’s milk. Shubat is a traditional food product based on camel milk in Kazakhstan. It is a fermented milk product obtained as a result of spontaneous fermentation of camel’s milk under the influence of native microflora. Received dairy product from the southern region of Kazakhstan became the object of the investigation of the microflora of the fermented milk product shubat. The aim of the research was to study the microflora of camel milk, which causes its spontaneous fermentation. During the experiment, the dynamics of acid accumulation by the change in active acidity (pH) and titratable acidity (°T) was studied. In addition to lactic fermentation fermented product (shubat), alcoholic fermentation was noted, which has given the finished product an increased acidity and a high degree of gassing. To enumerate and identify microorganisms, shubat was sown to the following nutrient media: MRS, Malt wort-agar medium at 36 °C and 30 °C respectively both for 3 days. We suppose that the dominant component of the shubat’s microflora was yeasts: Brettanomyces anomalus, Naumovozyma castellii. Pathogenic microorganisms, such as Salmonella, Shigella, were not detected during the research, considering that the shubat is formed as a result of spontaneous fermentation and has poor hygienic characteristics in comparison with pasteurized milk. Identification of individual strains of bacteria allows us to simulate a starter microflora for the production of a safe fermented product based on camel milk on an industrial scale in Kazakhstan. The identified microflora, which causes spontaneous fermentation of camel milk and isolated strains of lactic acid bacteria, will make a significant contribution to the improvement of food safety in arid regions.
Key words:
Brettanomyces anomalus, camel milk, lactic acid bacteria, Naumovozyma castellii, shubat, spontaneously fermented dairy products, yeasts