MICROBIOLOGICAL STUDY OF TRADITIONAL CHEESE PRODUCED IN RUGOVA REGION OF KOSOVO

Rreze Gecaj, Kemajl Kurteshi, Idriz Vehapi, Muharrem Ismajli, Matthias A. Ehrmann, Flutura C. Ajazi, Bajram Berisha

Abstract: Total mesophilic bacteria, anaerobic bacteria, lactic acid bacteria, enterobacteria as well as yeast and moulds were investigated during the production of the traditional Rugova cheese without using any starter culture. This type of cheese has been produced and consumed by the local population in the Rugova region for centuries, and is important for their economy. Samples from different stages of production (raw milk, curd and cheese during maturation on day 1, 8 and 14) were collected from local farms in the Rugova region, Kosovo, during winter. After sample collection and their serial dilution, samples were plate on different media and incubated at the appropriate temperature. According to identical morphology and physiology the number of 52 isolates obtained from de Man, Rogosa, and Shape (MRS), and M17 agar was reduced to ten Gram-positive and catalase negative strains. These strains were subjected to API 50 CHL fermentation profiling. There was a variety of microbial groups detected in all stages of cheese production, with the dominant microbial groups being Lactococcus (from 6.44 log cfu/ml in milk to 8.39 log cfu/gr in cheese D14) and Lactobacillus (from 5.79 log cfu/ml in milk to 7.58 log cfu/gr in cheese D14). Enterobacter and yeast and moulds were found in lower amounts compared to the other microbes in all stages. The level of Leuconostoc was approximately the same as Lactobacillus. Almost all microbial groups were low in curd and started to increase from day one of cheese manufacturing. Three of the ten isolates were identified as Lactococcus lactis ssp. lactis, four as Lactobacillus plantarum (2 isolates) and L. curvatus (2 isolates). One isolate of each of Lactobacillus paracasei ssp. paracasei, L. brevis and L. pentosus were identified. These results confi rm the competitiveness of high numbers of LAB during fermentation of this cheese.

Keywords: LAB; microbial activity; Rugova region; traditional cheese

Date published: 2019-04-09