The purpose of the master's thesis was to determinate the microbiological quality of raw milk from 50 different vending machines in Slovenia. Instrumental analyses were used to determinate the basic chemical composition and hygienic quality of raw milk samples. We used the traditional method of growing microorganisms on petri dishes to determinate the presence of the total number of microorganisms, lactic acid bacteria, enterobacteria, staphylococci, Salmonella and Listeria monocytogenes. We used the MALDI – TOF MS method for the identification of microorganisms to determinate their genera and species. The total number of microorganisms ranged from 9,0 x 103 to 3,5 x 108 CFU/mL. The dominant genera presented were Pseudomonas (23,5 %), Acinetobacter (14,7 %) and Lactoccocus (6,5 %). Less than a quarter of the samples met the requirements which state that raw milk samples should not contain more than 100.000 CFU/mL. The average number of lactic acid bacteria was 3,8 x 105 CFU/mL. The largest percentage of the total population of samples was represented by the genera Lactobacillus (34,4 %), Lactococcus (23,5 %) and Leuconostoc (15,6 %). The presence of samples of enterobacteria in raw milk was on average 2,1 x 105 CFU/mL. The genera Hafnia (31,0 %), Citrobacter (17,3 %) and Enterobacter (14,2 %) were dominant. Only one sample reached a value below 10 CFU/mL, which is the limit for the presence of enterobacteria in raw milk. The samples contained on average 7,1 x 102 CFU staphylococci/mL. None of the samples was positive for Salmonella and three samples were positive for Listeria. Two were of the species Listeria monocytogenes and one of Listeria innocua.
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