Microbiological quality assessment of raw milk from a vending machine and of traditional Slovakian pasta filata cheeses

摘要

Culture-based microbiological assessment of raw milk from a vending machine and of traditional Slovakian pasta filata cheeses made from raw milk was performed in this study. Unsatisfactory hygienic conditions of raw milk were indicated by the average counts of coliform bacteria and E. coli at a level of 3.00 ± 0.26 log CFU·ml~(-1) and 1.94 ± 0.56 log CFU·ml~(-1), respectively. Similarly, higher counts of coliforms at a level of 3.74 ± 1.20 log CFU·g~(-1) on average were determined in pasta filata cheeses. The presumptive numbers of coagulase-positive staphylococci in raw milk were under the limit that is crucial for enterotoxins production. However, in pasta filata cheeses, the EU limit of 4 log CFU·g~(-1) for coagulase-positive staphylococci was exceeded in 53.8 % of samples. Counts of microscopic fungi in raw milk ranged from 2 log CFU·ml~(-1) to 4 log CFU·ml~(-1) and Geotrichum candidum was detected in 86.7 % of raw milk samples. The average counts of microscopic fungi in pasta filata cheeses were 3.85 ± 1.39 log CFU·g~(-1). Despite the pasta filata cheese manufacture includes heat treatment (60-80 °C), the results of this study point to the need to pasteurize raw milk not only before consumption but also prior to production of Slovakian artisanal pasta filata cheeses.