Microbiology of “Orinotyri”, a eweʹs milk cheese from the Greek mountains Original Research Article

The microflora of five batches of Orinotyri, a cheese made from raw eweʹs milk, was studied in ten day and three-month-old cheese. Mean log counts of 7·94 for Enterobacteriaceae and 7.41 for coliforms in fresh cheese were reduced (P<0·05) by 3·02 and 2·76 log units, respectively, during ripening. It also seems that high cheese pH (means: ten days, 6·31; three months, 5·79) did not favour the growth of yeasts. These organisms were found at low levels only in fresh cheese. Lactic acid bacteria numbers of the cheese at ten days decreased significantly (P<0·05) in the three-month-old cheese, but they were still present at high levels (mean log counts: lactobacilli, 5·78; lactococci, 8·24; enterococci, 6·20). Enterococci predominated in the fresh cheese, but they were outnumbered by lactococci in three-month-old cheese. Enterococcus faecalis and Lactococcus lactis subsp. lactis were the most frequently isolated species. Acid production by Lc. lactis subsp. lactis strains varied considerably and the same was observed for their caseinolytic, lipolytic and peptidolytic activities. The results suggest the possibility of choosing strains for industrial fermentation.