Survival of S. cerevisiae present in a mixed culture, inoculated on the surface of various films and on the cheese surface in the case of DA and stored at 7 ± 1 C, is shown in Fig. 3. Microbial analysis for Port Salut cheese (with and without film) is presented in Fig. 3a. A cheese without inoculum and without film (CH) and an inoculated cheese without film (ICH), were also evaluated for comparison purposes. The inoculated cheese without film (ICH) showed an initial yeast count of 4 log CFU/ml, increasing 3 log cycles in 196 h. The CH showed yeast counts below 10 CFU/ml until 144 h of storage; from that time and on, the yeast reassumed the growth achieving at the end of storage a value of 4 log CFU/ml, trend that revealed the presence of native flora. Covered cheeses with films CF and CNANI showed a yeast count similar to cheese CH, indicating that these films did not allow the passage of contaminant yeast. However they did not exert any antimicrobial effect on native yeast present in cheese evaluated. The cheese covered with film NANI (containing both antimicrobials) presented a count lower than 10 CFU/ml throughout the trial, without allowing the growth of
native yeasts. Instead, the cheese with the direct application of antimicrobials (DA) produced a 1 log cycle reduction of yeast counts the first 24 h but immediately reassumed growth reaching a value of 5 log CFU/ml at the end of the storage.