## 3 Results
### Microbial Purity Analysis  
It was shown that the number of mesophilic bacteria found in the sliced cooked ham kept in the non-active coating bags (C--control sample) increased markedly after 48 h (\(p<0.001\)) and 96 h (\(p<0.0001\)) of storage at 5 \({}^{\circ}\)C in air conditions (than when placed in comparison to sample \"0\"--pre-storage). Figure 4 shows that a Ut coating containing 5% of the _U. tometosa_ extract and decreased amount of ZnO nanoparticles had an impact on the increase in mesophilic bacterial cells. It decreased the number of living cells after 48 h of storage compared to the samples, which were stored in bags devoid of coatings. Additionally, a higher than 1 log increase in bacteria number was seen (compared to sample \"0\"--pre-storage) for the slices stored 48 h in bags covered with the Ut coating. Unfortunately, the Pb coating did not decrease the number of microorganisms compared to the \"0\" sample and to the samples stored in bags without any coatings. It would be too easy to advance that only the coating with Ut extract was able to be active against mesophilic bacteria and that Ut active layer was significantly more effective than the Pb layer. As emphasized below (Figure 2), the PP films coated with the Ut layer had a significant influence on the total count compared to the PP bags covered with the Pb coatings and to the number of mesophilic microorganisms detected from the samples stored in the bags devoid of active coatings after storage of 96 h. There was clear evidence that the number of bacterial cells in the case of sliced ham samples stored in PP bags and in PP bags that were coated with the active layers was higher (than compared to the \"0\" sample--pre-storage) after 96 h storage. A clear statistical analysis showed that any variances between the number of microorganisms stored for 96 h were found to be significant (\(p<0.0001\)). From the point of view of microbiological analysis, a limit that would be acceptable for a total viable count of products such as sliced meat is 6-7 log\({}_{10}\) CFU/g [27]. Nevertheless, it is of note that according to [PERSON] et al. [28], a microbial load lower than 3 log\({}_{10}\) CFU/g is a satisfactory/acceptable number of mesophilic bacteria for products made up of sliced meat, and the 4 log\({}_{10}\) CFU/g is generally accepted as a maximum total count that would be seen as acceptable for sliced ready-to-eat meat products. A higher number of bacteria than 4 log\({}_{10}\) CFU/g is seen as an unacceptable microbial load in the case of consumable sliced cooked ham. This means that all samples stored in PP bags that did not contain active layers or in active bags that were fully covered with the Ut or Pb active coatings were not suitable to be consumed after 48 and 96 h of storage (Figure 4). It has to be underlined that two bars of cooked ham had the same expiration date (\(\pm 2\) days) on the day when  
Figure 3: (**a**) The uncoated PP film. (**b**) The PP film covered with the Zn coating. (**c**) The PP film covered with the Ut coating. (**d**) The PP film covered with the Pb coating. they were purchased. Additionally, the ham was sliced by the shop assistant, who could contaminate the samples during slicing. It can be mentioned that the producer suggested the ham consumption within 2-3 days after the package opening. The results confirmed that the sliced ham was not acceptable for consumption after 48 h of their storage, but a lower increase in mesophilic microorganisms was noted for the samples stored in bags coated with the Ut layer. These findings suggest that the package covered with the more effective coating could decrease the number of bacteria to an acceptable level. The results of the study confirmed that Ut and Fb coatings inhibited the growth of _S. aureus_, _B. atrophaeus_, and _E. coli_ strains (Table 1) and decreased the number of _P. syringae_ cells (Figure 2). According to [PERSON] et al. (2018), the number of coliform bacteria found in 10 mg of sliced cooked ham has to be zero. In contrast, the number of cells of _S.