## 4 Conclusions  
The green synthesis method of silver NPs using beetroot juice as reducing and capping agents has been proposed and implemented for the production of silver-enriched antimicrobial recyclable free-standing films for their possible application in food packaging. In order to obtain free-standing films, a mixture of fresh beetroot juice and gelatin-water solution with a certain amount of admixed AgNO\({}_{3}\) was prepared and exposed to UV light.  
It was shown that, at low concentrations of 1M AgNO\({}_{3}\) (10-30 \(\mu\)L), clusters of small Ag seeds were produced. At higher silver nitrate concentrations, a number of differently sized Ag nanoparticles were produced, and a particle growth tendency was observed. The produced particles were characterized through XRD as cubic phase metallic Ag particles. Due to the relatively low concentrations of AgNO\({}_{3}\) in the initial beetroot-gelatin mixture, the number of the produced particles was modest, but they were well dispersed in the whole film volume, thus indicating the antimicrobial effectiveness of the produced films. It was shown that the antimicrobial effectiveness was dependent on the pH of the solution. The best antimicrobial effectiveness was achieved at pH = 3 and pH = 4 in the case of _E. coli_ as well as at pH = 7 and pH = 8 in the case of _C. parapsilosis_ and _A. fumigatus_.  
Conceptualization, J.P. and D.A.; methodology, J.P.; investigation, J.P., A.P., D.A. and A.V.; writing--original draft preparation, J.P.; writing--review and editing, J.P. and D.A. All authors have read and agreed to the published version of the manuscript.  
This research received no external funding.  
\begin{table}
\begin{tabular}{l l l l l l l l} \hline \hline \multirow{2}{*}{**Microorganism**} & \multirow{2}{*}{**pH**} & \multirow{2}{*}{**Control (Beetroot juice)**} & \multicolumn{2}{c}{**BuAg10 UV**} & \multicolumn{2}{c}{**BuAg20 UV**} & \multicolumn{2}{c}{**BuAg30 UV**} & \multicolumn{2}{c}{**BuAg40 UV**} & \multicolumn{2}{c}{**BuAg50 UV**} \\ \cline{3-8}  & & & \multicolumn{2}{c}{**Zone Size, mm**} & & & & \\ \hline \multirow{4}{*}{_Pseudomonas aeruginosa_} & 3 & 0 & 0 & 0 & 0 & 0 & 0 \\ \cline{2-8}  & 4 & 0 & 5.0 \(\pm\) 0 & 5.0 \(\pm\) 0 & 5.0 \(\pm\) 0 & 5.0 \(\pm\) 0 & 5.0 \(\pm\) 0 \\ \cline{2-8}  & 7 & 0 & 12.0 \(\pm\) 0 & 13.5 \(\pm\) 0.5 & 15.0 \(\pm\) 0 & 15.5 \(\pm\) 0.5 & 12.0 \(\pm\) 0 \\ \cline{2-8}  & 8 & 0 & 13.0 \(\pm\) 0 & 8.5 \(\pm\) 0.5 & 10.5 \(\pm\) 0.5 & 15 \(\pm\) 0.5 & 13.0 \(\pm\) 0 \\ \hline \multirow{4}{*}{_Candida parapsilosis_} & 3 & 0 & 0 & 0 & 0 & 0 & 0 \\ \cline{2-8}  & 4 & 0 & 0 & 0 & 0 & 0 & 0 \\ \cline{2-8}  & 7 & 0 & 3.0 \(\pm\) 0 & 7.0 \(\pm\) 0 & 7.0 \(\pm\) 0 & 6.0 \(\pm\) 0 & 5.0 \(\pm\) 0 \\ \cline{2-8}  & 8 & 0 & 5.0 \(\pm\) 0 & 7.5 \(\pm\) 0.5 & 16.5 \(\pm\) 0.5 & 8.0 \(\pm\) 0 & 7.0 \(\pm\) 0 \\ \hline \multirow{4}{*}{_Varrowia lipolytica_} & 3 & 0 & 0 & 0 & 0 & 0 & 0 \\ \cline{2-8}  & 4 & 0 & 0 & 0 & 0 & 0 & 0 \\ \cline{2-8}  & 7 & 0 & 0 & 0 & 0 & 0 & 0 \\ \cline{2-8}  & 8 & 0 & 0 & 0 & 8.5 \(\pm\) 0.5 & 0 & 0 \\ \hline \multirow{4}{*}{_Aspgillus terreus_} & 3 & 0 & 0 & 0 & 0 & 0 & 0 \\ \cline{2-8}  & 4 & 0 & 0 & 0 & 0 & 0 & 0 \\ \cline{2-8}  & 7 & 0 & 0 & 0 & 10.5 \(\pm\) 0.5 & 0 & 0 \\ \cline{2-8}  & 8 & 0 & 0 & 0 & 12.0 \(\pm\) 0 & 0 & 0 \\ \hline \multirow{4}{*}{_Aspgillus fumigatus_} & 3 & 0 & 0 & 0 & 0 & 0 & 0 \\ \cline{2-8}  & 4 & 0 & 0 & 0 & 0 & 0 & 0 \\ \cline{2-8}  & 3 & 0 & 0 & 0 & 0 & 0 & 0 \\ \cline{2-8}  & 4 & 0 & 0 & 0 & 0 & 0 & 0 \\ \cline{2-8}  & 7 & 0 & 0 & 0 & 9.0 \(\pm\) 0 & 0 & 0 \\ \cline{2-8}  & 8 & 0 & 0 & 15.0 \(\pm\) 0 & 0 & 0 & 0 \\ \hline \hline \end{tabular}
\end{table}
Table 2: _Cont._  
**Institutional Review Board Statement:** Not applicable.  
**Informed Consent Statement:** Not applicable.  
**Data Availability Statement:** The data presented in this study are available on request from the corresponding author.  
**Conflicts of Interest:** The authors declare no conflict of interest.