Formation of Antimicrobial Packaging Biopolymer Nanocomposite Materials for Food Storage

Film nanocomposite packaging materials based on polylactide-polyhydroxybutyrate (PLA-PCL) biopolymers in a ratio of 80:20 wt.% were formed by spraying Ag nanoparticles on the surface of the polymer matrix. Using the method of wide-angle X-ray scattering, it was established that the investigated PLA-PCL biopolymers are characterized by a semi-crystalline structure, and the presence of metallic silver particles on their surface was confirmed. Analysis of the morphology of the studied systems showed that a layer of silver nanoparticles with a thickness of $\sim 425 \mathrm{~nm}$ is formed on the surface of the polymer matrix (sputtering time 5 min). It was established that the spraying of silver nanoparticles on the surface of PLA-PCL polymer mixtures leads to a decrease in the temperature at which the thermal destruction of the polymer matrix begins. The data of differential scanning calorimetry show that in PLA-PCL mixtures, taken in a ratio of 80:20, the effect of PCL is manifested in the action on the crystallization and melting of polylactide. It was found that PLA-PCL-Ag samples with silver nanoparticles sprayed for 3 and 5 minutes showed antimicrobial effects against S. aureus and E. coli. The PLA-PCL-Ag packaging materials have suppressed the number of mesophilic aerobic and facultative anaerobic microorganisms during poultry meat storage compared to conventional vacuum film and PLA-PCL film.