Antimicrobial packaging efficiency of ZnO-SiO2 nanocomposites infused into PVA/CS film for enhancing the shelf life of food products

In the current work, antimicrobial bionanocomposite films were fabricated based on chitosan (CS), poly (vinyl alcohol) (PVA) and nanocomposites comprised of silicon dioxide nanoparticles doped with zinc oxide nanoparticles (ZnO-SiO2). The ZnO-SiO2 nanocomposite was prepared and incorporated into a PVA/CS blend at different ratios (0.50, 1.0, 3.0 and 5.0 %) to generate the PVA/CS/ZnO-SiO2 bionanocomposites. The prepared ZnO-SiO2 nanocomposites as well as the PVA/CS/ZnO-SiO2 bionanocomposite films were evaluated using SEM, FT-IR, XRD and determination of the final contact angle. Furthermore, the mechanical properties, gas permeability (GTR) and water vapor transmission rate (WVTR) of the prepared PVA/CS/ZnO-SiO2 bionanocomposite films were evaluated. The fabricated bionanocomposite films displayed superior antibacterial activity against Gram-positive bacteria (staphylococcus aureus, S33R) as well as Gram-negative bacteria (Escherichia coli, IRAQ 3). Correspondingly, the prepared PVA/CS/ZnO-SiO2 bionanocomposites were used for bread packaging. The obtained result revealed the greatly improved visual appearance of the bread that was packaged in the PVA/CS/ZnO-SiO2 bionanocomposite film. Moreover, the totality of these various observations and testing methods led to an increase in the shelf life and reduced the amounts of food-borne pathogens in the packaged bread. This PVA/CS/ZnO-SiO2 bionanocomposite film is an antimicrobial packaging material that may reduce the current negative environmental footprint of packaging materials.