Bioactive Nanocomposite Film Based on Cassava Starch/Polyvinyl Alcohol Containing Green Synthesized Silver Nanoparticles

The bioactive packaging polyvinyl alcohol PVA/starch (PSt) films were prepared by incorporating green synthesized silver nanoparticles (AgNPs). The effect of oregano essential oil (OEO) content on the green synthesis of AgNPs in PSt film was studied. The PSt-AgNPs containing 5 wt% OEO showed minimum inhibitory concentration againstEscherichia coli(E. coli) andStaphylococcus aureus(S. aureus). A synergistic effect on antibacterial activity with PSt incorporated AgNPs and OEO was achieved. The use of OEO content in this work was the lowest when compared to other bioactive containing OEO. The improvements of water resistance were also observed. The tensile strength and tensile modulus of film increased 80.9% and 88.6%, respectively. The releases of silver ion of PSt-AgNPs containing 5 wt% OEO in different foods were 9.31% for deionized water, 7.48% for ethanol and 24.51% for acetic acid. These values were lower than the requirements of European Standard EN 1186-1:2002. The incorporation of green synthesized AgNPs using OEO and PSt thus improved the bioactive nanocomposite film performance for food packaging applications.

Automated summary

Green synthesized silver nanoparticles (AgNPs) using oregano essential oil (OEO) and PSt displayed improved antibacterial activity, lower release of silver ion, and enhanced water resistance. The incorporation of 5 wt% OEO in PSt-AgNPs showed the minimum inhibitory concentration against Escherichia coli and Staphylococcus aureus. The synergistic effect in antibacterial activity was achieved when combining AgNPs and OEO in the PSt film.