▎ 摘 要
The present study aimed to develop an antibacterial packaging system based on biodegradable polyvinyl alcohol (PVA) polymer. Box-Behnken design was used to investigate silver oxide nanoparticles, graphene oxide and tragacanth gum as film additives to obtain maximum antibacterial activity against Staphylococcus aureus and Escherichia coli. The experimental design showed the inhibitory effect of graphene oxide and tragacanth gum on the antibacterial activity of PVA films containing Ag2O nanoparticles. The optimum film containing 5% Ag2O nanoparticles (% of PVA weight) was prepared and characterized using scanning electron microscopy and energy-dispersive X-ray spectroscopy (SEM-EDS), Fourier transform infrared spectroscopy (FTIR) and thermogravimetric/differential thermal analyser (TG-DTA). Results of this study showed the formation of PVA film with 0.04-mm thickness, with a higher density of Ag2O nanoparticles (25- to 75-nm size) around the upper surface. Compared with blank PVA film, the optimum film showed higher tensile strength and thermal stability. It was also more efficient in water vapour and oxygen barrier properties, along with preserving raw beef samples by inhibiting the growth of beef natural bacteria for at least 7 days, when stored in the refrigerator.