Fabrication of antimicrobial packaging based on polyaminopropyl biguanide incorporated pectin/polyvinyl alcohol films for fruit preservation

Pectin (PEC)/polyvinyl alcohol (PVA), plasticizers, and polyaminopropyl biguanide (Pb) (0.125%-1%) were used to prepare the film solution. The results demonstrated significantly enhanced tensile strength and elongation at break of PEC/PVA/Pb 0.25% film than PEC/PVA film. Scanning electron microscopy was carried out to investigate the continuous and dense structure of the PEC/PVA/ Pb0.25% film. FTIR, XPS, and XRD revealed that Pb addition to the PEC/PVA film matrix changed its physicochemical properties by forming new hydrogen and CN bonds. Moreover, the composite films exhibited strong antimicrobial activity against food-borne microorganisms (E. coli and S. aureus), and post-harvest pathogens (P. italicum and F. proliferatum) in vitro. The composite film effectively inhibited P. italicum growth during citrus experiments, while maintaining nutritional components (vitamin C, total flavonoid, and total polyphenol content). Overall, the antimicrobial composite film presented promising applicability in food packaging.