Active and intelligent packaging films based on PVA/Chitosan/Zinc oxide nanoparticles/Sweet purple potato extract as pH sensing and antibacterial wraps

With growing concerns about the environmental impact of petroleum-based products, researchers are exploring new materials for food packaging. One promising avenue is the use of nanotechnology and natural materials. In this study, active and intelligent composite films were developed by solvent casting method using polyvinyl alcohol (P), chitosan (C), zinc oxide nanoparticles (Z), and sweet purple potato extract (S). The results demonstrated that C and Z did not affect the pH-based structural transformation of pigment (S)-containing PVA solutions. SEM microstructural observation revealed a uniform distribution of zinc oxide nanoparticles in the polymeric matrix. The addition of C and Z to the composite film improved its thermal, water barrier, and antibacterial and antioxidant properties. The tensile strength of the neat film (P) was 13.0 MPa and increased to 30.8 MPa for PCZS composite film because of the good interaction between PVA and the additives. The strong antimicrobial activity of PCZS composite films against environmental pathogens was validated by antimicrobial barrier analysis. Additionally, the functional composite film (PCZS) efficiently detected chicken freshness as a function of pH change. These findings suggest that the PCZS film has great potential as a smart and active food packaging material or as an antimicrobial wrap.