Development and characterization of chitosan-based antimicrobial films: A sustainable alternative to plastic packaging

The development of biodegradable bioplastic packaging is essential for reducing environmental pollution and minimizing non-biodegradable waste accumulation. In this study, a biodegradable plastic film was fabricated by blending polyvinyl alcohol (PVA), chitosan (CS) derived from shrimp shells, and gelatin (GE) in a 6:2:2 ratio. Crosslinked chitosan and zinc oxide nanoparticles (ZnONPs) at a 95:5 ratio was incorporated into the matrix, and the bioplastic film was produced via a simple solution casting method. The developed composite underwent extensive characterization, including FTIR, UV–Vis, TGA, XRD, and SEM analyses. Results indicated high thermal stability and homogeneity, as confirmed by TGA and SEM. The bioplastic exhibited superior mechanical properties, with a tensile strength of 64.68 MPa and an elongation at break of 25.38 %, along with optimal density, thickness, water absorption, and a suitable melting point. Biodegradation studies showed 80.92 % degradation in two months by soil microbes, and biotoxicity tests confirmed its safety for crops (rice seeds). Additionally, the bioplastic, containing 15.2 % chitosan, demonstrated significant antibacterial activity against both gram-positive and gram-negative bacteria, highlighting its potential as a sustainable alternative for food packaging. This study presents a promising bioplastic film with the potential to replace conventional non-biodegradable packaging while enhancing food safety through its antibacterial properties.