Development of garlic extract-loaded zinc oxide nanoparticle/chitosan/polyvinyl alcohol nanocomposite-based active eco-friendly packaging films for extending shelf-life of fish fillets.

This study presents the design and functional evaluation of a biodegradable nanocomposite film (CPZG) composed of chitosan, polyvinyl alcohol (PVA), zinc oxide nanoparticles (ZnONPs), and garlic extract (GE) for active fish packaging. The film was fabricated via solvent casting and characterized using FTIR, SEM, XPS, and EDX, confirming successful molecular-level integration and uniform dispersion of ZnONPs and phytochemicals. GC-MS profiling revealed key organosulfur compounds such as diallyl disulfide and allyl trisulfide, with evidence of both sustained release and long-term retention within the polymer matrix. Functionally, CPZG exhibited excellent mechanical integrity (tensile strength: 30.1 MPa; elongation: 203 %) and thermal stability. Its enhanced hydrophobicity (contact angle: 83.1°), low solubility (17.65 %), reduced moisture content (9.37 %), and superior barrier properties including low water vapor (4.73 × 10-11 g/m2/s) and oxygen permeability (4.76 × 10-13 g/m2/s) support its suitability for moisture-sensitive applications. The film also showed strong UV-blocking efficiency with a transmittance of only 10.27 % at 280 nm and demonstrated notable antioxidant potential (49.78 % DPPH inhibition at 500 mg/mL). The CPZG film significantly reduced microbial load on fish fillets, lowering CFU counts from uncountable in polyethylene-packaged samples to just 50 CFU/mL after 5 days of refrigerated storage. Time-kill assays confirmed bactericidal action against fish borne pathogens like P. aeruginosa, and S. typhi. Release kinetics in both 10 % ethanol and deionized water simulants followed a non-Fickian (anomalous transport) mechanism, as modeled by Korsmeyer-Peppas and Peppas-Sahlin equations, ensuring sustained delivery of bioactives. Migration studies demonstrated controlled Zn2+ ion release, with values remaining within regulatory safety limits, ensuring food contact compliance. Biodegradation under soil burial conditions resulted in a 26.92 % weight loss over 21 days, with minimal ZnONP leaching, indicating the film's environmental safety. Overall, the CPZG film integrates mechanical durability, broad-spectrum antimicrobial activity, controlled release, food safety, and eco-compatibility, offering a promising, cost-effective alternative to synthetic packaging materials for seafood preservation.