The effects of zinc oxide nanoparticles on the physical, mechanical and antimicrobial properties of chicken skin gelatin/tapioca starch composite films in food packaging

The aim of this study was to characterize chicken skin gelatin/tapioca starch composite films with varying concentrations (0-5%) of zinc oxide nanoparticles using the casting technique. The incorporation of 5% zinc oxide nanoparticles increased the water vapor permeation (1.52-1.93 × 10-7 gmm/cm2hPa) and melting temperature of the films. The tensile strength (22.96-50.43 MPa) was increased, while elongation at break decreased with increasing concentrations of zinc oxide nanoparticles. The structures of the films were also investigated via Fourier transform infrared spectroscopy. The inhibitory zones for both the gram-positive (Staphylococcus aureus) (16-20 mm) and gram-negative (Escherichia coli) (15-20 mm) bacteria were larger in the film with 5% zinc oxide. Overall, chicken skin gelatin-tapioca starch composite films with 3% zinc oxide nanoparticles were found to have the optimal formulation, demonstrating good physical, mechanical and antibacterial properties. Gelatin-based composite films with nanoparticle incorporation show strong potential for use in biodegradable food packaging materials.