Integration of Zinc Oxide Nanoparticles in Wheat Gluten Hydrolysates-Development of Multifunctional Films with Pliable Properties

Biodegradable wheat gluten hydrolysates (WGH) and zinc oxide nanoparticles (ZNPs) with cross-linkers were prepared as nanocomposite films. The physiochemical analysis demonstrated the formation of ZNPs of size approximately 18.37 nm with spherical and hexagonal nanostructures. The ZNPs are endowed with different functional groups, as corroborated by X-ray diffractogram (XRD), field emission electron microscopy (FE-SEM), and fourier transform infrared spectroscopy (FT-IR), respectively. XRD and functional group patterns (IR) of WG and ZNPs exhibited minor changes during film development, indicating a successful interaction between the components. The SEM analysis revealed that the integration of ZNPs into the wheat gluten polymer promoted nano-aggregation on the film surface and the cross-section. The swelling capacity of films was found to be highest by WG/PVP/ZNPs with 265% (pH 7) and 198% (at pH 9). The antibacterial assessments revealed the sensitivity of Pseudomonas aeruginosa and E. coli toward WG/PVP/ZNPs with 14 and 13 mm zone of inhibition, demonstrating the maximum release of zinc ions from WG/PVP/ZNPs films. Furthermore, the WG/PVP/ZNPs film exhibits maximum oxidant scavenging (84%) and oxidant quenching potential (75%). The findings suggest that casting of WGH with ZNPs has a remarkable effect on the films’ physical and biological properties, allowing for their potential use as future bioplastics in biomedical and industrial sectors.