Characterization and application of active films based on commercial polysaccharides incorporating ZnONPs

In the face of the environmental problems caused by using food packaging composed of non-renewable sources, the aim of this study was producing a new antimicrobial film, biodegradable and with UV barrier based on commercial κ-carrageenan/starch polysaccharides loaded zinc oxide nanoparticles (ZnONPs) for the first time by casting method. Different formulations of κ-carrageenan/starch/ZnONPs were extensively characterized. The X-ray patterns displayed diffraction peaks characteristics of the crystallographic plane of ZnONPs. The formation of the material composite was confirmed by specific signals in the FTIR spectrums and endothermic peak shift after ZnONPs addition. The ZnONPs (1.5 and 2 %) produce a more resistant material. The analysis of SEM (cracks remotion of film surface), mechanical properties (higher elongation at rupture and tensile strength), and opacity (low transparency) confirm this. Still, ZnONPs at 2 % produce a hydrophobic surface, justified by lower moisture content, water solubility, and higher WCA. The ZnONPs promoted UV barrier and antimicrobial activity against Escherichia coli, Salmonella Typhimurium, and Staphylococcus aureus microorganisms. Thus, the new active material was applied as a coating on fresh strawberries and delayed the ripening of the fruit, extending its shelf life. Therefore, we produced, characterized, and applied an active material with potential application in fresh food packaging.