Production and characterization of composite films with zein nanoparticles based on the complexity of continuous film matrix

Abstract

Zein nanoparticles (ZNPs) can be fabricated by applying the “anti-solvent” method, in which, zein molecules interact with components existing in the bulk aqueous system and affect their final properties. In this study, bio-nanocomposite films with ZNPs incorporated into different polysaccharide-based matrices, Konjac glucomannan (KGM) or/and Chitosan (CS), were successfully fabricated employing anti-solvent and solvent casting methods. Physiochemical characterizations of both the composite film-forming solutions and the final composite films were systematically studied to evaluate the impact of the complexity of continuous film matrices on the functionality of ZNPs-incorporated composite films. The results showed that ZNPs can be uniformly embedded in the film matrices, significantly enhancing the overall physicochemical performance of the final composite films. The exitance of intermolecular hydrogen bonding interactions among the film components, the changes in the crystallinity of the films, and a more compact and uniform microstructure were confirmed by preforming Fourier transform spectroscopy, X-ray diffractometry, and scanning electron microscopy, respectively. The active nanofiller effect of ZNPs and the synergism of KGM and CS, benefitted the most enhanced properties of KCZ composite film, which is not very sensitive to moisture, unlike KZ composite film, and not very rigid, unlike CZ composite film.