Multifunctional nanocomposite active packaging materials: Immobilization of quercetin, lactoferrin, and chitosan nanofiber particles in gelatin films

The design and fabrication of multifunctional films from natural materials is a major focus of modern packaging research with the aim of creating smart, active, and/or biodegradable packaging. In this study, multifunctional films were created by embedding different kinds of functional nanoparticles into a gelatin-based film prepared by a casting method. The nanoparticles were prepared by crosslinking cationic chitosan nanofibers using anionic sodium tripolyphosphate ions. In some cases, quercetin, lactoferrin, or both were incorporated into these nanoparticles. The nanoparticles were mixed with the hot gelatin solution prior to casting. The appearance, lightscreening, water vapor barrier, thermal, mechanical, antimicrobial, antioxidant, and biodegradability/composting characteristics of the nanoparticle-loaded films were then characterized. Dynamic light scattering showed that the size, polydispersity, and charge of the functional nanoparticles depended on their composition. The spectroscopic analysis identified the importance of electrostatic and hydrogen bonds in film formation. Incorporation of the functional nanoparticles into the gelatin films improved their optical, mechanical, barrier, and preservative properties. For instance, the incorporation of quercetin increased the ability of the films to screen UV-light, whereas the incorporation of both lactoferrin and quercetin increased the antimicrobial and antioxidant properties of the films. Finally, the films were shown to have good biodegradability/composting under environmental conditions, which is important for reducing the negative environmental impacts caused by synthetic packaging.