Physicochemical and functional properties of dialdehyde polysaccharides crosslinked gliadin film cooperated by citric acid

Aldehydes are effective crosslinkers for fabricating protein-based films. Herein, dialdehyde polysaccharides (DPs) were synthesized and applied to prepare the functional gliadin films cooperated by citric acid. The physicochemical properties of the gliadin film-forming solutions and functional properties of the films were fully explored, as well as the formation mechanisms of the films were investigated. Results showed that all the DPs crosslinked gliadin films had a transparent and ultraviolet resistance property. And the mechanical properties, water-resistant properties, thermal stability, antibacterial properties of the gliadin films were all advanced by DPs, in which dialdehyde dextrin crosslinked gliadin films (DAD-film) showed the best performances. And the Schiff base bonds, hydrophobic interactions, and hydrogen bonds were the main molecular interactions in the DPs crosslinked gliadin films, which worked together to achieve the related properties of the films. Therefore, the DPs, especially DAD, could be a potential crosslinker to fabricate the gliadin-based films with functional properties. And this research will highlight the new strategies for the usage of gliadin or other cereal prolamins for packaging.