Functional properties and formation mechanisms of dialdehyde polysaccharides crosslinked gliadin-films enforced by alkaline condition

Abstract

BACKGROUND: The usage of natural polysaccharides is attractive to researchers around the world. At the same time, non-/low-toxic crosslinkers prepared by polysaccharides are expected to fabricate protein-based films in many fields. Herein, different dialdehyde polysaccharides (DPs) were successfully synthesized and applied to prepare gliadin-films under alkaline conditions. The functional properties and formation mechanisms of the films were fully investigated. RESULTS: The results showed that the mechanical properties, water-resistant properties, thermal stability, and antibacterial properties of the gliadin-films were improved by DPs and alkali treatment. Particularly dialdehyde dextrin (DAD) crosslinked gliadin-films showed the highest tensile strength, but no additional effect on their elongation, or advancement on the other functional properties. The film-forming mechanisms indicated that Schiff base bonds, hydrophobic interactions, electrostatic interactions, and hydrogen bonds were the main forces in the films, supporting their improvement in functional properties. CONCLUSION: DPs, especially DAD, can be a promising crosslinker in fabricating gliadin-films. These findings have shown great promise to seek an effective crosslinker for fabricating gliadin/protein-based packaging. © 2023 Society of Chemical Industry.