The influence of different cross-linking reactions and glycerol addition on thermal and mechanical properties of biodegradable gliadin-based film

In this study gliadin solutions previously cross-linked by 1-(3-dimethylaminopropyl)-3-1-ethylcarbodiimide hydrochloride/n-hydroxysuccinimide (EDC/NHS) and l-cysteine were prepared with different plasticizer concentrations. The obtained films were investigated through mechanical behavior (Young's modulus and elongation at break), thermal characteristics (differential scanning calorimetry and thermogravimetric analysis), swelling and water solubility, FTIR measurements and scanning electron microscopy. The relationships between the gliadin structure and the mechanical, thermal and morphological properties were affected by protein conformational changes during the cross-linking reaction. On the other hand, the reaction mechanism was strongly dependent on the glycerol content.