Effect of enzymatic glycosylation on the structure and properties of wheat gluten protein fibers

Wheat gluten proteins are good raw materials for preparing fibers due to their excellent viscoelasticity. However, protein fibers made directly from wheat gluten have poor mechanical properties. In this paper, transglutaminase was used to induce the glycosylation reaction between wheat gluten proteins and carboxymethyl chitosan. The glycated proteins were then made into fibers by wet spinning. After glycosylation modification, the breaking strength and breaking elongation of the wheat gluten protein fibers (WGPF) improved by 43% and 127%, respectively. Fourier transform infrared spectroscopy and sodium dodecyl sulfate-polyacrylamide gel electrophoresis analyses revealed that the glycosylation-modified WGPF molecules contained saccharide portions, which confirms the covalent attachment of carboxymethyl chitosan to the wheat gluten protein. Scanning electron microscopy showed that the number of pores in the cross-section of the modified WGPF was lower than that in the unmodified WGPF. The thermal stability and dyeability of the modified WGPF were also improved.