Viscoelastic properties of wheat gliadin and glutenin suspensions

Linear and non-linear rheological properties of wheat gliadin and glutenin suspensions were investigated at various concentrations. Linear dynamic viscoelastic properties for both gliadin and glutenin were strongly dependent on concentration. For gliadins, the storage moduli (G′), loss moduli (G″), and phase shifts dramatically changed within a narrow concentration range, indicating that gliadin suspension properties changed from viscous to viscoelastic. Glutenins exhibited viscoelastic solid behaviour at all measured concentrations. The non-linear shear viscoelastic properties of gliadin and glutenin also depended on concentration. Viscosities of gliadins displayed shear-thinning behaviour; viscosities for glutenins showed shear-thickening behaviour at low shear rates, and shear-thinning behaviour at higher shear rates. Our results indicate that gliadin’s structure in suspension changes over a small concentration range, and suggest that gliadin is important in adjusting and controlling gluten’s viscoelastic behaviour, and not only as a diluent of gluten’s functional properties.