Effect of endogenous wheat gluten lipids on the non-linear rheological properties of the gluten network

The impact of endogenous wheat lipids on thermal characteristics, mixing behavior, non-linear rheological properties of gluten was studied to explore the contribution of wheat lipids to viscoelastic behavior of gluten under large processing deformations. Thermal analysis indicated higher denaturation temperature for vital wheat gluten (VWG) (69.2 ± 1.2 °C) due to reduced water affinity compared to lipid-removed vital wheat gluten (LRVWG) (63.6 ± 0.2 °C). Development time was reached 4 minutes earlier and consistency increased constantly for LRVWG as Farinograph mixing proceeded, suggesting higher affinity to water for gluten in the absence of lipids. Large Amplitude Oscillatory Shear (LAOS) tests showed a mixture of type III and IV non-linear behavior for gluten. Higher tendency to type III behavior for VWG indicated more extensibility in the presence of lipids. Higher elasticity and strain stiffening obtained for LRVWG under LAOS deformations accentuated the stabilizing effect of lipids on the viscoelastic nature of gluten network during processing.