A fundamental rheological approach to determine the optimum water absorption capacity of a model gluten-free dough system: soy flour dough.

Background: Determining the optimum water absorption capacity of gluten-free flours for an improved breadmaking process has been a challenge because there is no standard method. In the present study, large amplitude oscillatory shear (LAOS) tests were performed to explore the impact of different levels of added water on non-linear viscoelastic response of soy flour dough in comparison to wheat flour dough at a consistency of 500 BU.

Results: Among the LAOS parameters, large strain modulus (G'_L) and large strain rate viscosity (η'_L) were found to better probe the impact of added water amount on non-linear viscoelastic properties of soy flour dough. Although soy flour dough with 160:100 (water: soy flour, v/w) and wheat flour dough had overlapping η*(ω) in the linear viscoelastic region, LAOS sweeps revealed similar tan δ, G'_L and η'_L values along with similar elastic and viscous Lissajous-Bowditch curves at γ₀ = 200% for soy flour dough with 175:100 (water: soy flour, v/w) to those of wheat flour dough.

Conclusion: Considering the large deformations involved in breadmaking process and the poor capability of the linear viscoelastic measures to predict loaf volume, the present study suggests using the LAOS parameters to determine the optimum water absorption capacity and to optimize the strain-stiffening and shear-thinning behaviors of gluten-free flours to improve end-product quality. © 2025 Society of Chemical Industry.