Comparison of observed rheological properties of hard wheat flour dough with predictions of the Giesekus-Leonov, White-Metzner and Phan-Thien Tanner models

The measured rheological behavior of hard wheat flour dough was predicted u sing three nonlinear differential viscoelastic models. The Phan-Thien Tanne r model gave good zero shear viscosity prediction, but overpredicted the sh ear viscosity at higher shear rates and the transient and extensional prope rties. The Giesekus-Leonov model gave similar predictions to the Phan-Thien Tanner model, but the extensional viscosity prediction showed extension th ickening. Using high values of the mobility factor, extension thinning beha vior was observed but the predictions were not satisfactory. The White-Metz ner model gave good predictions of the steady shear viscosity and the first normal stress coefficient but it was unable to predict the uniaxial extens ional viscosity as it exhibited asymptotic behavior in the tested extension al rates. It also predicted the transient shear properties with moderate ac curacy in the transient phase, but very well at higher times, compared to t he Phan-Thien Tanner model and the Giesekus-Leonov model. None of the model s predicted all observed data consistently well. Overall the White-Metzner model appeared to make the best predictions of all the observed data.