On the Use of Conventional Dough Extension Tests in Characterising Flours for Dough Sheetability. I. Experiments

Dough extension tests are used in industry to rate flours for dough processability. The results impact flour selection for product use. Previously, it was shown that dough extension data correlated poorly with dough sheetability irrespective of whether doughs were tested fresh or rested. It was noted that sample shapes varied between specimens of flours. To understand how sample shape affects extensigraph tests, a finite element (FE) simulation-based approach was taken. Real extensigraph samples were drawn on a computer equipped with the commercial FE package ABAQUS and using the anisotropic Bergstrom Boyce model with Mullins damage (ABBM) constitutive model to describe the dough's rheology. Results show that the force-extension traces were affected by sample shape, and that thinning occurs more from the sides than the bulk for slumped samples. The FE predictions for sample shape effects on hook force were validated against real tests. Similar dependencies on sample shape are also predicted for the alveograph and Kieffer micro-extensigraph tests.