Cellular structure and rheological properties of shaped fermented wheat flour dough
Résumé
Among the various operations of the breadmaking chain, the impact of shaping on dough cellular structure has scarcely been studied. In this work, wheat flour dough has been laminated under different roll gap conditions delta(mm)= (2,5,10, 20, infinity). Rheological properties were measured under large and small strains, by lubricated squeezing flow test and dynamic thermomechanical analysis, respectively. Laminating has a limited effect on the elongational viscosity of the dough. However, the minimum value of the ratio of storage modulus reached for gap delta = 5 mm suggests that gluten network structuration is improved in this case. The kinetics of porosity and shape ratio of fermenting laminated doughs were calculated from image analysis of dough follow-up during proofing. They showed that stability is improved for delta = 5 mm. Finally, Xray tomography experiments, performed on laminated rolled dough during proofing, confirmed that the main changes can be attributed to an increase of cellular homogeneity at delta = 5 mm, reflected by lower median gas cell size and less spread size distributions.
