Rheological properties of short doughs at large deformation

Large deformation rheological properties of short doughs of various composi tion were determined in uniaxial compression. Apart from a sugar-ii-ee doug h, all doughs studied showed pronounced yielding and flow behaviour. Yieldi ng occurred at very small strain, indicating strong strain dependence. At s mall strain, systems were predominantly solid-like; at large strain they be haved more like strain-rate thinning liquids. The doughs showed large diffe rences in apparent biaxial extensional viscosity, depending on fat and sucr ose contents. It is concluded that yielding behaviour is strongly influence d by intact flour particles that act as defects in the material. The occurr ence of such particles is determined by the presence of sucrose, which dela ys gluten development through its effect on solvent quality. The sucrose al so facilitates formation of a non-fat continuous phase, since it increases the quantity of solvent. (C) 1999 Academic Press.