Capillary rheology is a technique based on the application of
high stresses and high shear rates during the extrusion of the
material through a capillary die (Macosko, 1994). Determination of
the pressures necessary to force the material through the capillary
die with a given flow rate as well the expansion swelling at the exit
of the capillary enable the determination of shear and extensional
viscosity of the material (Macosko, 1994). The concept of capillary
rheology is similar to fluid flow in pipes and extrusion dies, which
makes it suitable to study the rheological properties of extruded
products (Macosko, 1994). A capillary rheometer can be adapted to
the characterization of shear sensitive fluids such as wheat flour
dough (Cuq et al., 2002) therefore its utilization for the characterization
of pasta dough is justifiable.