Rheological properties of corn meal dough / Propiedades reológicas de la pasta de harina de maíz

Abstract

The rheological properties of cooked corn meal dough were determined by squeezing flow, steady shear, and dynamic shear rheological methods. Under biaxial extension, the material exhibited strain- thinning behavior and the normal stress difference could be modeled as a function of biaxial strain rate, with a flow behavior index, n, of 0.38-0.52 and the biaxial consistency coefficient, Kb, ranging from 4.63 x 107 to 9.75 x 107 Pa.s". Steady and dynamic shear studies suggest that the dough exhibits shear-thinning behavior at a shear rate range of 1-40 s-1 and more viscous-like characteristics under dynamic conditions (0.5-10 s-1 frequency). Particle size distribution of the corn meal may affect some of the rheological properties ( K b, K, n) of the cooked dough. Further research is necessary to establish correlation between material variation and product quality for improvement of processes such as extrusion, baking or frying.