Rheology of Bengal gram ( Cicer arietinum) flour suspensions

Abstract

Shear rate-shear stress data of Bengal gram ( Cicer arietinum) flour suspensions were obtained using a concentric cylinder viscometer. The effect of concentration (30, 33, 36, 39, 42, 45 and 48% flour) and particle size (60–85, 85–100, 100–120, 120–150 and 150–170, British Standard sieves) on flow behaviour index, consistency index and apparent viscosity were investigated. The Bengal gram flour suspension was pseudoplastic and exhibited yield stress. The Herschel-Bulkley model was applicable for fitting the shear rate-shear stress data (r 2 ≥ 0·95, p ≤ 0·01). The thixotropic characteristics of the fluid were studied at shear rates of 85·1 and 1337·6 s −1 at 42% flour concentration for coarse (60–85) and fine (150–170) fractions. The equilibrium shear stress, and thixotropic coefficients with time and with increasing shear rate were also computed. Particle size and concentration of flour strongly influenced the rheological behaviour of the suspension.