Concentration-dependent rheological characteristics of chickpea (Cicer arietinum L.) flour dispersion in steady and dynamic shear

Abstract

Chickpea (Cicer arietinum L.) flour (CF) is the basic raw material used in the form of dispersion in varied concentrations for making promising oriental sweets and snacks in the Asian subcontinent. The finished product quality of these fried food items thus mainly depends on the consistency of flour dispersions. Therefore, a concentration-dependent steady-state and dynamic rheological study, along with the pasting behaviour, was carried out. Steady shear rheology exhibited concentration-dependent pseudoplastic behaviour with significantly higher apparent viscosity for 40 - 45% CF dispersions, and a desirable consistency to be used in making fried sweets and snacks. The Herschel-Bulkley model described dispersions better at 5 - 20%, while Mizrahi-Berk at 25 - 50%. Hahn Ree-Erying's model described thixotropic behaviours for time-dependent flow; increasing CF concentration from 30 - 50% and increasing storage (G') and loss (G'') modulus in the linear viscoelastic region. However, G' values were dominant over G'' values in the small amplitude region, showing elastic behaviour, whereas viscous behaviour was exhibited in the higher amplitude region. During heating (30 - 80°C) in the temperature sweep test, concentrated samples (30 - 50%) showed a drastic increase in G' and complex viscosity (η*), while in cooling stages (95 - 25°C), a 25% concentration sample resulted in the highest values of G', G'', and η*.