Rheological Characteristics of Fresh and Dried Okra Dispersions

Abstract

The rheological properties of fresh and dried okra dispersions were investigated at different temperatures using power-law model. Sun-dried and oven-dried okra dispersions were more viscous than the fresh okra dispersion. All samples exhibited pseudoplastic behaviour with flow indices of 0.220 ≤ n ≤ 0.319, 0.182 ≤ n ≤ 0.323, and 0.120 ≤ n ≤ 0.348, respectively for oven-dried, sun-dried and fresh okra dispersions with shear thinning  effect. An increase in temperature decreased apparent viscosity. The  consistency coefficient, k, and the flow behaviour index, n, decreased with increasing heating temperature. The Arrhenius type equation was used to  study the temperature dependence with activation energies of 10.08, 8.20 and 6.22 KJ/mol for fresh, sun-dried and oven-dried okra dispersions  respectively. The relationship between the power-law parameters and temperature was analyzed.