ROLE OF GRANULE SIZE AND SIZE DISTRIBUTION IN THE VISCOSITY OF COWPEA STARCH DISPERSIONS HEATED IN EXCESS WATER
P.E. Okechukwu, M.A. Rao
Journal of Texture Studies
Abstract
ABSTRACT The role of granule size and size distribution, measured by laser diffraction, in affecting the flow behavior and yield stress of cowpea starch dispersions (2.6% w/w) heated for various time intervals at 67, 70, 75 and 80C was studied. Flow data on the dispersions at 20C were fitted to the power law flow equation. The standard deviation of the granules described the transition of flow behavior from shear thickening (dilatant) in the early stages of gelatinization to shear thinning (pseudoplastic) in the latter stages. It was an important variable for also correlating the critical shear rate, λ˙c, for the onset of shear thickening in starch dispersions. The granules swelled to a maximum of about 3.5 X raw starch granule mean diameter and a granule mass fraction of 65%. The consistency index of the dispersions increased with granule mean diameter.
Extracted Claims
5 claims extracted from this paper into the knowledge graph
granules swelled to maximum size
“The granules swelled to a maximum of about 3.5 X raw starch granule mean diameter and a granule mass fraction of 65%.”
granule mean diameter increased consistency index
“The consistency index of the dispersions increased with granule mean diameter.”
cowpea starch dispersions heated at various temperatures
“The role of granule size and size distribution, measured by laser diffraction, in affecting the flow behavior and yield stress of cowpea starch dispersions (2.6% w/w) heated for various time intervals...”