Isolation and physicochemical characterization of godare (<i>Colocasia esculenta</i>) starch from Ethiopia

Abstract

Physicochemical properties of starch isolated from tuber of Godare [Colocasia esculenta (Araceae)] have been characterised. Amylose content was found to be 24.3%. The starch granules are polygonal to spherical in shape with indentations in some granules. The granules exist as single entities. The starch has normal granule size distribution with mean particle size of 13μm. The true density was found to be 1.347 g/ml. The moisture sorption pattern and swelling power of Godare starch were similar to that of potato starch. The Xray diffraction pattern of Godare starch is typically B-type with distinctive maximum peak at around 17° 2θ. Barbender viscosity (6% on dry basis) showed much lower peak viscosity (157 BU) and breakdown viscosity (6 BU) than potato starch. Godare starch exhibited a DSC gelatinisation temperature of T-onset (63°C), T-peak (68°C) and T-end (75°C) with enthalpy of gelatinisation (ΔH, 11.5 mJ/mg). Keywords: Colocasia esculenta starch, granule size, X-ray diffraction, amylograph, DSC-gelatinisation

Ethiopian Pharmaceutical Journal Vol. 24, 2006: 13-22