Physical, Thermal and Sorption Profile of Starch Obtained from Tacca leontopetaloides

摘要

The purpose of this study was to elucidate functional properties of starch granules obtained from tubers of Tacca leontopetaloides and compare them to a commercially available maize starch. Scanning electron microscopy (SEM), particle size analysis, X-ray powder diffraction (XRPD), gravimetric moisture sorption, and differential scanning calorimetry (DSC) were used to characterize the samples. Tacca starch exhibited a monomodal distribution of irregularly shaped granules with a mean particle size of2.64 (am. The spherulites of both samples indicated an A-type pattern, with the degree of crystallinity estimated to be 35% for tacca starch and 38% for maize starch. The moisture sorption profile of both samples was analyzed according to the Guggenheim,Anderson and de Boer (GAB) equation. GAB analysis estimated the monolayer coverage for tacca and maize starch to be 0.0928 g/g and 0.0856 g/g, respectively. The gelatinization parameters of tacca starch were found to be 65.57 - 68.56 - 73.10°C while that of maize starch were 67.30 - 70.97 - 76.25°C. The results of DSC studies indicate that the associative forces that stabilize the granule structure in tacca starch are weaker than those in maize starch. The results obtained in this study establish thefundamental characteristics of tacca starch and suggest that further exploration of its potential for use in a variety of fields is warranted.