Structural, physicochemical and rheological characterization of Tacca involucrata starch

Starch was isolated from white and yellow Tacca involucrata tubers and the characteristics studied. The granule morphology was the same for both starches but they differed in granule size distribution: white tacca (6.13-18.12 mu m), yellow tacca (4.19-11.98 mu m). Yellow tacca exhibited an A-type X-ray diffraction pattern but white tacca had a C-type diffraction pattern. White tacca had a slightly higher weight average M(w) (2.12 x 10(7) g/mol) than yellow tacca (1.85 x 10(7) g/mol). Yellow tacca had lower gelatinization temperature, higher swelling power, higher amylose leaching and higher freeze-thaw stability compared with white tacca. However, the flow characteristics and small deformation mechanical spectra of the starch gels did not differ greatly. The high paste clarity of tacca starches at higher starch concentrations indicates a potential for application in food products like pies and puddings where clarity is desirable. (C) 2011 Elsevier Ltd. All rights reserved.