Granulometric structure, zeta potential and differential scanning calorimetry of native starch powders from Dioscorea spp

Abstract

Starch powders from two cultivars of Dioscorea rotundata (DR) were analysed on the physicochemical aspect. Granulometric structure, zeta potential and differential scanning calorimetry of starch powders showed the following properties. Various shapes with predominance of granule ranging from 10 to 40 μm were noted. The zeta potential of DR went from positive values to negative values as the pH was increasing from 2 to 8. From pH 2 to 4, the zeta potential was positive. A significant difference was obtained between each value (p > 0.05). The zeta potential took a negative value from pH 5 and above. The results of thermal analysis show that starches start swelling at 68.91.5 C. Enthalpy of gelatinization was about 15 J.g-1.