Pasting, rheological properties and gelatinization kinetics of tapioca starch with sucrose or glucose

Effects of sugars (sucrose and glucose) on the pasting, theological and thermal properties of tapioca starch (TS) were studied. Rapid visco-analyser (RVA) and differential scanning calorimetry (DSC) showed that pasting and gelatinization temperature of IS increased with increased sugar concentration in the order of sucrose > glucose. Peak, breakdown, final and setback viscosities tended to increase with increased sugar content. Rheological parameters calculated from Herschley-Bulkley model showed sugar addition increased the yield stress and consistency coefficient, while decreased the thixotropy of IS gels. Loss tangent determined from dynamic viscoelastic tests revealed that sugars increased the solid-like characteristics of TS gels. Kinetics analysis showed E-a raised and rate constants declined in the presence of sugars. suggesting the same sugar effect as the experiments of RVA and DSC. And thus kinetics analysis could provide new evidences for the influence of sugars on starch gelatinization. (C) 2012 Published by Elsevier Ltd.