Dynamic rheology of corn starch–sugar composites Original Research Article

The effect of sugars (sucrose, glucose, and xylose) at different concentrations (0%, 10%, 20%, and 30%) on dynamic rheological properties of corn starch pastes (5% w/w) was investigated by small-deformation oscillatory measurements of storage moduli (G′) during cooling and aging. Magnitudes of G′ increased sharply during cooling (from 95 to 4 °C) and decreased with increase in concentration of sugar. The xylose was found to show the greatest reduction in the values of G′ among the sugars tested. G′ values as a function of aging time (10 h) at 4 °C increased rapidly at initial stage and then reach a pseudoplateau region at long aging times. Increasing the sugar concentration resulted in the decrease in pseudoplateau values. In general, G′ values in corn starch–sugar composites were reduced in the presence of sugars, and decreased in the following order: xylose > sucrose > glucose > control (no sugar).