Retrogradation of Gelatinized Potato Starch Studied by Differential Scanning Calorimetry

The retrogradation process of gelatinized potato starch was studied by DSC as a function of the aging temperature and water content. Differences in the retrogradation states dependent on these parameters were revealed by the pattern of the DSC curves. Potato starch aged at a low temperature after gelatinization gave a low endothermic onset temperature. As the starch content increased, retrogradation proceeded over a wider temperature range. The retrogradation proceeded even at 50°C for a starch content of 50%. The gelatinization enthalpy for granular starch was found to be 4 ~ 4.5 cal/g of dry starch. By contrast, the maximum gelatinization enthalpy obtained for retrograded starch was found to be as low as 2.5 cal/g of dry starch.