Differential scanning calorimetry: gelatinisation of sago starch in the presence of sucrose and sodium chloride

The effect of sucrose and sodium chloride (NaCl) on sage starch gelatinisat ion was investigated by differential scanning calorimetry (DSC). The gelati nisation of starch in the presence of low levels of water and high levels o f sucrose was studied. The gelatinisation temperature was found to increase in the presence of sucrose, whereas the gelatinisation enthalpy was unaffe cted. The gelatinisation temperature range was not as broad in the presence of sucrose as without sucrose. Furthermore, the shape of the gelatinisatio n endotherm was changed by the addition of sucrose. The double endotherm ob tained in limited water-starch systems was changed into a single endotherm, similar to the endotherm obtained in excess water-starch systems at higher temperature. DSC was also used to examine the effects of water and NaCl co ntent on the phase transitions of sage starch. Samples were adjusted to sta rch-water weight ratios of 2:3 and 3:2 in NaCl concentrations from 1 to 5 M . The gelatinisation temperature of sage starch increased and then decrease d as the NaCl concentration increased. NaCl created similar effects on the endotherms with excess water content and on the first endotherm with limite d water content. (C) 1999 Society of Chemical Industry.