Characterization of thermal properties of potato dry matter-water and starch-water systems

Potato dry matter samples of varying moisture contents were analyzed by differential scanning calorimetry (DSC). One endothermic and one exothermic transition were observed when the moisture content was <50% (w/w) in the dry matter-water system. Both endothermic and exothermic transitions of potato dry matter were influenced by moisture content. One endothermic transition at about 66°C was observed when the samples were reheated after 2 wk of storage at 5°C. Gelatinization and retrogradation of starch are chiefly responsible for the endothermic transitions in the potato dry matter. The exothermic transition may originate from chemical reactions such as Maillard and caramelization during heating of a potato dry matter-water system when water is limited (<50%, w/w) and at temperatures >120degreesC.