Gelatinization of starch characterized using modulated temperature differential scanning calorimetry

Starches with varying amylose content, one hydroxypropylated high amylose starch and two thermoplastic starches (pre-gelatinized and with V-type crystals) were gelatinized in the presence of added water. Gelatinization was characterized using modulated temperature differential scanning calorimetry (mT-DSC) with a heat-cool temperature profile. The gelatinization endotherms were recorded in the total heat capacity curve that were resolved into storage (reversing) and loss heat capacities, and non-reversing heat capacity curve. The endotherms were mainly of non-reversing nature, with a small contribution from the reversing component. Starch melting is a plasticizer assisted disruption of crystals and other structures such as starch-lipid complexes and granules. Reversibilty was limited since the native amylopectin crystals are rarely re-crystallized and starch-lipid complexes do not reform, and any re-crystallization is due to subsequent slow formation of amylose crystals.