Effect of Pregelatinization and Retrogradation on Some Physicochemical Changes of Wheat-Potato Starches

Abstract

The freezable (FW) and unfreezable water (UFW) contents of wheat and potato starches and their physically modifiedforms [pregelatinized (PGS) and retrograded (RS)] were analyzed by Differential Scanning Calorimetry (DSC) atvarious hydration levels (25, 35, 45, 55, 65, 75 and 85%). In all the starch samples, the UFW content increased withincreasing hydration level. Potato starch samples (native, pregelatinized and retrograded) had higher UFW contents thanwheat starch samples at all hydration levels. Similarly, with the increase of hydration level in all starch samples, onset(To), peak (Tp) and endset (Te) temperatures of the peaks also increased. It was obtained that physical modifications instarches had significant effects (P