Effects of particle size distribution of potato starch granules on rheological properties of model dough underwent multiple freezing-thawing cycles

In order to elucidate the mechanism underlying the effect of different-sizes potato starch on dough during freeze-thaw treatment, the rheological properties, moisture distribution, secondary structure, and relative crystallinity of dough were investigated. The results showed that the storage modulus (G '), loss modulus (G ''), and complex modulus (|G*|) of dough increased as a result of the freeze-thaw treatment, and the effect was more obvious as the starch granular sizes increased. The higher beta-sheet and T(22 )contents reflected the higher viscoelasticity and freeze-thaw sensitivity, which may be related to the higher degree expansion of amylose. In contrast, dough with small-sized starch had higher intermolecular interactions, and denser structure, lower water migration, showing that this has better resistance and higher stability. The presented mechanisms may contribute to the better understanding of the effects of freeze-thaw process on model dough properties.