Effect of Krasch polysaccharide on the gelatinization and retrogradation of wheat starch.

The effect of Krasch polysaccharide (ASKP) on the gelatinization and retrogradation of wheat starch (WS) was studied. RVA results displayed that ASKP addition increased the setback values of WS, which indicated that ASKP might promote the short-term retrogradation of WS. DSC and XRD results demonstrated that the retrogradation percentage of WS during long-time storage significantly decreased with the addition of ASKP, suggesting the inhibition effect of ASKP on the long-term retrogradation of WS. As shown in TPA test, ASKP addition increased the hardness of starch gel at the beginning but decreased it after 14 days' storage. Results of FT-IR revealed that ASKP could promote the water retention and intermolecular hydrogen bonding formation. With the addition of ASKP, the spin-spin relaxation time measured by LF-NMR decreased from 358.47 ms to 274.15 ms, illustrating that the WS paste containing ASKP had higher water retention ability. Leached amylose content results manifested the interaction between WS and ASKP. In summary, ASKP has potential to be a modifier on the retrogradation of starch in food processing.