Study on inhibition effects and mechanism of wheat starch retrogradation by polyols

摘要

Effects and mechanism of polyols (mannitol, isomalt or xylitol) on the retrogradation of wheat starch (WS) were investigated by rapid viscosity analysis (RVA), rheological properties, fourier-transform infrared spectroscopy (FTIR), low-field nuclear magnetic resonance (LF-NMR), texture profile analysis (TPA), differential scanning calorimetry (DSC) and X-ray diffraction (XRD) in this study. A decrease in peak viscosity, trough viscosity, breakdown, final viscosity and setback of WS was observed with addition of polyols. The storage modulus (G ') and the change rate of G ' in the presence of polyols were significantly reduced. The number of hydrogen bonds increased accordingly and polyols in starch gel could combine with more water and reduce water migration. After 4 weeks storage at 4 degrees C, the hardness, retrogradation enthalpies (oH), crystallization rate constant (k) and relative crystallinity (RC) of WS/polyols were significantly reduced compared with those of the blank. Hence, polyol was promising to be a useful additive to inhibit the retrogradation of wheat starch, which provided a reference for inhibiting the retrogradation of starch-containing food.