Study on the retrogradation behavior of starch by asymmetrical flow field-flow fractionation coupled with multiple detectors.

In this study, the capacity of asymmetrical flow field-flow fractionation (AF4) coupled with multiangle light scattering (MALS) and differential refractive index (dRI) detectors, to monitor starch retrogradation behavior in situ was evaluated. Meanwhile, the starch samples were characterized by differential scanning calorimetry (DSC) and fourier transform infrared spectroscopy (FTIR). The effect of the botanical origin, amylose/amylopectin ratio, storage conditions (i.e., temperature and time), and salt on starch retrogradation was systematically investigated. The starch aggregation and disassociation is a kinetic equilibrium process that is dependent on the storage conditions and the content of amylose. Moreover, it was found that nitrate ions retarded starch retrogradation behavior by inhibiting the formation of hydrogen bonds between amylose molecules. The results suggest that the formation of the small amylose aggregates plays an important role in starch retrogradation and maize amylopectin degradation. The information obtained by AF4-MALS-dRI is valuable for understanding the starch retrogradation mechanism.