Effects of Crosslinked Sugar Beet Pectin on the Pasting, Rheological, and Structural Behaviors of Corn Starch

The present study was conducted to investigate the impact of crosslinked sugar beet pectin (CLSBP) with varying crosslinking densities on the pasting, rheological, and structural behaviors of corn starch (CS). The results indicated that the pasting temperature of CS gradually decreased, whereas the peak, final, and setback viscosities increased with an increase in the crosslinking density. The presence of CLSBP increased the swelling power of CS-CLSBP mixtures, while reduced the syneresis. The rheological tests suggested that all CS-CLSBP mixtures were typical non-Newtonian fluids and CLSBP could effectively enhance the viscoelasticity. Furthermore, the particle size distribution demonstrated that CLSBP facilitated the swelling of CS granules. Fourier-transform infrared spectroscopy results demonstrated that CLSBP addition delayed the rearrangement of starch molecules. The low-field nuclear magnetic resonance experiment suggested that CLSBP inhibited the movement of water molecules of CS-CLSBP gels. In addition, scanning electron microscopy suggested that CLSBP with higher crosslinking density produced a more compact CS-CLSBP gel microstructure with smaller pore sizes. These finding revealed that CLSBP crosslinking density markedly modulated the pasting, rheological, and structural attributes of the CS-CLSBP mixtures, owing to the strong intermolecular associations between CS and CLSBP.