Effect of amylose on pasting and rheological properties of corn starch/xanthan blends

摘要

In this study, the pasting and rheological properties of gels obtained by mixing xanthan gum with (XG) waxy corn starch (WCS), normal corn starch (NCS), and high-amylose corn starch (HACS) were evaluated. The degrees of interaction with XG differed significantly among the various starch preparations. Rapid visco-analysis showed that XG affected the peak viscosities of NCS paste more significantly than those of WCS paste. The setback viscosity and pasting temperature of the WCS/XG mixtures were higher than that of WCS samples for the phase separation. However, adding XG to NCS lowered its setback viscosity and pasting temperature. All paste samples exhibited weak gel-like behaviors, and their rigidities decreased after XG addition. Time sweep and texture analysis data demonstrated that XG inhibited the amylose retrogradation upon interaction with amylose. These results suggested that the effects of XG on starch pasting and rheological properties were enhanced with increasing amylose content of starch, which can be attributed to the interactions between XG and amylose molecules.