Insights into the interaction of CaCl2 and potato starch: Rheological, structural and gel properties

High viscosity of starch greatly limit its application in some specific foods, in this work, a novel low-viscosity potato starch (PS) was developed via crosslinking between PS (3 %, w/v) and Ca2+ to investigate the effect of CaCl2 concentration (0.1-5 % CaCl2, w/v) on the rheological behaviors, structural and gel properties of PS. The results showed that peak viscosity (PV), trough viscosity (TV), final viscosity (FV), and breakdown viscosity (BD) of pasting curves of CaCl2-treated PS were significantly reduced compared with the native PS. The CaCl2 treatment also decreased the firmness of the PS gel and increased its pasting temperature (PT) and gelatinization enthalpy (∆H). Moreover, The CaCl2 treatment also led to more organized crystallites in the PS granules as affected by the slight increase in the ratio of 1044/1015 cm-1 in the FT-IR analysis, reduced the homogeneity of ordered structures inside granules as indicated by the increase in conclusion temperature (Tc)-onset temperature (To) in DSC analysis, and decreased relatively crystallinity revealed by XRD analysis. The findings of this study indicated CaCl2-treated PS could serve as food ingredients with reduced paste viscosity and regulated paste stability under shear during heating.