Changes in Physicochemical Properties of Maize Starch Supplemented with Xanthan Gum and Fatty Acids
Article
Figures
Metrics
Preview PDF
Reference
Related
Cited by
Materials
Abstract:
To improve the processing characteristics and product quality of maize starch (MS), the effects of the combinations of xanthan gum (XG) and three types of fatty acids with different chain lengths (myristic acid (MA), palmitic acid (PA), and stearic acid (SA)) on the pasting properties, rheological properties, gelling properties, thermal properties, and gel microstructure of MS were investigated. Rapid Visco Analysis (RVA) results showed that the peak viscosity and the final viscosity of MS paste supplemented with the XG-PA and XG-SA combinations increased by 123 to 131 mPa·s and 64 to 94 mPa·s, respectively, and the setback values were reduced by 16 to 18 mPa·s. By contrast, the viscosity of MS paste supplemented with the XG-MA combination was reduced, and the setback value increased. Static rheological test results show that MS supplemented with the combinations of XG and the three types of fatty acids with different chain lengths exhibited non-Newtonian shear thinning behavior (rheological behavior index n < 1). Dynamic rheological test results showed that the storage modulus G′ and loss modulus G″ of MS supplemented with the XG-PA and XG-SA combinations increased, indicating that adding these two combinations can improve the viscoelasticity of MS; however, the G′ and G″ values of MS supplemented with the XG-MA combination decreased. The gel hardness of MS supplemented with the combinations of XG and the three types of fatty acids with different chain lengths was reduced by 65 to 77 g. Differential scanning calorimetry (DSC) results showed an endothermic peak at 89 to 110 ℃, indicating the formation of amylose-fatty acid complexes in MS with the combinations of XG and fatty acids. Scanning electron microscopy (SEM) results showed that the MS gel network structure had become more fractured and showed a lot of fragmented structures, indicating that the gel structure of MS supplemented with the combinations of XG and fatty acids was weakened.
