A new approach in improving granular cold water swelling starch properties using xanthan gum and β-lactoglobulin/xanthan gum electrostatic coupled gel

Abstract

Granular cold water swelling (GCWS) starches are capable of creating cold-set gels without any heat treatment. However, similar to their thermally gelatinized counterparts, there are some techno-functional challenges related to these physically modified starches. The main objective of this study was to investigate the probable improvement of physical and mucoadhesive properties of alcoholic-alkaline modified GCWS tapioca and corn starches (GCWSTS and GCWSCS, respectively) in the presence of xanthan gum (XG) or β-lactoglobulin-XG electrostatic coupled gel (βlg-XG ECG). Results showed that the viscosity, consistency, pseudo-plasticity, structure recovery, and cold storage stability were improved, and the turbidity development and susceptibility against temperature rise and successive freeze-thaw cycles decreased by increasing the XG to starch ratio from 1:99 to 10:90 in the XG/GCWSTS mixtures, and from 5:95 to 10:90 in XG/GCWSCS mixtures, compared to the respective GCWS starches. The XG to starch ratios of 1:99 and 2.5:97.5 negatively influenced the characteristics of GCWSCS, except for its mucoadhesion. The maximum work of adhesion was obtained at XG to TS ratio of 5:95. Partial substitution of the starch with βlg-XG ECG increased shear-thinning behavior, percent recovery, and work of adhesion, although to a lower degree compared with XG. In contrast, the ECG could substantially reduce the long-term retrogradation and after-five-cycles freeze-thaw syneresis of the GCWS starches much more than XG, despite having a lower concentration. The results of this study suggested that the XG and βlg-XG ECG are capable of extending the applications of GCWS starches in the heat-sensitive functional formulations and 3D printable foods.