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

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 beta-lactoglobulin-XG electrostatic coupled gel (beta lg-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 beta lg-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 beta lg-XG ECG are capable of extending the applications of GCWS starches in the heat-sensitive functional formulations and 3D printable foods.

Automated summary

Increasing the ratio of XG to starch can improve the physical and mucoadhesive properties of GCWS starches. Partial substitution of starch with beta lg-XG ECG can enhance certain properties to a lesser degree.