Construction and characterisation of xanthan gum/ sodium alginate-wheat gliadin core-shell structured hydrogel sphere

Abstract

This study prepared a core-shell structured hydrogel bead using xanthan gum (XG)/sodium alginate (SA)-wheat gliadin (WG), and investigated the interactions between different components. The rheological properties revealed that the viscosity of the gel solutions increased with the increase in XG/SA ratio, exhibiting a weak gel-like viscoelastic behavior. The successful attachment of WG to the hydrogel bead surface was proven by zeta potential and confocal laser scanning microscopy (CLSM) in a pH 4 environment. It was observed on a Scanning Electron Microscope(SEM) that all hydrogel beads formed a three-dimensional mesh structure. Water content is between 92 % and 98 %. In addition, magnetic resonance imaging showed that XG/SA-WG (XG/SA∗), which was the ratio of 1:4, could be loaded with more water. As the proportion of SA increased, the hardness of the hydrogel beads increased from 57.11 g to 171.25 g, and the Cohesiveness increased from 0.34 % to 0.52 %. Meanwhile, the hydrogel beads demonstrated good pH responsiveness, as shown by the solubility of the hydrogel beads in different pH levels. Differential scanning calorimetry (DSC) demonstrated the ability of polysaccharides to improve the thermal stability of WG. Fourier infrared spectroscopy (FTIR) revealed that electrostatic interactions and hydrogen bonding dominate the interactions between the different components of the hydrogel beads. This research presents valuable views and a theoretical foundation for the future development of other core-shell structures and the delivery of active substances.