Effects of Mesona chinensis Benth polysaccharide on physicochemical and rheological properties of sweet potato starch and its interactions

Polysaccharides are used in starch-based product formulations during processing for improving the final quality of foods. The effects of polysaccharide-starch interactions on the physicochemical and rheological properties of sweet potato starch (SPS)-Mesona chinensis Benth polysaccharide (MCP) gels were investigated. Results showed that MCP can significantly increase the peak viscosity, breakdown and setback viscosity. Rheological determination results suggested that SPS-MCP gels exhibited shear-thinning behavior and that MCP can effectively enhance the viscoelasticity of SPS-MCP gels. Interaction force test indicated hydrogen bonding and electrostatic force can enhance the gel strength and hardness of SPS-MCP gels. Particle size distribution suggested that MCP can enlarge the size of SPS-MCP gels. Fourier-transform infrared spectroscopy (FT-IR) results suggested that the interactions between SPS and MCP involving intermolecular hydrogen bonding and no covalent bonding. In addition, MCP at a suitable concentration can improve the microstructure of SPS-MCP gels. These results facilitate the development of SPS-based products and understand the interaction mechanism between SPS and MCP.