Effect of gellan gum on the rheology, gelling, and structural properties of thermally induced pea protein isolate gel

The improvement of heat-induced pea protein isolate (PPI) gel with weak gel properties has attracted research interest in recent years. In this study, gellan gum (GG) was used to regulate the rheology, gelling, and structural properties of PPI gel. The related properties of GG-PPI gels were significantly improved by the addition of GG, including gel strength, water holding capacity, and rheological properties. GG also slightly decreased the surface hydrophobicity of the PPI gel, but it was still higher than that of pure PPI without heat treatment. The zeta potential of GG-PPI composite gels increased from 27.2 to 30.0 with the addition of GG, and the turbidity increased from 0.42 to 0.52 accordingly. The crystal diffraction peaks of GG disappeared after forming the composite gels between GG and PPI, indicating that there might be interactions between GG and PPI. Scanning electron microscopy revealed that the presence of GG promoted the formation of a dense and homogeneous gel network structure. In conclusion, GG effectively improved the gel properties of PPI, which can provide some fundamental basis for the potential applications of PPI.