Influence of different galactomannans on the rheological properties and structure of soy protein gel

This research aimed to study the enhancement of the mannose/galactose (M/G) ratio of galactomannan (GM) on the rheological properties and structure of heat-induced gels of soy protein isolate (SPI) under neutral pH conditions. The rheological results showed that the addition of GMs reduced the initial gelation temperature (T gel ) of SPI gels by up to 30.59% (SPI-LBG). Multidimensional rheology revealed that gel properties of SPI gels were significantly enhanced, exhibiting a positive correlation with the M/G ratio of added GM. Based on scanning electron microscopy images, the incorporation of GM promotes the formation of a compact layered microstructure in SPI gels, thereby enhancing yield stress, thixotropy, and structural recovery capacity (LBG > TG > GG > FG). This work provides an analytical framework for protein-polysaccharide gels and a practical strategy for utilizing galactomannans to improve traditional heat-induced protein gel-based foods under neutral conditions.