Effect of flax gum on the functional properties of soy protein isolate emulsion gel

Abstract Soybean oil emulsion gel is often used to replace part of fat, thereby the content of saturated fatty acids was reduced in food. This paper studied the effect of flax gum (FG) on the rheological properties, thermal properties, microstructure, and gel properties of soy protein isolate (SPI) acid-induced emulsion gels. The results showed that the apparent viscosity of SPI emulsion increased with the increase of FG addition. The mechanical properties, frequency dependence and deformation resistance of the SPI emulsion gel can be significantly improved by adding an appropriate amount of FG (0.6%). The chemical stability of the protein was significantly enhanced, the thermal stability of the emulsion gel was improved, and the water retention rate of the emulsion gel was increased by adding a certain amount of FG. The study also found that the pores between the protein network were increased and the fractal dimension of the gel system (2.862–2.775) was reduced by adding FG. When the FG concentration was 0.8%, the complexity of the gel system was minimal. In summary, FG was found to play an important role in improving the properties of Emulsion Gel, enhancing thermal stability and enhancing the strength of the gel network structure in the soy protein isolate-FG gel system.