Study on oil body emulsion gels stabilized by composited polysaccharides through microgel particles compaction and natural gelation

Oil bodies (OBs), oil storage organelles of oilseeds, are natural, green, and sustainable products that have received much attention in recent years. Different ratios (4:0, 3:1, 2:2, 1:3, 0:4, w/w) of gelatinous polysaccharide κ-carrageenan (κ-Car) mixed with non-gelatinous polysaccharide xanthan (Xan) were used to stabilize OB emulsion gels by microgel particles (MPs) compaction or natural gelation with a total polysaccharide concentration of 0.5 wt%, respectively. Effects of two different treatments of polysaccharides on OB emulsion gels were compared by Fourier transform infrared spectroscopy (FTIR), rheology, and varied microscopy techniques, respectively. For natural gelation, the texture of OB emulsion gels was too rough to be employed in the food system. After compounding κ-Car with Xan, κ-Car and Xan were cross-linked to form a tighter network structure which improved the stability of OB emulsion gels by restricting the movement of OBs and water. Besides, the texture of OB emulsion gels became homogeneous. In addition, MPs compacted closely as micro-units to form a different type of network could benefit to homogeneous texture. The surface area of gels was expanded after microgel treatment, and the hydrogen bond strength enhanced. Unfortunately, the water seepage was more severe after microgel treatment. However, with the increase of Xan proportion before microgel treatment, the instability of OB emulsion gels stabilized by MPs could be improved significantly. This study allowed us to gain a better understanding of tailoring the texture of OB emulsion gels and broadening the application of OBs to low-fat food systems.