Homogenized soybean hull suspension as an emulsifier for oil/water emulsions: Synergistic effect of the insoluble fiber and soluble polysaccharide

In this study, the functional properties of the soybean hull soluble fractions and insoluble fiber in stabilizing oil-in-water emulsions were investigated by changing the soluble fraction (SF) content in the soybean hull suspensions. High-pressure homogenization (HPH) caused the release of soluble materials (Polysaccharides and proteins) and the deagglomeration of insoluble fibers (IF) from soybean hulls. The apparent viscosity of the soybean hull fiber suspension increased as the SF content of the suspension increased; The absolute value of ζ-potential increased from 18 to 28 mV. In addition, the IF individually stabilized emulsion had the largest emulsion particle size (32.10 μm), but decreased as the SF content in the suspension increased to 10.53 μm. The microstructure of the emulsions showed that surface-active SF adsorbed at the oil-water interface formed an interfacial film, and microfibrils in IF formed a three-dimensional network in the aqueous phase, which synergistically stabilized the oil-in-water emulsion. The findings of this study are important for understanding emulsion systems stabilized by agricultural by-products.