Stabilization and delivery performance of soybean oil body emulsions: the role of chitosan, guar gum, and ι-carrageenan in polysaccharide-based systems

This study constructed various polysaccharide-soybean oil body complex emulsions and investigated their delivery efficacy for β-carotene. Soybean oil body emulsions (USOB) were prepared via high-shear and ultrasound treatments, with three polysaccharides (chitosan, guar gum, and ι-carrageenan) added to enhance emulsion stability under acidic conditions (pH 3.0 and 5.0). Polysaccharides with different charge characteristics result in distinct particle size and zeta potential for the complex emulsion at pH 3 and pH 5. The incorporation of polysaccharides improved the rheological properties of the emulsion, indicated by increased apparent viscosity, storage modulus, and loss modulus. At pH 3, carrageenan elevated interfacial protein content from 69.29% to 93.48%. At pH 5, chitosan significantly increased interfacial protein content from 81.40% to 92.89% (p < 0.05). Additionally, polysaccharides induce structure changes in interfacial proteins, and surface hydrophobicity decreases. Polysaccharides improve the environmental stability of USOB, but guar gum-oil body complex emulsions are susceptible to the influence of salt ions and temperature. Polysaccharides significantly improved the encapsulation efficiency of β-carotene in emulsions under acidic conditions, particularly at pH 5 (p < 0.05). In vitro digestion indicated that polysaccharides inhibit the digestion of USOB in the gastrointestinal tract by forming interfacial barriers, thereby enhancing the bioavailability of β-carotene (p < 0.05). In summary, the polysaccharide-soybean oil body complex emulsion demonstrates significant potential for delivering lipophilic substances such as β-carotene.