The roles of soy soluble polysaccharide on the emulsion stability against stimulated gastric conditions and food complexes - a review

Oil-in-water emulsions can be stabilized by proteins, and is widely used for delivery of hydrophobic bioactive compounds in food and pharmaceutical applications. But emulsions stabilized by proteins such as whey protein or soy protein isolates (SPI) may lose their stability under gastric conditions due to changes of temperature, pH and the presence of digestive enzymes. However, the additions of soy soluble polysaccharide (SSP) to protein-stabilized emulsions are reported to improve the stability against low pH, thermal treatment and under-simulated gastric conditions. This review emphasizes the importance of incorporating of SSP into SPI stabilized-emulsions and dispersion and encapsulated products to improve the stability against low pH, thermal treatment and stimulated peptic and tryptic digestions. The mechanism responsible for the stabilization of the SPI emulsion by SSP at acidic pH can be due to a balance between electrostatic interactions of SSP with SPI and interfacial adsorption of SSP.