Preparation and Characterization of Nano-sized Emulsions Produced from Acid-soluble Soy Protein and Polysaccharide Complexes

Abstract:

Due to its superior stability during storage, against aggregation and creaming, nano-sized emulsion is an effective method to improve the bioavailability and solubility of fat-soluble substances. The preparation process of nano-sized emulsion produced from acid-soluble soy protein (ASSP) and soluble soy polysaccharide (SSP) complex were investigated, the effect of changes in pH, oil content, pressure, ASSP to SSP ratio, and temperature on the formation and stability of the resulting emulsions were also analyzed. The results showed that a stable emulsion (i.e. having a mean droplet size of 269.33 ± 2.26 nm) was obtained with 400 bar pressure, pH between 3.0 and 4.0, ASSP to SSP ratio of 1:4, and 5% to 20% oil content; the average droplet size of the resulting emulsion did not change significantly (p > 0.05) after 60 days. In addition, pH values, high pressure, and heat treatment had a significant effect on the emulsion stability (p < 0.05); emulsion prepared from ASSP and SSP complex can be used in acidic medium, high temperature, and high salt concentration in the food industry. Furthermore, the morphology of the emulsion produced from ASSP and SSP complex was also studied through the addition of pectinase. As the complex was well fixed on the surface of the emulsion droplets, the emulsions exhibited excellent long-term stability and dispersion property.