Fabrication of β-conglycinin-stabilized nanoemulsions via ultrasound process and influence of SDS and PEG 10000 co-emulsifiers on the physicochemical properties of nanoemulsions

Nanoemulsions stabilized by beta-conglycinin (7S),beta-conglycinin/sodium dodecyl sulfate (SDS) and beta-conglycinin/polyethylene glycol 10000 (PEG 10000) were produced via ultrasound process. All the nanoemulsions showed the desired mean particle size and narrow size distribution. The effects of pH, ionic strength and temperature on the properties of the nanoemulsions were investigated, and the long-term stability of the fabricated nanoemulsions was also monitored during storage at 4 degrees C. The nanoemulsions prepared by 7S exhibited a good stability over various pH (< 4 or > 5), ionic strength (0-500 mM NaCI), thermal treatment (80 degrees C) and storage time (0-45 days). The stability of 7S nanoemulsions was enhanced by adding SDS, whereas reduced by adding PEG 10000, which could be attributed to the higher zeta-potential in the present of SDS leading to stronger electrostatic repulsion against droplet flocculation, whereas opposite was observed for the addition of PEG 10000. Therefore, this study provided important evidences for the fabrication of nanoemulsions using protein/surfactant complexes as the emulsion stabilizer via ultrasound process.