Influence of formulation parameters on lipid oxidative stability of Pickering emulsion stabilized by hydrophobically modified starch particles

Sunflower oil-in-water Pickering emulsions were fabricated using octenyl succinic anhydride modified rice starches as particulate stabilizers. The major factors influencing oxidative stability of emulsions were investigated. Results indicated that oxidative stability was enhanced with the increase of starch particle concentration and oil fractions. The emulsions had excellent oxidative stability at pH 6.0-7.0. Low NaCl concentration of 40 mmol/L slightly increased lipid stability, while high NaCl concentration decreased oxidative stability. Sucrose concentrations ranging from 0 to 200 mmol/L had no obvious effect on oxidative stability. Results of confocal laser scanning microscope showed that the hydrophobically modified starch particles built up 3D-network barrier around oil droplets at oil-water interface, which increased the viscosity of continuous phase and prevented oil droplets from contacting with pro-oxidants in water phase, thus decreasing peroxide value and thiobarbituric acid reactive substances. These results implied that starch-based Pickering emulsion may be a promising delivery vehicle for bioactive compounds.