Abstract: In this paper, perilla seed oil single-layer and double-layer emulsions were prepared using perilla seed oil as the core material and soybean polysaccharides and chitosan as the wall material, respectively. The particle size, zeta potential, physical stability and chemical stability of the emulsions were analyzed. Results showed that with the increase in core-to-wall ratio (m/m), the particle size of single-layer emulsions increased and the physical stability became worse and that the optimum core-wall-ratio was 2:1. With the increase in chitosan concentration, the zeta potential of double-layer emulsions increased gradually, changing from negative and positive values. When the chitosan concentration was 0.2%, the minimum absolute value of zeta potential of 3.6 mV was obtained compared to 43 mV when increasing the chitosan concentration to 0.4%, indicating that the rate of increase in potential slowed with increasing chitosan concentration. Moreover, the particle size decreased first, then increased, and finally decreased again. When the chitosan concentration was 0.2%, the maximum particle size of 5.21 μm was observed, and it decreased to the minimum value of 1.185 μm when increasing the chitosan concentration to 0.4%. The physical stability of emulsions increased with the increase in chitosan concentration, and the chemical stability was significantly influenced by chitosan concentration (p < 0.05). The emulsions with 0.4% chitosan had the highest oxidation stability, followed by those with 0.6% and 0.2% chitosan.

Key words: emulsion, perilla seed oil, soybean polysaccharide, chitosan, stability