Abstract: In order to study the effects of mixing ratio and interaction between oleosin protein (OL) and phosphatidyl choline (PC) on the stability of reconstituted oil emulsion, we determined the emulsification properties, fluorescence spectra, dynamic laser scattering patterns, turbidity, contact angle and storage stability of different samples. We observed the droplet size distribution and microstructure changes in emulsions by optical microscopy. The results showed that the particle size distribution of the emulsion was uniform, and the best emulsification properties were obtained (EAI = 33.11 m2/g, ESI = 74.22 min) with a ratio of OL/PC of 1.5. At the same time, the emulsion exhibited the best surface tension and storage stability. The fluorescence spectral analysis showed that OL was most closely combined with PC. But with the increase of OL concentration, competitive adsorption of OL with PC occurred at the oil-water interface, and as a result, the emulsifying ability and emulsion stability were both reduced, and irregular spherical droplets were observed by optical microscopy. The results showed that the optimum ratio of OL to PC was 1.5 for preparing reconstituted oil emulsion, which could promote the interaction between OL and PC and enhance the stability of the emulsion.

Key words: reconstituted oil emulsion; oleosin; phosphatidyl choline; stability; interfacial properties