Effect of Two Different Polysaccharides on the Stability of Emulsion Formed by Rapeseed Oil Bodies

In order to improve the stability of emulsions of rapeseed oil bodies under different environmental conditions. The soluble soybean polysaccharide (SSPS) with negative electric charge and konjac glucomannan (KGM) without electric charge were used to form the emulsions of rapeseed oil bodies. Laser scattering particle analyzer and microscope were used to analyze the particle size and observe the microstructure of rapeseed oil body emulsions. The stability of emulsions of rapeseed oil bodies with two different polysaccharides under different environment stresses (pH, salt concentrations and heat treatments) was investigated, and the emulsions of rapeseed oil bodies without polysaccharide were used as control. The results of experiment showed that the particle of emulsions of rapeseed oil bodies decreased along with the increase of SSPS and KGM concentrations. In addition to pH2.0, the particle size of emulsions of rapeseed oil bodies without polysaccharide at different pH was significantly higher (P<0.05) than that of the emulsions of rapeseed oil bodies with SSPS and KGM. In addition to pH10.0, the particle size of emulsions of rapeseed oil bodies with SSPS was significantly lower (P<0.05) than that of the emulsions of rapeseed oil bodies with KGM. Nevertheless, the pH values caused no effect on the particle size of emulsions of rapeseed oil bodies with SSPS. Although there was no significant changes (P>0.05) for the particle size of emulsions of rapeseed oil bodies without polysaccharide at different salt concentrations, the particle size was significantly higher (P<0.05) than the emulsions of rapeseed oil bodies with SSPS and KGM. The microstructure observation also showed that the oil droplets of emulsions of rapeseed oil bodies with SSPS and KGM had better dispersivity than that of emulsions of rapeseed oil bodies without polysaccharide. The particle size of emulsions of rapeseed oil bodies without polysaccharide increased along with the increase of temperatures, which was significantly higher (P<0.05) than that of the emulsions of rapeseed oil bodies with KGM and SSPS, the temperature changes showed there was no significantly effect (P>0.05) on the particle size of emulsions of rapeseed oil bodies with SSPS. Comprehensive above results, KGM and SSPS can significantly improve the stability of the emulsions of rapeseed oil bodies, SSPS shows a better effect.