Assessment of pea pod polysaccharides effect on stability and flow behavior of oil-in-water emulsion

In this study, the stability of oil-in-water emulsion systems prepared with different concentrations of pea pod polysaccharides (0.5-4.5% w/w) were evaluated within 30 days at 25 ºC in comparison with Arabic gum. For this purpose, emulsion properties such as droplet diameter, span value, rheological properties and its microstructure were studied. With increasing pea pod polysaccharides and Arabic gum concentration from 0.5 to 4.5%, the droplet diameter was decreased from 2899.2 to 1432.4 nm and from 3415.5 to 1385.6 nm, respectively. The results indicate the ability of pea pod polysaccharides for suitable coating of droplets in dispersed phase compared to Arabic gum. The droplet diameter was increased from 1384.5 to 2933.1 nm for pea pod polysaccharides and from 1637.3 to 2699.2 nm for Arabic gum during storage time. The creaming index decreased by increasing the concentration of Arabic gum and pea pod polysaccharides from 64.42 to 4.67 % and from 48.09 to 10.81%, respectively. On the other hand, the creaming index was increased with increasing storage time. Evaluation of -flow behavior indicated the non-Newtonian and shear thinning behavior of emulsion systems containing Arabic gum and pea pod polysaccharides. With increasing the concentration of pea pod polysaccharides and Arabic gum, apparent viscosity of fresh emulsions were increased from 28.45 to 40.44 mPa.s and from 27.35 to 53.70 mPa.s, respectively. Decrease in apparent viscosity was observed with increase of storage. Finally, the results indicated the relatively good ability of pea pod polysaccharides to increase stability of oil in water emulsion through increasing the viscosity of continuous phase of emulsion system.