Physical properties of oil-in-water emulsions as a function of oil and soy soluble polysaccharide types

Soy soluble polysaccharide (SSPS), extracted from the by-product of soy protein isolation, has been widely established as an emulsifier for oil-in-water (O/W) emulsions. Impact of the type of SSPS (i.e. SSPS-L; SSPS-M; and SSPS-H differentiated by their respective extraction conditions) and the type of oil (i.e. Perilla seed oil – PSO; palm kernel oil – PKO; and n-Hexadecane) was examined through analysis of the differences in average droplet diameter, droplet size distribution (DSD) and emulsion rheological properties. Oil/water interfacial tension strongly depended on SSPS type. SSPS-L was the most capable in reducing interfacial tension against PSO, PKO and hexadecane followed by SSPS-M and lastly SSPS-H. Irrespective of oil type, at 20% oil content, SSPS-L and M were better emulsifiers for achieving small droplets due to their high protein content. Both SSPS (types L and M) solutions and their respective emulsions regardless of oil type exhibit Newtonian flow behavior while SSPS-H solution and the respective emulsions show shear-thinning behavior. Emulsion viscosity was influenced by both SSPS and oil types with SSPS-H and hexadecane producing high viscosity emulsions. This paper provides important information on the performance of different types of SSPS against different types of oils which can be used in formulating food and beverage systems.