Influence of Alyssum homolocarpum seed gum on the stability and flow properties of O/W emulsion prepared by high intensity ultrasound

This study introduces Alyssum homolocarpum seed gum, as a natural stabilizer for O/W emulsions. The droplets characteristics, flow properties and physical stability of ultrasonically prepared corn oil-in-water emulsions were investigated at various gum concentrations. The results indicated that for the freshly prepared emulsions, the mean diameter of droplets decreased significantly with an increase in gum concentration from 0.25% to 0.75%. Storage of emulsions for a period of 4 weeks resulted in an increase in the size of droplets, being substantially greater for the samples containing 0.25 and 0.5% gum and negligible for those prepared with 0.75 and 1.0% gum. Similar trend was observed for the specific surface area of droplets but in the opposite direction. Optical microscopy demonstrated that increasing the proportion of gum up to 0.75% reduced the extent of flocculation and coalescence and enhanced monodispersity. Newtonian and non-Newtonian shear-thinning flow behaviors were observed for emulsions prepared with 0.25% gum concentration and those containing higher concentrations respectively. Accordingly, faster creaming was found to be associated with the emulsions prepared with low gum concentration.