Effect of modified Acacia gum (SUPER GUM™) on the stabilization of coconut o/w emulsions

Two modified Acacia gums, the already tested SUPER GUM™ EM2 and the new EM10, were used as combined emulsifiers and stabilizers in coconut oil model emulsions. The properties of gum solutions as well as those of the emulsions were examined. The gum solutions were completely mechanically stable during high-pressure homogenization; therefore, the gum could be added to the emulsion prior to high-pressure treatment. The emulsions were prepared by a small-scale rotor-stator process and by high-pressure homogenization, respectively. Droplet size, stability and rheological properties of the emulsions were examined. As expected, the high-pressure process was very effective. The emulsions made with both modified gums had a droplet size below 1 μm and were completely stable for at least 7 weeks at up to 30 °C. The new SUPER GUM™ EM10 was more efficient as an emulsifier than EM2; the droplet size distribution was more homogenous. All emulsions proved to be low-viscous and nearly Newtonian liquids. It can be concluded that the emulsion stability was mainly a result of the excellent emulsifying properties and not of an additional thickening effect of the gums. The modified Acacia gums can be recommended as an emulsifier and stabilizer for application in different food products, preferably in low-viscous emulsions such as coconut milk drinks or other beverages.

Influence of the number of cycles on the particle size distribution of 8 wt% SUPER GUM™ emulsions prepared by high-pressure homogenization. (a) EM2; (b) EM10; C0–C2 = number of homogenization cycles.Figure optionsDownload as PowerPoint slide