Inhibition of Droplet Growth in Model Beverage Emulsions Stabilized Using Poly (ethylene glycol) Alkyl Ether Surfactants Having Various Hydrophilic Head Sizes: Impact of Ester Gum

The effect of ester gum, a widely used weighting agent, on Ostwald ripening in model beverage emulsions formulated using different food-grade surfactants was examined. A microfluidizer was used to prepare 5% orange oil-in-water emulsions stabilized by a series of ethylene glycol alkyl ether surfactants. Emulsions prepared using only orange oil exhibited an appreciable increase in droplet size during a 14-day storage, independent of surfactant type or concentration. Incorporation of ester gum into the oil phase of the emulsions effectively inhibited droplet growth at concentrations ≥20%. The inhibition of droplet growth by ester gum depended on the surfactant type (hydrophilic group size) and concentration. Overall, ester gum stabilized the emulsions by acting as an Ostwald ripening inhibitor, as well as a weighting agent.