Stabilization of liquid water‐in‐oil emulsions by modifying the interfacial interaction of glycerol monooleate with aqueous phase ingredients

Glycerol monooleate (GMO)-stabilized liquid water-in-vegetable oil (W/VO) emulsions are difficult to stabilize due to the desorption of GMO from the W-VO interface towards the oil phase. This work improved the stability of GMO-stabilized liquid 20 wt% water-in-canola oil (W/CO) emulsion by modifying the dispersed aqueous phase composition with hydrogen bondforming agents. As a control, 20 wt% water-in-mineral oil (W/MO) emulsion was also utilized. Different concentrations of hydrogen bond-forming agents (citric acid (CA), ascorbic acid (AA), low methoxyl pectin (LMP)) with and without salts (sodium chloride (S) or calcium chloride (Ca)) was added to the aqueous phase before emulsification, which enhanced emulsifier binding to the water-oil interface. The emulsions were characterized by phase separation, stability against accelerated gravitation, microstructure and rheology. W/CO emulsion without any aqueous phase additive destabilized instantly, whereas W/MO emulsion stayed stable. The addition of hydrogen bond-forming agents and salts significantly improved emulsion stability. LMP, with many hydrogen bond-forming groups, was able to provide the highest emulsion stability after 7 days in both oils compared to AA, CA and their mixtures with S. Emulsions with both oils formed weak gels with viscous and elastic characteristics due to the formation of an extensive network of water droplet aggregates. Overall, the hydrogen bond-forming agents interacted with GMO at the interface, thereby improving their presence at the water droplet surface, allowing significantly improved stability of GMO-stabilized liquid W/CO emulsions. The knowledge developed in this research can be useful in applying GMO in stabilizing liquid water-in-oil emulsion without using any crystal network. Stabilization of liquid water-in-oil emulsions by modifying the interfacial interaction ofglycerol monooleate with aqueous phase ingredients Maria Romero-Peña, Supratim Ghosh Department of Food and Bioproduct Sciences, College of Agriculture and Bioresources, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5A8, Canada Escuela Superior Politécnica del Litoral, ESPOL, Facultad de Ingenieŕıa en Mecánica y Ciencias de la Producción, Campus Gustavo Galindo Km. 30.5 Vı́a Perimetral, P.O. Box 09-01-5863, Guayaquil, Ecuador *Corresponding authors contact E-mail: supratim.ghosh@usask.ca

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