Development and characterization of structured water-in-oil emulsions with ethyl cellulose oleogels

The food industry confronts an enormous challenge to develop stable margarine-type water-in-vegetable oi l (W/ O) emulsion-based table spreads with reduced concentration of saturated f a t and without trans fats. In the present work, we developed a gelled W/O emulsion (Gelled-W/O-E) containing 20% of water using a mixture of a conventional W/O emulsion (W/O-E) stabilized with glycerol monostearate (GMS), and an ethyl cellulose (EC) oleogel. The mechanical , microstructure and stability of the resulting gelled emulsion (Gelled-W/O-E) was compared with control systems consisting of conventional W/O emulsions (W/O-E) and EC-GMS oleogels (EC-GMS-O; no water added) formulated using the same GMS (0.5% and 1.0%) and EC (7%) concentration as in the Gelled-W/O-E. The Gelled-W/O-E showed higher elasticity and emulsion stability in comparison with the control systems. This in spite the EC and GMS concentrations used were below the minimal concentration required to develop a gel , and the tentatively lower solid content in the Gelled-W/O-E than in the EC-GMS-O because the presence of water. We observed that by increasing the GMS concentration in the Gelled-W/O-E, the water droplet size decreased as gel elasticity and W/O emulsion stability significantly increased. We associated this behavior to a synergistic GMS-EC interaction that kept the GMS at the water-oi l droplet interface. These results showed the role of water droplets as active fillers in determining the rheological properties of the Gelled-W/O-E , and that the GMS efficiency as emulsifier increased in the presence of EC in the oi l phase. After comparing the microstructural properties of commercial margarine spreads with those of the Gelled-W/O-E, we concluded that the structured W/O emulsion is a novel way to achieve similar functionality to margarine spreads, without the use of saturated and trans-fats.

Automated summary

The study developed a gelled W/O emulsion with 20% water content, showing higher elasticity and stability compared to traditional emulsions, indicating the active role of water droplets in determining rheological properties.