Hydrophobically modified ethyl(hydroxyethyl)cellulose as stabilizer and emulsifying agent in macroemulsions

Stability, droplet diameter and viscosity of o/w macroemulsions of olive oil stabilized with lecithin from soybean and different types of polymers have been investigated. The stabilizing polymers were non-ionic cellulose ethers, both with and without hydrophobic groups grafted onto the polymer backbone. Emulsions without polymers showed essentially no stability against creaming. Unmodified polymers provided limited stability, while hydrophobically modified versions of the polymers improved the stability dramatically. The viscosity of emulsions stabilized by hydrophobically modified polymers was significantly increased compared with aqueous solutions of the polymers alone, suggesting network formation including both polymers and emulsion droplets. It was also found that dilution had virtually no effect on the droplet diameters of emulsions stabilized with hydrophobically modified cellulose ethers and that coalescence was effectively opposed. (c) 2005 Elsevier B.V. All rights reserved.