Utilization of layer-by-layer interfacial deposition technique to improve freeze-thaw stability of oil-in-water emulsions

The freeze-thaw stability of 5 wt% hydrogenated palm oil-in-water emulsions (pH 3) containing droplets stabilized by sodium dodecyl sulfate (SDS)-chitosan-pectin membranes was studied. The multilayered interfacial membranes were created using an electrostatic layer-by-layer deposition method. The zeta-potential, mean particle diameter, fat destabilization, apparent viscosity and microstructure of the emulsions were used to examine the influence of freezing on their stability. Emulsions containing oil droplets stabilized only by SDS were highly unstable to droplet coalescence when either the oil phase became partially crystallized or the water phase crystallized. Emulsions containing oil droplets stabilized by SDS-chitosan membranes were stable to droplet coalescence, but unstable to droplet flocculation. Emulsions containing droplets stabilized by SDS-chitosan-pectin membranes were stable to both droplet coalescence and flocculation. The interfacial engineering technology utilized in this study could lead to the creation of food emulsions with improved stability to freeze-thaw cycling. (c) 2006 Elsevier Ltd. All rights reserved.