Stability of water in oil emulsions using high molecular weight emulsifiers

Excellent stability of water-in-oil emulsions could be obtained by partial crosslinking of the fatty chain in several polyglycerol fatty esters. Such products were capable of emulsifying and stabilizing up to 50 wt% water in vegetable oils at a level of 3-5% emulsifier per total emulsion weight. The corresponding non-crosslinked products require at least 20-25% emulsifier to give the same level of stability, with much higher viscosity. Degree of polymerization, molecular weight distribution, viscosity, dielectric constant and refractive index of the emulsifier were correlated to the emulsion stability. The most remarkable result is a clear correlation between the molecular weight of the emulsifier and emulsion stability; best emulsions were prepared with polymeric emulsifier with MW of Ca. 40000.