  We found experimentally that the elasticity of sunflower oil-in-water
emulsions (SFO-in-W) stabilized by Yucca Schidigera Roezl saponin extract, is
by more than 50 times higher as compared to the elasticity of common emulsions.
We revealed that strong specific interactions between the phytosterols from the
non-purified oil and the saponins from the Yucca extract lead to the formation
of nanostructured adsorption layers which are responsible for the very high
elasticity of the oil-water interface and of the respective bulk emulsions.
Remarkably, this extra high emulsion elasticity inhibits the emulsion syneresis
even at 65 vol % of the oil drops. These emulsions remain homogeneous and
stable even after 30 days of shelf-storage. These results demonstrate that the
combination of saponin and phytosterols is a powerful new approach to structure
oil-in-water emulsions with potential applications for formulating healthier
functional food.
