Origin of the extremely high elasticity of bulk emulsions, stabilized by Yucca Schidigera saponins
Tsibranska, Sonya ; Tcholakova, Slavka ; Golemanov, Konstantin ; Denkov, Nikolai ; Arnaudov, Luben ; Pelan, Eddie ; Stoyanov, Simeon D. - \ 2020
Food Chemistry 316 (2020). - ISSN 0308-8146
Drop aggregation - Drop-drop adhesion - Emulsion - Emulsion elasticity - Interfacial elasticity - Non-purified oil - Phytosterols - Saponin
We found experimentally that the elasticity of sunflower oil-in-water emulsions (SFO-in-W) stabilized by Yucca Schidigera Roezl saponin extract, is by >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.