Investigation of self-assembly of daucosterol from eleocharis dulcis peel with γ-oryzanol for stabilized water-in-oil emulsion gels

Abstract

This study investigated the novel application of daucosterol, a natural saponin from eleocharis dulcis peel, in stabilizing emulsion gels with γ-oryzanol. While daucosterol has known health benefits, its ability to stabilize emulsion gels had not yet been explored. This research examined the emulsification properties, microstructure, rheological behavior, stability, and intermolecular interactions of the resulting emulsion gels. Results showed that daucosterol effectively stabilized the emulsion gels, forming structured networks at higher concentrations. FT-IR analysis revealed significant intermolecular hydrogen bonding between daucosterol and γ-oryzanol, and XRD profiles indicated a transition from crystalline to amorphous structures. SEM images displayed denser network formations with increased daucosterol levels. Contact angle measurements demonstrated enhanced hydrophobicity with rising daucosterol concentration, which favored stable water-in-oil emulsions. Rheological assessments confirmed strong thermal stability, robust mechanical properties, and partial thixotropic recovery at higher daucosterol levels. Additionally, daucosterol-stabilized emulsions showed remarkable stability through storage, freeze-thaw cycles, and heat treatments. This stability was attributed to dense, network-like structures that effectively inhibited phase separation and droplet coalescence. Molecular interaction simulations further supported the formation of stable complexes between daucosterol and γ-oryzanol, sustained by hydrogen bonds and van der Waals forces. This study highlights daucosterol's potential as an innovative stabilizer for oil-water emulsion gels.