Stabilization of sesame oil-in-water emulsions by synergistic complexation of tea saponin and gum arabic: Stability and rheological characterization

This work aimed at developing a stable oil-in-water microemulsion by electrostatically assembling tea saponin (TS) with varying concentrations of gum arabic (AG). Particular emphasis has been given to rheology, droplet size distribution, ζ-potential measurements, and microscopy to investigate their underlying relationship with emulsion properties. A small concentration (0.1–0.4 %) of AG efficiently interwoven with TS to produce synergistic effects, such as reduced droplet size, improved viscosity, and homogenous appearance, endowed final emulsions with enhanced stability. Across fluctuating pH, temperature, freeze-thaw cycles, and ionic strengths, AG-added emulsions sustained significantly lower droplet growth and maintained higher ζ-potential values after fourteen days. In addition, Fourier transform infrared (FTIR) analysis identified strong intermolecular hydrogen bonding between AG and the sugar chains of TS, which reinforced the fibrous interfacial network of TS, resulting in excellent rheological properties. These findings suggest that TS/AG co-stabilized emulsions foster promising potential as innovative fat replacers in food formulations.