Speaker
Description
Structuring liquid vegetable oils into semi-solid networks provides a viable route to replace saturated and trans fats, which oleogel dispersed in aqueous food matrices require interfacial protection to remain physically stable. Herewith, an olive oil nano-oleogel was structured with glyceryl monostearate (GMS) and encapsulated within a lecithin–pectin bilayer assembled by electrostatic bilayer deposition. GMS with 3, 5, and 7% (w/w), and 5% was selected as the optimal structurant on the basis of dynamic light scattering with size of 789 nm. Bilayer nano-oleogels were subsequently constructed at three lecithin:oleogel ratios (1:1, 1:2, and 1:4, v/v; oleogel fixed at 20 mL) across pH 3–5 and characterized by particle size analysis, zeta potential, ATR-FTIR, static viscosity, and oil binding capacity (OBC). pH 5 produced the most stable colloidal dispersion through near-complete ionization of pectin carboxyl groups. At pH 5, every formulation surpassed zeta potential in < - 30 mV stability threshold (−45.13, −52.83, and −68.17 mV for 1:1, 1:2, and 1:4), the surface charge becoming progressively more negative as the anionic low-methoxyl pectin contribution outweighed zwitterionic phosphatidylcholine at the interface. A pronounced functional trade-off emerged: OBC declined as lecithin volume decreased (94.99, 72.41, and 54.43%), whereas static viscosity rose sharply (463.0, 1760.0, and 2620.0 cP). ATR-FTIR showed no major band shifts, indicating stabilization governed by non-covalent physical interactions rather than new covalent linkages. Overall, the 1:1 formulation at pH 5 offered the best balance of oil immobilization, particle homogeneity, and electrostatic stability, positioning bilayer-encapsulated olive oil nano-oleogels as a clean-label platform for structured-lipid and lipophilic-bioactive delivery applications.
