Designing stable walnut oil Pickering emulsions: Interfacial behavior and zero-order release of stigmasterol and β...

To develop stable walnut oil emulsions, this study explored the interaction of phytosterols with walnut protein (WP), high methoxyl pectin (HMP), and gallic acid (GA) complexes, as well as their release mechanisms. Walnut oil Pickering emulsions were stabilized with WP-HMP-GA complexes at varying ratios, enriched with stigmasterol (STI) and β-sitosterol (β SIT). At a WP:HMP-GA ratio of 1:1 30:1, the complex particle size was 55.15 nm, with a contact angle of 68.1° ± 1.3°, improving stability by approximately 22 %. Scanning electron microscopy and Fourier transform infrared spectroscopy confirmed hydrogen bonding and hydrophobic interactions. The emulsions displayed a particle size of 79.43 nm, Zeta potential of -64.56 mV, strong gel network, and significant oxidative stability. Fluorescence spectroscopy and molecular docking revealed β SIT's initial binding, enabling the controlled β SIT, STI with zero-order release. These findings clarify the molecular interactions and release behavior of STI and β SIT from WP-HMP-GA complexes.