Interfacial adsorption and stability performance of octenyl succinic anhydride-modified β-cyclodextrin/xanthan gum nanoparticles stabilized cinnamon essential oil Pickering emulsions

In this study, novel composite nanoparticles (OX-DH) were prepared via dry-heat conjugation between octenyl succinic anhydride-modified β-cyclodextrin (OSA-β-CD) and xanthan gum (XG), and were applied as particulate stabilizers for cinnamon essential oil Pickering emulsions. The effects of dry-heat modification on the molecular interactions, microstructural features, amphiphilic wettability, and component binding behavior of OX-DH were systematically explored. Meanwhile, the droplet morphology, particle distribution, storage stability, thermal stability, and centrifugal stability of the resulting Pickering emulsion were evaluated. The results indicate that dry-heat treatment effectively strengthens intermolecular non-covalent interactions, optimizes the surface amphiphilicity, and improves their interfacial adsorption performance. The oil-water-solid three-phase contact angle increased from 68.75 ± 1.80° (OSA-β-CD) to 82.53 ± 1.85° for modified OX-DH, accompanied by an emulsifying activity index of 2.877 m2/g. The optimized OX-DH enable rapid adsorption and dense arrangement at the oil-water interface, forming a compact and rigid interfacial film that inhibits the coalescence and flocculation of emulsion droplets. This unique interfacial structure endows the emulsion with uniform droplet size, favorable environmental adaptability, and superior colloidal stability during 35 days of storage at 25 °C. Furthermore, the emulsion retains a low peroxide value of 6.06 mmol/kg after 21-day storage, demonstrating outstanding oxidative stability. This work provides a reliable strategy for fabricating high-stability functional essential oil Pickering emulsions.