Stabilization of high internal-phase Pickering emulsion using nobiletin crystals: assembly of supramolecular metal-polyphenolic coordination complexes for surface coating.

Background: High internal-phase Pickering emulsions have attracted interest due to their unique properties and they have the potential for broad application in the food field, for example as fat replacers, for packaging, for delivery of nutrients or probiotics, and in the 3D printing of food. However, efficient and edible high internal-phase Pickering stabilizers are still a persistent challenge for food scientists.

Results: Nobiletin (NOB) was selected as a model substance. The particles' physicochemical properties (droplet size, rheological behavior, and transmission profile) showed that supramolecular metal-polyphenolic coordination networks could suppress the ripening and growth of crystals on the oil-water interface. When the ratio of tannic acid (TA) to Fe was 3:1, the growth of NOB crystals could be inhibited effectively. Due to the reduction of energy steric hindrance in the adsorption process, the resulting NOB-TA -Fe (NT Fe ) nanoparticles had the greatest potential to extend emulsion storage time.

Conclusion: The NOB-TA -Fe (NT Fe ) nanoparticles were able to stabilize a high internal-phase emulsion, of which the oil phase was 80%, for at least 30 days, eventually leading to high system viscosity. The findings in this work provide a novel selection of healthy emulsifiers and an effective emulsion delivery system for hydrophobic and crystalline nutrients. © 2023 Society of Chemical Industry.