Amorphous nano-curcumin stabilized oil in water emulsion: Physico chemical characterization

•Curcumin is nanonized to reduce size and change polymorphism.•Nanonized curcumin is amorphous in nature.•Protein avoided recrystallization of nanonized curcumin.•Nanonized curcumin reduced interfacial tension between oil and water.•Nanonized curcumin stabilized emulsions are stable for 30 days at 4 °C.

Particle characteristics e.g. size and polymorphism are known to significantly affect the Pickering ability of the solid particles by influencing their interaction at the oil and water (O/W) interface. In this study, nano-sized amorphous curcumin particles were fabricated using nanonization technology to use them as Pickering particles.After nanonization, native crystalline curcumin particles were converted into amorphous, nanosized particles of ∼220 nm. Amorphous nature of the particle was evident from the decreased melting point from 177 ± 1 °C (native curcumin) to 146 ± 3 °C (nanonized curcumin) and enthalpy from 27 ± 2 J/g to 3.5 ± 1 J/g.Interfacial tension (IFT) studies have shown a decrease in IFT at the O/W interface from ∼27 mN/m to ∼15 mN/m in the presence of amorphous curcumin particles in water phase compared to crystalline curcumin particles. Curcumin stabilized O/W emulsion has an initial droplet size of ∼1.2 μm and they were stable for 30 days at 4 °C.