Preparation of curcumin-loaded emulsion using high pressure homogenization: Impact of oil phase and concentration on physicochemical stability

•The maximum solubility of curcumin was acquired in MCT with ultrasonic treatment.•Curcumin nanoemulsion prepared by MCT and Tween-80 exhibited the best stability.•Higher oil concentration led to higher curcumin content but lower stability.

Curcumin is a natural food coloring agent with many pharmacological effects such as anti-oxidation and anti-cancer. In this study, curcumin was dissolved in different oil phases (medium chain triglyceride, canola oil and linseed oil) by different treatments (heat, ultrasonic and microwave). Curcumin nanoemulsions stabilized by different emulsifiers (Tween-80, lecithin, whey protein isolation and acacia) with different concentrations were prepared using high pressure homogenization to evaluate physicochemical properties including curcumin content, particle size, potential, physical stability and storage stability (variation of curcumin content and particle size under different temperatures in 60 days). The increase in oil phase concentration caused increase in curcumin content, particle size and viscosity of the emulsions but decrease in stability. Meanwhile, temperature significantly affected the stability of nanoemulsion stabilized by lecithin instead of Tween-80. Curcumin nanoemulsion could achieve the maximum curcumin content when choosing medium chain triglyceride as its oil phase. These results may broaden the application of curcumin in food industry for improving its solubility and bioavailability.