LAUSR

BACKGROUND Nanoemulsions formulated with citric essential oils are currently of interest because of their physical-chemical properties and multiple applications in areas such as the food industry or agrochemicals. These are thermodynamically unstable and have almost Newtonian flow behaviour, but a suitable formulation allows obtaining systems with good physical stability and rheological properties. The addition of pectin makes this possible. In this work, food nanoemulsions formulated with pectin, orange essential oil (5 wt%) and Tween 80 were obtained by microfluidization. First, the effect of Tween 80 concentration from 1 to 5 wt % on emulsions without pectin was evaluated. Then, the most stable nanoemulsion obtained was used to add the pectin. For it, two variables were studied: the pectin solution concentration (from 2 to 6 wt%) and the pectin / emulsion ratio (1/1 or 2/1) at a fixed pectin concentration. RESULTS Rheological, laser diffraction, and multiple light scattering techniques were employed to determine the content of Tween 80 that results in the most stable nanoemulsion without pectin which was 3 wt %. In addition, these techniques were used to determine the structure and physical stability of the nanoemulsions containing orange essential oil and pectin. The results obtained determined that the emulsions containing 2 wt % pectin were destabilized before 24 h. Furthermore, the emulsion with 6 wt% pectin and pectin/ emulsion ratio of 2/1 showed the highest viscosity and the lowest mean diameters, therefore, the greatest stability. CONCLUSION This work extends the knowledge of formulation of nanoemulsions and using essential oils. This article is protected by copyright. All rights reserved.