Effect of maltodextrin and whey protein concentrate on thyme essential oil nanoemulsion

The purpose of this study was to investigate the effect of maltodextrin (MD)-whey protein concentrate (WPC) mixture on physical properties of thyme essential oil nanoemulsion. For this purpose, ultrasonically-prepared emulsions (containing 5% (w/w) thyme essential oil) were prepared using mixture of MD and WPC at different concentrations (10, 20 and 30% w/w) and different ratios (25:75, 50:50 and 75:25). Emulsion properties such as droplet size, viscosity, flow properties and physical stability were studied. Results indicated that MD-WPC ratio and concentration of suspension had significant effect on emulsion properties. Mean diameter of droplets were between 128.5621-232.6310 nm, while droplet size of emulsions with maltodextrin was smaller than those for proteins. Same results observed for viscosity. On contrary, emulsion stability decreased with increasing WPC concentration. For all emulsions, increasing the concentration of MD-WPC from 10 to 30% w/w increased the particle size, viscosity and decreased their stability.