Preparation and characterization of nanoemulsions of curcumin and echium oil

The search for the plant origin bioactive compounds is increasing over animal origin compounds. Echium oil (EO) contains high amounts of plant based omega-3 fatty acids. Moreover, curcumin addition may increase the release of these omega-3 fatty acids during digestion. The study's objective is to determine the bioaccessibility of curcumin in simulated intestinal digestion conditions and the release behavior of fatty acids of echium oil from nanoemulsions. We prepared curcumin and EO nanoemulsions with a microfluidizer using two different concentrations of surfactant, Tween 80 (5% and 10%). Emulsion stability tests, antioxidant analysis, in vitro oil release and fatty acid composition assays were conducted. Results showed that curcumin-containing nanoemulsions provide higher radical scavenging activity than the EO nanoemulsions. In addition, in vitro bioaccessibility of curcumin after in vitro simulated intestinal digestion was calculated as 35.5%. Gas chromatography results of the digested nanoemulsions revealed that curcumin addition decreases oleic acid release while increasing stearidonic acid (SDA) release.