Nanostructured lipid carrier (NLC) as a strategy for encapsulation of quercetin and linseed oil: Preparation and in vitro characterization studies

Due to their poor solubility in hydrophilic matrices and chemical instability, the applications of quercetin and linseed oil in functional foods are limited. In this work we have encapsulated quercetin and linseed oil into NLC by high pressure homogenization technique. Quercetin and linseed oil co-loaded nanoparticles were less than 100 nm in diameter and spherical in shape. Nano-encapsulated quercetin was found to be presented in NLC with less ordered lipid cores as an encapsulated amorphous form. And the solubility of quercetin in hydrophilic matrices consisted of linseed oil and surfactants was improved by at least 1300 folds. The addition of linseed oil improved the in vitro antioxidant activities of quercetin loaded NLCs. Besides, the in vitro release of quercetin from NLC exhibited a sustained pattern. Lower lipid oxidation was found in quercetin and linseed oil co-loaded NLC compared with conventional linseed oil emulsion. Finally, storage study indicated that the fabricated NLCs were stable for more than 3 months at 25 °C. In conclusion, NLC could be a promising vehicle for delivery of hydrophobic bioactive compounds and ω-3 unsaturated fatty acids in food industry.