Encapsulation of rutin and naringenin in multilamellar vesicles for optimum antioxidant activity

Rutin and naringenin, two phenolic compounds with antioxidant properties were encapsulated in lipid-based onion-type multilamellar vesicles (MLVs). After vesicles formation, the free, adsorbed/encapsulated analytes were well separated with size exclusion chromatography (SEC), and rutin and naringenin were quantified with UV-HPLC at 258 nm and 290 nm. A mathematical model was developed to separately calculate the encapsulation and the adsorption yields of both phenols. Naringenin was shown to be poorly encapsulated (<10%) but highly adsorbed on MLVs surface (>60%) whatever MLVs composition. Conversely, rutin showed high encapsulation efficiency (>60%). Entrapment of rutin was proved to be efficient since no leak was observed within 30 days in concentrated MLVs phase, while 16.0 +/- 0.3% of rutin was still encapsulated after 30 days when MLVs were diluted in water. Free rutin broke up into quercetin while the encapsulated one remained stable. DPPH assay confirmed that only free and adsorbed rutin participated in antioxidant activity. (C) 2014 Elsevier Ltd. All rights reserved.