Encapsulation of Rosa damascena Mill. essential oil in nanoliposomes: Physicochemical and antioxidant activity features

Rosa damascena Mill. essential oil (EO) was encapsulated in nanoliposomes to overcome its low stability and limited solubility. The fabrication of EO-loaded nanoliposomes (EO-LNLs) was optimized based on the response surface methodology (RSM) with central composite face-centred (CCF) design. Different concentrations of EO (500, 1000, and 1500 ppm) and lecithin (0.5, 1.25, and 2% w/v) were applied for preparing nanoliposomes. The obtained nanoliposomes had a particle size of 82-124 nm, a zeta potential of -55 to -30 mV and a polydispersity index (PDI) of 0.270- 0.342. The nanoliposomes prepared with 1.56% lecithin and 500 ppm of EO had the best properties with the encapsulation efficiency of 84%. The results obtained from different instrumental methods (DSC, FT-IR, and TEM) verified the encapsulation of EO in nanoliposomes. According to the antioxidant activity evaluations based on DPPH⁰, ABTS⁰+, and FRAP assays, free EO had higher radical scavenging activity and lower EC50 than encapsulated EO. The highest in vitro release of EO from nanoliposomes occurred at pH=3. During the storage of nanoliposomes for seven weeks at 4oC, their particle size was increased by 7.0%. Accordingly, one can deduce that encapsulation of Rosa damascena Mill. EO in nanoliposomes can protect it against undesirable conditions and keep its properties. Therefore, it can be suggested to be used, as a natural preservative, in different matrixes such as food, medicine, and cosmetic industries.