Comparison of the stability of the nanoliposome form of the citron (Citrus medica L.) peel essential oils obtained from different extraction methods during the storage period at 4ºC and -18ºC

One of the critical methods to maintain the stability and functional properties of plant essential oils as a useful source of bioactive compounds against environmental damage is their encapsulation in nanocarrier systems such as nanoliposomes. In this study, nanoliposome containing the citron peel essential oils were prepared without the use of toxic organic solvent and by employing health-giving compounds such as sesame oil in addition to lecithin for the first time in the formulation. The stability of the samples during 30 days of storage at temperatures of 4ºC and -18ºC was determined by investigating the retention amount of phenolic compounds, pH changes, antioxidant and antimicrobial performance. The nanoliposomal samples of essential oils of hydrodistillation and supercritical CO2 of citron peel prepared with different concentrations of lecithin oil had different quantities of pH and phenol retention percentage, and their amount reduced with increasing storage time at both test temperatures. DPPH inhibitory ability and antimicrobial activity of both citron peel essential oils were improved after encapsulation in nanoliposome. But their amount in both storage temperatures decreased with the advancing of time. The nanoliposome of the supercritical fluid essential oil of citron peel respectively with the formulation containing the highest and lowest amount of lecithin oil at the storage temperature of 4ºC showed the best result in this study. Therefore, the citron peel essential oil with encapsulation in the nanoliposome system prepared from lecithin-sesame oil, due to improvement of antioxidant and antimicrobial activity and its higher stability against storage temperature, can be used as an effective natural functional additive in the food industry.