Bicelles as a carrier for bioactive compounds in beverages: application to nerolidol, an active sesquiterpene alcohol

Nerolidol is a natural sesquiterpene alcohol with promising but limited application in food and pharmaceutical fields due to several factors including low photostability and low aqueous solubility. Recently, several carriers loading nerolidol were prepared and tested in fresh orange juice. Lipid vesicles loading nerolidol did not exhibit satisfactory organoleptic properties in this beverage. Hence, DMPC/DHPC bicelles were prepared as a new phospholipid-based carrier for nerolidol at different molar ratios. The bicelle suspensions were characterized in terms of homogeneity, particles size, and morphology. The optimal formulation (phospholipid:nerolidol molar ratio 100:1) was selected based on transparent appearance, homogeneity, and particle size (~ 45 nm). Besides, it showed a high encapsulation efficiency of nerolidol and a high incorporation rate of phospholipids. Transmission electron microscopy analysis demonstrated the formation of bicelles. The bicelles membrane fluidity was assessed by 1,6-diphenyl-1,3,5-hexatriene fluorescence anisotropy and differential scanning calorimetry analysis. The membrane fluidity of bicelles appeared to increase in the presence of nerolidol in a concentration dependent manner. To our knowledge this is the first study dealing with the encapsulation of an essential oil component in bicelles.