Evaluation of Microcapsules with Lavender Essential Oil

Abstract

Background: Lavender is one of the most valuable medicinal and aromatic plants, due to the content of essential oil [1]. However, its volatility and instability complicate its use in pharmaceuticals and cosmetics. Microencapsulation effectively protects the essential oils from external factors, preserving their beneficial properties for a long time [2]. Aim: To study the technological properties and stability of microcapsules with lavender essential oil prepared by spray- and freeze-drying methods. Research objects: Maltodextrin (MD) with DE (13-17), gum arabic (GA), lavander essential oil (LO) were used. Four emulsion compositions with 30% solids content were prepared, varying GA:MD ratios (25:5, 20:10, 15:15, 10:20) and keeping LO constant at 5 g per 100 ml of emulsion. The powders prepared by spray- and freeze-drying were analyzed for moisture, solubility, yield, Carr index (CI), and Hausner ratio (HR). The LO content in the microcapsules was determined by gas chromatography with flame-ionization detection analysis. Results: All microcapsule samples were characterized by low moisture content (5-6%) and good solubility (91-98%). Moreover, there was a tendency that with increasing MD in the microcapsule composition, the solubility increased, and the moisture content decreased. In addition, all microcapsule samples were characterized by poor flowability, as confirmed by the CI and HR. However, the powders obtained by the freeze-drying were characterized by a significantly higher yield of the finished product. The study of the microcapsules’ stability during 3 months of storage at room temperature showed that the lowest losses of the main components of lavender essential oil, namely linalool and linalyl acetate, were observed when using the ratios of encapsulating agents GA 25:5 MD and GA 20:10 MD. Conclusion: According to the results, freeze-dried microcapsules had nearly twice the yield of spray-dried powders. Stability tests showed that GA:MD ratios of 25:5 and 20:10 provided better encapsulation than other samples.