Investigation of Yarrow Essential Oil Composition and Microencapsulation by Complex Coacervation Technology

Abstract

Yarrow (Achillea millefolium L., AM) is a widely used medicinal plant, with its essential oil highly valued in the cosmetic industry. In view of the numerous biological effects, however, microencapsulation, due to its ability to protect sensitive constituents, transform liquids into solid-state material, and provide modification of release kinetics, might open up new possibilities for the biomedical utilization of yarrow essential oil (AMO). In the current work, yarrow plantation was established by its propagation from spontaneous flora. Following the steam distillation of aerial parts, the chemical composition of the essential oil was determined by GC-MS analysis and compared with two commercial samples. This study concludes that Achillea millefolium L. from this region, given the environmental conditions, produces high-azulene-content essential oil. Furthermore, microencapsulation of AMO was successfully performed by complex coacervation into gelatin (GE) and gum arabic (GA) based core–shell microcapsules (MCs). According to the optical microscopic investigation, the particle sizes of the formed polynucleated microcapsules ranged from 14 to 132 µm, with an average of 47 µm. The assessment of morphology by SEM analysis of the freeze-dried form revealed a sponge-like character with embedded circular structures. The microencapsulation was confirmed by FT-IR spectroscopy and differential scanning calorimetry (DSC), while an encapsulation efficiency of 87.6% was determined by UV spectroscopy. GC-MS analysis revealed that microencapsulation preserves the key components of the essential oil. It was concluded that AMO can be effectively processed by complex coacervation followed by freeze-drying into solid-state material for new applications.

Keywords

• microencapsulation
• complex coacervation
• essential oil
• <i>Achillea millefolium</i> L.