Targeted delivery and controlled released of essential oils using nanoencapsulation: A review

Essential oils (EOs) contain a complex mixture of volatile and non-volatile molecules with diverse biological activities, including flavoring, antioxidant, antimicrobial, and nutraceutical properties. As a result, EOs have numerous potential applications in the agriculture, food, and pharmaceutical industries. However, their hydrophobicity, chemical instability, and volatility pose a challenge for many of their applications. These challenges can often be overcome by encapsulation EOs in colloidal delivery systems. Over the last decade or so, nanoencapsulation and microencapsulation technologies have been widely explored for their potential to improve the handling, dispersibility, and stability of hydrophobic substances, as well as to control their release profiles (e.g., targeted, triggered, sustained, or burst release). These technologies include emulsification, coacervation, precipitation, spray-drying, spray-cooling, freeze-drying, fluidized bed coating, and extrusion. This article reviews some of the most important developments in EOs encapsulation, the physicochemical mechanisms underlying the behavior of encapsulated EOs, current challenges, and potential applications in the food and biomedical sciences. This review has found that nanoencapsulation has countless of potential advantages for the utilization of EOs in the food industry and can improve their water-dispersibility, food matrix compatibility, chemical stability, volatility, and bioactivity.