Conventional and emerging techniques in the extraction and microencapsulation of essential oils

Abstract

Essential oils are volatile and concentrated products from plant secondary metabolism, with increasing interest due to their wide applications in food, pharmaceutical, cosmetic, and agricultural sectors. This review discusses the primary methods for extracting and microencapsulating essential oils, emphasizing approaches with greater environmental and economic viability for industrial application. Their chemical composition and properties are strongly influenced by the extraction method. Conventional methods, like hydrodistillation, have limitations, leading to the rise of innovative techniques such as supercritical fluid extraction, microwave-assisted extraction, and ultrasound-assisted extraction. These green technologies offer advantages like reduced extraction time, lower solvent consumption, and improved selectivity and energy efficiency. After extraction, microencapsulation is crucial for protecting essential oils from degradation, increasing stability, and controlling the release of bioactive compounds. This process involves encasing essential oils in an encapsulating matrix and forming microcapsules using physical, chemical, or mechanical methods. The choice of encapsulating material is vital for product stability. The extraction and microencapsulation of essential oils are interdependent processes where the extraction method impacts oil quality, and the microencapsulation's particle size and properties directly influence stability, release, and protection against external factors. This study showed that optimizing these parameters is crucial for developing efficient microencapsulated products with promising applications.