Ran Zhu, Beshoy Morkos, Lingling Liu
Essential oils (EOs) are volatile, strongly aromatic bioactive substances extracted from plants, primarily composed of terpenes, terpenoids, phenylpropanoids, and other oxygenated compounds. Owing to their unique chemical structures, EOs exhibit a wide range of biological activities, including antimicrobial, anti-inflammatory, antioxidant, anticancer, neuroprotective, bone-protective, wound-healing, and gut microbiota-modulating effects, highlighting their potential therapeutic value. However, the composition and bioactivity of EOs are influenced by multiple factors and often compromised by improper storage conditions such as temperature and light exposure, leading to the gradual loss of their functional properties. To overcome these limitations, encapsulation technologies have been employed to enhance EO stability, enable sustained and targeted release, and preserve or even improve their bioactive functions. This review summarizes the major constituents of EOs, their physiological activities, therapeutic value, and mechanisms of action. It also discusses their limitations and suitable encapsulation technologies, materials, and carrier systems for stabilization and delivery.