Essential oil (EO) is a mixture of low molecular weight constituents that are responsible for its characteristic aroma. These constituents include terpenoid and non‐terpenoid hydrocarbons and their oxygenated derivatives. This chapter focuses on the heterogeneous composition of the essential oils. It discusses the usage of essential oil constituents as a key marker of the oil quality, freshness and unique characteristics. It describes the biological activity and synergistic effect of the essential oil constituents as antioxidant, antibacterial, antifungal and anticancer agents.
Part of the book: Active Ingredients from Aromatic and Medicinal Plants
Essential oils are formed by a complex matrix of substances that are biosynthesized in the secondary metabolism of plants. Nowadays, different ecofriendly extraction techniques (e.g., ultrasound-, microwave-, enzyme-assisted extraction, and supercritical fluid by CO2, etc.) have been adopted to obtain essential oils. These techniques provide unique quality of essentials oils or extracts from aromatic plants in a short time with high energy savings. Essential oils not only impart aroma, but also possess antimicrobial and antioxidant activities. Health limitations in the use of synthetic additives have drawn researchers’ attention towards essential oils as safe natural preservatives. Therefore, this chapter summarizes novel technologies to recover essential oils or extracts. In addition, it focuses on application of essential oils and their constituents as green preservatives to retard microbial growth and oxidative spoilage.
Part of the book: Essential Oils