Antioxidant Activity of Essential Oils: A Mechanistic Approach

Essential oils (EOs) have long been extracted using a variety of techniques from different aromatic and therapeutic plants. Because of their antioxidant quality and attractive fragrances, they have found broad utilisation in various fields as antioxidant, antibacterial, and antifungal agent in pharmaceutical, cosmetic, and food sectors. Antioxidants are a group of compounds that can prevent oxidation by acting as reducing agents, pro-oxidant inactivators, free radical scavengers, and radical species quenchers. Reactive oxygen species (ROS) interact with any material that may be oxidised and modify the structural makeup of the material as a result, causing oxidative damage. There are plenty of approaches available for the estimation of antioxidant activities of Eos; ABTS (2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) and DPPH (1,1-diphenyl-2-picrylhydrazine) assays are frequently used methods. Since EOs contain a variety of active components, their antioxidant mode of action cannot be achieved by a single method of action. The EOs and its nanoencapsulated products are more effective as free radical scavengers in nature due to slow release, longer shelf life, and easily available in the medium without direct interference with food matrix. The application of EOs as antioxidants in real food systems have been associated with some hurdles, which could be overcome using the encapsulation technology and advanced food packaging systems. In this chapter, the antioxidant properties of EOs, estimation of antioxidant activities, mechanisms involved in antioxidant activity, encapsulation process with enhanced activity and applicability, its application in real food systems, and future possibilities have been discussed.