Innovations and modifications of current extraction methods and techniques of citrus essential oils: a review

The genus Citrus of the Rutaceae family remains one of the beneficial fruit crops that produce high quantities of essential oils that have pharmaceutical, biological, and food preservative applications. Despite the numerous benefits of citrus essential oils (CEOs), there is a major challenge in choosing the most efficient extraction method(s) for large-scale production of quality CEOs to meet industrial, research, and domestic demands. This review provides a general overview of the listed citrus species, the chemical composition of their essential oils, medicinal uses, and the major methods of extraction of citrus essential oils from 10 selected citrus species. A meticulous, in-depth review of the various methods of CEOs extraction has been provided, along with their advantages, limitations, and novel modifications. This comprehensive literature review expounded on the current extraction methods for citrus essential oils and the various modifications developed to reduce the extraction time, excessive energy consumption, CO2 production, and quality, as well as to improve the extraction yield.