Innovative and ecofriendly methods and pretreatments for essential oil extraction: An update

CAVALLARO, VALERIA; MURRAY, ANA PAULA; FERREIRA, MARÍA LUJÁN

Studies in Natural Products Chemistry

Elsevier

Año: 2023; p. 481 - 518

Historically, a variety of essential oils (EOs) have been used for their aroma and flavor aswell as for the important biological activities they display such as antibacterial,antioxidant, antifungal, antiparasitic, antiviral, enzyme inhibitor and insecticide.Nowadays, EOs have several important applications in the pharmaceutical, food,cosmetic and agricultural industries. Various investigations have revealed that thecomposition and quality of EOs can be altered due to the extraction methods andsolvent used. The most common extraction methods include hydrodistillation (HD),steam distillation (SD), cold pressing and solvent extraction. Although these techniqueshave been known and studied for many years, their application is time-consuming andshows a large number of disadvantages, such as the loss of highly volatile compounds,low extraction efficiency and possible toxicity due to the presence of residual solvents.As a consequence, and in search of environmentally friendly methods, innovative andalternative techniques are currently available to improve the recovery of these naturalproducts. Most of these methods are based on the degradation or disruption of theplant cell wall to better release the inner components. Among them, we can highlightthe use of cellulases, hemicellulases, pectinases, oxidases and combination of them asenzymatic pretreatment, the use of supercritical CO2 as an extraction medium,ultrasound, microwave and ohmic heating-assisted extraction. Recently, the field of(bio)mimetics of enzymes has growth, mainly in case of oxidoreductases, and theapplication in oxidative degradation of the plant cell walls is in the beginning. In thischapter, emergent and ecofriendly pretreatments (and the combination with extractionprocesses that could be easily applied in large-scale industrial production) have beencritically reviewed. Also, insights into the mechanism of action of each process havebeen discussed. Finally, conclusions and future perspectives as well asrecommendations have been highlighted in this chapter.