Green Extraction Techniques to Obtain Bioactive Concentrates Rich in Terpenoids

Terpenoids, also called isoprenoids or terpenes, are a large class of natural products which display a wide range of biological activities. They are major constituents of essential oils produced by aromatic plants and tree resins. Due to their notable biological activities, these compounds have enormous economic importance, being widely used as bioactive ingredients in the food, cosmetic, and pharmaceutical industries. The growing demand from consumers and regulatory agencies to develop green sustainable industrial processes has resulted in the emergence of new technologies for obtaining bioactive compounds from natural sources. Thus, many works have been reported in the literature regarding the development and application of new methods for obtaining terpenoids from natural sources that meet the demands of green processes, with reduced consumption of solvent and energy, less waste generation, and use of non-toxic solvents. This chapter proposes to present the main methods of green extraction to obtain terpenoids-rich extracts, with an emphasis on low-pressure methods, such as microwave-assisted extraction (MAE) and ultrasound assisted extraction (UAE); and high-pressure methods (here considered as pressures greater than 5 bar), including extraction with supercritical fluids (SFE), subcritical water (SWE) and liquefied petroleum gas extraction (LPG). In addition, the future perspectives and the main challenges regarding the development of alternative methods for the recovery of terpenoids are presented and discussed.