Enhancing fractionation of terpenoids and terpenes in citrus essential oils by a biphasic extraction system

Efficient deterpenation of essential oils is crucial for obtaining high value-added products. In this work, a biphasic extraction system integrated with associative extraction was utilized to enhance fractionation of terpenoids and terpenes, where organic salt and organic solvent were employed as extractants in each phase. Ten different organic solvents were evaluated in terms of their phase behavior, extraction performance, and EHS-related properties. The positive or negative effect of organic solvents on biphasic extraction performance was elucidated through molecular dynamics simulations and FT-IR spectra analysis. The results indicate that an organic solvent lacking hydrogen bonding ability can reduce its interaction with organic salt or terpenoids, thereby exerting a positive contribution to biphasic extraction. For crude orange sweet essential oil, the biphasic system containing tetrabutylammonium chloride and n-hexane achieves a 6.2-fold concentration of terpenoids, demonstrating its effectiveness in enhancing extractive deterpenation of essential oil.