Green solvents and approaches recently applied for extraction of natural bioactive compounds

Abstract

Consumption of large volumes of toxic organic solvents in chemical processes can trigger both health and environmental problems. Therefore, “green chemistry” is getting increasingly important. Significant efforts have already been devoted to reduction of the utilization of hazardous organic solvents and continuation of these attempts remains a viable task. In this context, a diverse range of more sustainable solvents including deep eutectic solvents, bio-based solvents, supercritical carbon dioxide, and gas-expanded liquids has been introduced and their applications explored in both research and industry. Our review focuses on the properties, environmental effects, toxicity, and applications of these solvents in the extraction of natural bioactive compounds described in papers published since 2018. Moreover, some common sustainable extraction techniques including supercritical fluid, microwave-assisted, and ultrasound-assisted extractions are covered and compared in terms of the extraction efficiency. In addition, some common chemometric approaches that are widely used for the optimization of the processes related to the extraction of bioactive compounds are also presented.