Uses of ionic liquids to obtain bioactive compounds: insights from the main international regulations for technological applications

Abstract

Ionic liquids (IL) are innovative alternative solvents to recover bioactive compounds from plant-based sources to replace toxic volatile organic solvents (VOS). ILs are tailored-made solvents with chemical and thermal stabilities, nonvolatile and noninflammable. Although ILs are versatile, cost-effective, and sustainable solutions, the European Commission (EC) has no current regulation to approve extracts obtained with ILs to be applied in foods. Herein, this paper aims to assess the overview of ILs, regulamentation, applications, and its toxic effects, to be used as solvents for extract different bioactive compounds. Studies have suggested novel applications for ILs, such as 1-butyl-3-methylimidazolium bromide, 1-butyl-3-methylimidazolium chloride, 1-butyl-3-methylimidazolium tetrafluoroborate and others, to obtain bioactive compounds, for instance phenolic compounds, lignans, alkaloids, carotenoids, polysaccharides, using modern approaches as ultrasound and microwave-assisted extraction. New IL methods increase the efficiency of recovering target compounds and decrease the extraction time and VOS consumption regarding the traditional techniques. Furthermore, to promote the large-scale use of IL in foods, it is essential to investigate individually the toxicity of each IL used in the extraction processes, aiming to obtain a GRAS stamp, due to the currently lack of regulamentation.

Keywords:

• Innovative solvents
• extraction methods
• ultrasound-assisted extraction
• toxicity of ionic liquids
• volatile organic solvents
• EU regulations

Acknowledgements

The authors are thankful to Flaticon (https://www.flaticon.com) and Canva (https://www.canva.com) for the icons used in the figures.

Disclosure statement

The authors report there are no competing interests to declare.

Additional information

Funding

The authors are grateful to the Foundation for the Support of Research and Innovation in the State of Santa Catarina (FAPESC, Brazil) for the graduate scholarship (Project n. 88887.177804/2018-00) and to the Coordination for the Training and Improvement of Higher Education Personnel (CAPES, Brazil) for the financial support (Academic Excellence Program - PROEX).