2-Methyloxolane (2-MeOx) as Sustainable Lipophilic Solvent to Substitute Hexane for Green Extraction of Natural Products. Properties, Applications, and Perspectives

Abstract

This review presents a complete picture of current knowledge on 2-methyloxolane (2-MeOx), a bio-based solvent for the extraction of natural products and food ingredients. It provides the necessary background about the properties of 2-MeOx, not only its solvent power and extraction efficiency, but its detailed toxicological profile and environmental impacts are discussed. We compared 2-MeOx with hexane which is the most used petroleum-based solvent for extraction of lipophilic natural products. The final part focuses on successful industrial transfer, including technologic, economic, and safety impacts. The replacement of petroleum-based solvents is a hot research topic, which affects several fields of modern plant-based chemistry. All the reported applications have shown that 2-MeOx is an environmentally and economically viable alternative to conventional petroleum-based solvents for extraction of lipophilic foodstuff and natural products.

Reinventing the oilseeds processing to extract oil while preserving the protein

“…In a study made at industrial scale, with a desolventizer functioning at atmospheric pressure, prepress-canola cake with 20-25% of oil was brought to a residual oil content of 0.3% and 10 mg/kg of solvents residues. The solubility of proteins resulting from that processing was not specified (Rapinel et al, 2020). According to the website dedicated to this solvent, it is expected to be approved for food applications in the US and Europe in early 2021 (Pennakem, 2020).…”

“…Its toxicity and its environmental impacts should be considered as lower than that of hexane. Unfortunately, this solvent comes with some drawbacks, it is more expensive than conventional hexane, it requires slightly more energy for its recycling and some revamping are required in existing oil-mill to use it (Rapinel et al, 2020).…”

Green Solvent to Substitute Hexane for Bioactive Lipids Extraction from Black Cumin and Basil Seeds

“…Indeed, 2 -methyltetrahydrofuran (MeTHF) is one of the green solvents with a high potential to replace n-hexane. This bio-based solvent is cyclic ether, generated from carbohydrates derived from lignocellulosic biomass, which represents the most abundant biomass resources on earth [ 12 ]. During the process, MeTHF could be recovered and reused allowing cost optimization on solvent losses, as well as on waste disposal.…”

“…Thus, this solvent could be an interesting option in the industry for the companies who want to get rid of petrochemicals residues in their product or claim a clean label production with low cost. Even if the solvent is not recycled, its disposal would be cheaper than the disposable of hazardous petro-based solvents, such as hexane [ 12 ].…”

Alternative and sustainable solvents for green analytical chemistry

“…2-MeOx is produced at industrial scale from agricultural wastes as corn stover or sugarcane bagasse. Its production involves three steps: (i) a harsh acidic treatment of the material for deconstructing lignocellulose and release pentose and hexose sugar units; (ii) a biorefining process for the conversion of C5 and C6 sugar units into furfural and levulinic acid respectively; (iii) several hydrogenation reactions from furfural and levulinic acid to finally obtained 2-MeOx[19].Recently, the potential of 2-MeOx to extract aromas from different matrices was investigated.In 2019, Ozturk et al used 2-MeOx among other bio-based solvents to perform the extraction of limonene from orange peel residues and compared the results to those obtained with hexane…”