Abstract
The potential of using the bio-based solvent 2-methyloxolane, also known as 2-methyltetrahydrofuran or 2-MeTHF, as an alternative to petroleum solvents such as hexane, was investigated for the extraction of volatile compounds from hop cones (Humulus lupulus L.). Lab scale extractions were coupled with in silico prediction of solutes solubility to assess the technical potential of this bio-based solvent. The predictive approach was performed using the simulation software COSMO-RS (conductor like screening model for real solvants) and showed that the 2-methyloxolane is as good as or better than hexane to solubilize the majority of aromas from hop cones. The experimental results indicated that the highest aroma yield was obtained with 2-methyloxolane with 20.2% while n-hexane was only able to extract 17.9%. The characterization of aromas extracted by the two solvents showed a similar composition, where lupulone was the main component followed by humulone. No selectivity of the solvents was observed for any of the major analytes. Finally, a sensory analysis was performed on the extracts, showing that both concretes using 2-methyloxolane and hexane have similar olfactory profiles. The results indicate that 2-methyloxolane could be a promising bio-based extraction solvent for hexane substitution.
Highlights
In solid–liquid extraction, it is commonly admitted that extraction efficiency strongly depends on the solvent, as described by Choi and Verpoorte [1]: “What you see is what you extract”
This study aims to evaluate under the green chemistry concept the performance of 2-methyloxolane as a hexane substitution solvent for extraction of food aromas from hop cones
The results, expressed as log10, the logarithm of the molar fraction of solute in the solvent, show a much higher theoretical solubility of the analytes in 2-methyloxolane, in particular humulone and lupulone which are more polar than humulene. Both n-hexane and 2-methyloxolane have a large surface with a neutral charge density that allows favorable interactions with other lipophilic surfaces, in particular humulene, but the specificity of 2-methyloxolane comes from the presence of the oxygen atom in the oxolane group which allows interactions with dipoles found in humulone
Summary
In solid–liquid extraction, it is commonly admitted that extraction efficiency strongly depends on the solvent, as described by Choi and Verpoorte [1]: “What you see is what you extract”. Hexane is considered to be the best solvent for the extraction of lipophilic molecules such as lipids, aromas, and colors such as carotenoids [2] and the reason why it is widely used in the extraction industry. Besides their obvious advantages, these solvents present negative aspects. In most cases, they are obtained from non-renewable resources often petroleum-sourced, VOC (volatile organic compound) emitters, and harmful to human health and the environment. N-hexane, the major isomer of hexane, is known to be neurotoxic and hazardous for the environment [3,4]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
