Solvent from forestry biomass. Pinane a stable terpene derived from pine tree byproducts to substitute n-hexane for the extraction of bioactive compounds

Abstract

The ability to be used as an alternative solvent of a cis-rich pinane (cis/trans: 7/3), which was obtained for the first time at the multigram scale through an environmentally friendly catalytic hydrogenation of α/β-pinenes or turpentine oil under neat conditions over a Pd/C catalyst, was investigated and compared to n-hexane for the extraction of several bioactive compounds. Experimental evaluation as well as a simulation of the cis-rich pinane extraction capacity have been undertaken. The predictive approach was performed using the simulation software COSMO-RS (conductor like screening model for realistic solvents), which uses a statistical thermodynamics approach based on the result of quantum chemical calculation, for the understanding of dissolving mechanism. COSMO-RS simulation showed that the bio-based solvent is a good solvent to solubilize carotenoids, oil from rapeseed and aromas from caraway seeds. The experimental results indicated that the highest carotenoid yield was obtained with the cis-rich pinane with 95.4% of the maximum carotenoid content in carrots while n-hexane was only able to extract 78.1% of them. With respect to the extraction of oil from rapeseeds, both solvents showed similar extraction yields and no differences were observed in the fatty acid profiles. In relation to the aromas, the characterization of the essential oil extracted by the two solvents showed a similar composition, where carvone (64%) was the main component followed by limonene (34%). No selectivity of the solvents was observed for any of the two major compounds. The results indicate that the bio-based solvent could be a promising solvent for n-hexane substitution.