Oilseeds extraction using 2-methyloxolane as an alternative bio-based solvent to hexane

Abstract

Despite its known toxicity, hexane remains the state-of-the-art reference for solvent extraction of oilseeds. Alternatives have been studied and developed in the past decades, but none was competitive enough so far. Since 2012, a new bio-based solvent - 2-methyoxolane (2-MeOx) - appeared in the industry with several scientific publications showing its potential for the extraction of various oilseeds. However, only few research was published on major oilseeds such as soy, sunflower, or rapeseed. Following an exhaustive work already shared on soybean, we are now presenting our latest scientific research on rapeseed.First, the extraction products from rapeseed were analyzed and compared to those obtained with hexane using identical protocols. Then, several process parameters and conditions (yields, kinetic study, multi-stage extractions, etc.) were evaluated to better understand the impacts of the solvent switch.Experimentally, 2-MeOx gave higher crude extraction yields compared to hexane, with 28.3% vs 22.6%. As the crude oils main composition were similar, yield differences were attributed to the co-extraction of more polar additional compounds such as phospholipids and phenolic compounds. Interestingly, such phenolic antioxidants (mostly sinapic acid derivatives), which are usually not extracted using hexane, were found at 1-2% levels in the crude oils extracted using 2-MeOx. Regarding the defatted meals, no significant difference was observed in terms of crude protein and amino-acid contents. Advantageously, some of the antinutritional factors were significantly reduced when using 2-MeOx as lipophilic solvent. Up to now, the kinetic study and multi-stage cross-current extractions have shown that hexane and 2-MeOx have similar behavior. Overall, the results of this study reveal that 2-MeOx has a good potential to replace the standard solvent used in the oilseeds industry, as this alternative bio-based solvent provides oils and meals with similar quality when compared to hexane while exhibiting a similar behavior during extraction.