Mary Kate M. Lane a b 1, Elise B. Gilcher b c 1, Melissa M. Ahrens-Víquez a, Rachel S. Pontious a, Nora E. Wyrtzen d, Julie B. Zimmerman a b c
a Chemical and Environmental Engineering, Yale University, 17 Hillhouse Ave, New Haven, CT 06511, USA
b Center for Green Chemistry & Green Engineering at Yale, Yale University, 370 Prospect Street, New Haven, CT 06511, USA
c School of the Environment, Yale University, 195 Prospect St, New Haven, CT 06511, USA
d Environmental Studies, Yale College, 1 Prospect St, New Haven, CT 06511, USA
Received 8 April 2024, Revised 23 May 2024, Accepted 23 June 2024, Available online 24 June 2024, Version of Record 27 June 2024.
Abstract
The emerging nutraceutical, fucoxanthin, shows promise as a high-value product to enable the integrated biorefinery. Fucoxanthin can be extracted from algae through supercritical fluid extraction (SFE), but literature does not agree on optimal extraction conditions. Here, a statistical analysis of literature identifies supercritical carbon dioxide (scCO2) density, ethanol cosolvent amount, and polarity as significant predictors of fucoxanthin yield. Novel SFE experiments are then performed using a fucoxanthin standard, describing its fundamental solubility. These experiments establish solvent system polarity as the key knob to tune fucoxanthin recovery from 0% to 100% and give specific operating conditions for targeted fucoxanthin extraction. Further experiments compare extractions on fucoxanthin standard with extractions from Phaeodactylum tricornutum microalgae to elucidate the effect of the algae matrix. Results show selectivity of fucoxanthin over chlorophyll in scCO2 microalgae extractions that was not seen in extractions with ethanol, indicating a benefit of scCO2 to design selective extraction schemes.