Green extraction of carotenoids and oil produced by Rhodosporidium paludigenum using supercritical CO2 extraction: Evaluation of cell disruption methods and extraction kinetics

The constantly expanding functional food market has steered scientific research towards alternative sources of bioactive compounds. Red yeasts are valuable producers of active ingredients such as carotenoids and microbial oil. Efficient and sustainable recovery methods are required when food applications are targeted. In this study, intracellular carotenoids and oil synthesized by Rhodosporidium paludigenum in batch bioreactor cultures were recovered using supercritical CO₂ (SFE-CO₂) as a green alternative to conventional organic solvents. Yeast biomass was subjected to six different cell disruption methods prior to SFE-CO₂. Homogenization emerged as the optimal pre-treatment method, resulting in an 80 % yield of total carotenoids and an 83 % yield of microbial oil. The use of ethanol as co-solvent was imperative for the efficient recovery of both products. β-Carotene was the main carotenoid, while the obtained microbial oil was rich in oleic acid. These results pave the way for integrating these functional compounds into innovative food products.