Sequential extraction of chalcones from Libidibia ferrea Mart. fruits by green pressurised fluids

The phenolic compounds, such as chalcones, present in Libidibia ferrea Mart. are known for their therapeutical activities of this plant. In this study, sequential extraction was investigated for the first time as a method for extracting chalcones from L. ferrea fruits. Supercritical CO₂ was used in the first extraction step, followed by sequential CO₂-expanded liquid extractions with water, ethanol, and acetone, each modified with a mass fraction of 10 % CO₂, at temperatures ranging from 308 K to 328 K, pressure between 14 MPa and 40 MPa, and solvent densities from 620 kg/m³ to 1011 kg/m³ . The effects of pressure, temperature, solvent density, and extraction solvent type on the global yields of sequential extraction and chalcone content in the extracts were studied. Results demonstrated that the sequential extraction approach effectively recovered up to 20 % of chalcones in the final step, where CO₂-expanded liquid acetone was used as a solvent. The collected data were modelled, and optimisation and robustness studies were conducted to determine the optimal extraction parameters for maximizing chalcone content and extract yield while minimizing chalcone extraction in earlier steps. Additionally, Monte Carlo simulations were applied to evaluate the process control limits for the optimal conditions of maximization of chalcones and extract yield. This work employed a tuneable, versatile, and selective extraction method based on the sequential use of different pressurized solvents to extract chalcones from L. ferrea fruits.