PRESSURIZED LIQUID EXTRACTION (PLE) OF BIOACTIVE COMPOUNDS FROM TUCUMÃ-DO-AMAZONAS (Astracaryum aculeatum) PEEL

Tucumã-do-Amazonas (Astrocaryum aculeatum) is a fruit native from the Amazon region, very appreciated for its fresh pulp by the local people. Since the pulp is the mainly consumed part, by-products like the almond and peel are generated, even containing significant amounts of oil, protein, and bioactive compounds such as phenolics. This work aimed to extract bioactive compounds from the defatted tucumã-do-Amazonas peel (TAP) using pressurized liquid extraction (PLE). TAP was previously defatted by supercritical CO₂ extraction at 35 MPa and 40 °C. PLE was performed with ethanol-water mixtures (50%, 75%, and 100% ethanol, w/w) at different temperatures (100, 125, and 150 °C) and pressure of 10 MPa, resulting in a total of 18 experiments. The PLE global yield was calculated as the mass ratio between dry extract and defatted TAP. The total reducing capacity (TRC) was measured using the Folin-Ciocalteu reagent, and antioxidant capacities were evaluated using ORAC and FRAP methods. Global yields ranged from 9.7 to 21.62 g extract/100 g defatted TAP, with the highest yields achieved with 75% ethanol, showing no significant difference between the evaluated temperatures. The TRC was also the highest in the extract obtained with 75% ethanol, between 37.27 and 42.84 mg GAE/g defatted TAP. The FRAP results followed the same trend, whereas the greatest ORAC was obtained at 150 °C with the same solvent composition. This work highlights that solvent mixtures can improve extraction efficiency by enhancing solubility and interaction with the compounds, with water helping to break bonds between the matrix and solute. Overall, PLE is a promising method for obtaining extract rich in bioactive compounds from TAP.