TOWARDS A BIO-BASED EXTRACTION PROCESS FOR BRAZIL NUT (Bertholletia excelsa) PRESS CAKE ANTIOXIDANTS: THERMODYNAMIC EVALUATION OF ECO-FRIENDLY SOLVENTS.

The oil extraction of Brazil nuts (Bertholletia excelsa) yields a residual cake rich in macronutrients and nutraceuticals, including tocopherols and phytosterols. To valorize this byproduct, the recovery of bioactive compounds can be achieved via eco-friendly solvents, such as ethanol and eutectic bio-solvents, leveraging their established efficiency in plant biomass extraction. This study aimed to evaluate, through thermodynamic computational simulation, the potential of the terpene-based solvents combined with ethanol to extract antioxidants, compared with experimental results. Solvents were screened via COSMO-SAC to predict sigma profiles and infinite dilution activity coefficients for the major target solutes: γ-tocopherol, β-sitosterol and gallic acid. The extraction systems consisted of pure L-carvone and DL-menthol, as well as their binary blends with each other or with acetic acid (1:1 molar ratio). These were evaluated either alone or combined with ethanol in various concentrations at 60 °C. Simulation-optimized solvents were used for experimental antioxidant extraction from Brazil nut press-cake (1:4 solid:solvent, 200 rpm, 60°C, 4h) following established literature. Extracts were quantified for total lipids content, tocopherol profile, total phytosterol content, total polyphenol content (TPC), antioxidant capacity using DPPH free radical scavenging assay (IC₅₀). Additionally, extraction yield, distribution coefficients, and selectivity were determined. Morphological changes in the defatted solids were assessed via Scanning Electron Microscopy (SEM). While computational simulations predicted extraction capacities comparable to pure ethanol due to strong molecular interactions, experimental results demonstrated that the terpene-ethanol association significantly outperformed pure ethanol in a single-batch process. These findings suggest that terpenes are efficient green alternatives for enhancing extraction performance.