Optimizing Phenolic Compounds Extraction from Jatobá Fruit Husk Using a Mixture Design Approach

Jatobá is a fruit-bearing plant whose pod husk accounts for approximately 70% of the fruit weight, becoming a residue after consumption or processing. Recent studies indicate that this byproduct is a promising source of phenolic compounds. However, extraction process variables, particularly solvent composition, can significantly impact recovery yields, although their effect remains poorly understood. In this context, a simplex-centroid mixture design was applied to optimize the solvent system to maximize the extraction of phenolic compounds and antioxidants from jatobá fruit husk. Different combinations of water, methanol, and acetone were evaluated using TPC, ABTS, and FRAP as response variables. Statistical analyses confirmed the significance of the models, with no lack of fit and high coefficients of determination. Multi-response optimization using the desirability function identified a nearly equivalent mixture of water and acetone (51.52%:48.48%, water/acetone) as the optimal condition, yielding predicted values of 41.51 mg GAE/g dw (TPC), 340.36 µmol TE/g dw (ABTS), and 485.74 µmol TE/g dw (FRAP), which did not differ statistically from the experimental values obtained in the validation assay (40.64 mg GAE/g dw for TPC, 334.31 µmol TE/g dw for ABTS, and 482.69 µmol TE/g dw for FRAP). HPLC-DAD analysis revealed that the fruit husk is predominantly composed of monomeric and dimeric procyanidins, especially epicatechin and procyanidin B2. Overall, these findings demonstrate the effectiveness of mixture design in optimizing extraction conditions and highlight jatobá fruit husk as a promising byproduct for the sustainable obtention of phenolic compounds and antioxidants with potential applications in products intended for human consumption after security validation.