Sustainable Valorization of Amazonian Pracaxi (Pentaclethra macroloba (Willd.)) Residues via Optimized Ultrasound-Assisted Extraction of Bioactive Compounds

Pracaxi is an Amazonian oil widely valued in industry for its biological properties. However, its processing generates a biomass that is frequently accumulated without adequate disposal. This material is a source of phytochemicals with high biological activity. Design of Experiments (DOE) is a useful approach for optimizing processes by controlling influencing variables without the need for numerous tests. This work aimed to optimize the ultrasound-assisted extraction of bioactive compounds (Total phenolic compounds -TPC, Total flavonoids- TF and antioxidant activity—AA) from pracaxi biomass residue through an axial 23 experimental design, with desirability function and Response Surface Methodology (RSM), the effects studied were: extraction time in ultrasound (min) (x1), solid-liquid ratio (% m/v) (x2) and ethanol concentration (% v/v) (x3), the dependent variables were TPC, TF and AA. The experimental design revealed that variables with the most significant effect in this study were x2, followed by x3 and x1. The theoretical optimal condition was achieved using the desirability function, yielding an overall value of D = 71.57%, under the following conditions: 0.85 mg GAE/g for TPC, 0.028 mg QE/g, and 92 µmol ET/g of sample. The experimental values obtained achieved error values of 10.23%, 3.57% and 13.28%, respectively. These results indicate that the obtained model can be considered satisfactory. The use of ethanol with ultrasound-assisted extraction is an efficient and economically viable technique for obtaining bioactive compounds from pracaxi, offering the potential to valorize a residue from the Amazon and contribute to the circular economy.