Ultrasound-Assisted Green Extraction of Phenolic Compounds from Astrocaryum murumuru Biomass

Astrocaryum murumuru Mart., an Amazonian oilseed widely used for cosmetic oil production, generates large amounts of residual biomass that remains underexplored. In this study, ultrasound-assisted extraction (UAE) with ethanol as a green solvent was optimized using a Central Composite Rotational Design (CCRD) with 2 levels (23) and 3 independent variables. The optimal condition (60 % ethanol, solid–liquid ratio 2.5 % m/v, 26 min) was determined using response surface methodology (RSM), and yielded 9.92 mg GAE/g of total phenolic content (TPC), with an experimental error of 5.34 % compared to the theoretical model prediction. Under this condition, total flavonoids and tannins were also quantified, reaching 0.38 ± 0.01 mg QE/g and 4.03 ± 0.10 mg TA/g, respectively. LC-MS analysis revealed a complex phenolic profile within the extract, confirming the efficiency of UAE in recovering bioactive molecules. Biological assays revealed significant functional properties. Antioxidant activity, evaluated by ABTS and DPPH methods, indicated that the extracts were effective radical scavengers. Antimicrobial assays showed only growth-selective inhibition against Staphylococcus aureus at concentrations of 2.5–20 mg/mL, while no significant activity was observed against Escherichia coli and Pseudomonas spp. These findings highlight the potential of A. murumuru biomass residues as a sustainable source of bioactive compounds with antioxidant activity and a growth inhibitor of S. aureus, reinforcing their possible application in the development of natural additives for food, while contributing to the sustainable bioeconomy of the Amazon.