Effect of Temperature and Molarity on the Evaluation of Antimicrobial, Cytotoxic, and Antioxidant Activities of the Bio-Oil from Açaí Seed (Euterpe oleracea Mart.)

Açaí (<i>Euterpe oleracea</i> Mart.), a fruit from the Amazon, is valuable both economically and nutritionally. Its seeds, often discarded, can be transformed into bio-oil through pyrolysis (a thermochemical degradation process of residual biomass), providing a sustainable alternative to fossil fuels. This study investigates how temperature and molarity influence the antimicrobial, antioxidant, and cytotoxic activities of the produced bio-oil. Various assays were performed on bio-oil samples obtained under different pyrolysis conditions-specifically, at temperatures of 350, 400, and 450 °C, and molarities of 0.5 M, 1.0 M, and 2.0 M-to evaluate antimicrobial, antioxidant, and cytotoxic activities. Gas chromatography-mass spectrometry (GC-MS) was used to analyze the composition, revealing that phenolic compounds were the most abundant (55.70%), followed by cyclic and aromatic hydrocarbons (11.89%), and linear hydrocarbons (9.64%). Despite a reduction in oxygenated compounds, the bio-oil maintained bacteriostatic activity against <i>Escherichia coli</i> and <i>Staphylococcus aureus</i>, especially at 350 °C. The antioxidant activity was highest at 350 °C and at lower molarities. Additionally, lower concentrations of acid impregnation showed cytotoxic effects at higher temperatures. Thus, bio-oil from açaí seeds produced via pyrolysis demonstrates potential for antioxidant and antimicrobial activities, suggesting viability for further testing at dilutions with lower cytotoxicity.