Avaliação da extração e caracterização do óleo de jojoba por solventes alternativos

Abstract

The search for sustainable methods for extracting vegetable oils motivated this study, which aimed to evaluate the extraction and characterization of jojoba oil (Simmondsia chinensis) using alternative solvents. Extractions were carried out employing the ionic liquid 1-butyl-3-methylimidazolium bromide ([Bmim][Br]), acetone, 1,4- dioxane, and binary mixtures of acetone/ethanol (1:1) and 1,4-dioxane/water (1:1). Extractions with organic solvents were performed in a Soxhlet system for 8 hours with an average dripping rate of 3 drops per second, while the ionic liquid was heated at 80°C under constant stirring. The obtained samples were characterized by Fourier-transform infrared spectroscopy (FTIR) and evaluated for antioxidant activity using the DPPH method. The ionic liquid showed no extraction efficiency, as its spectra were identical to those of the pure solvent, indicating the absence of lipid compounds. Among the organic solvents, acetone exhibited the best performance, with an average yield of 63% and the presence of the main bands associated with the esters of jojoba oil, including C–H stretching (2920 and 2850 cm⁻¹), ester C=O stretching (1735 cm⁻¹), and C–O vibrations (1180 and 1032 cm⁻¹), in addition to presenting a Trolox equivalent antioxidant capacity of 50.72 μg mL⁻¹. The binary mixtures showed lower yields and antioxidant activity below the detection limit. Overall, the results indicate that pure acetone represents a viable and lower-impact alternative compared to hexane, with good potencial for jojoba oil extraction.