Baru (Dipteryx alata Vogel) Oil Extraction by Supercritical-CO₂: Improved Composition by Using Water as Cosolvent

Baru (Dipteryx alata) almond is an emerging nut from the Brazilian savannah, that presents unique flavor and an interesting specialty oil. In this study, we aimed at investigating the effects of pressure, temperature, type (alcohol and/or water), and concentration of polar cosolvent on the extraction yield and tocopherol contents of baru oil obtained by supercritical-CO₂ extraction (SC-CO₂); and to investigate the effect of temperature and pressure on phytosterol, phenolic, and volatile compounds' profile in the oil when H₂O was the cosolvent. Baru oil extracted with SC-CO₂ using alcohol as a cosolvent showed a higher extraction yield (20.5-31.1%) than when using H₂O (4.16-22.7%). However, when 0.3% H₂O was used as cosolvent, baru oils presented the highest γ-tocopherol (107 and 43.7 mg/100 g) and total tocopherol (212 and 48.7 mg/100 g) contents, depending on the temperature and pressure used (50°C and 10 MPa or 70°C and 30 MPa, respectively). Consequently, the lowest pressure (10 MPa) and temperature (50°C) values resulted in baru oils with better γ/α-ratio, and the highest contents of β-sitosterol (107 mg/100 g) and phenolic compounds (166 mg/100 g). However, the highest pressure (30 MPa) and temperature (70°C) values improved the volatile profile of oils. Therefore, although alcohol as a cosolvent improved oil yield, small amounts of H₂O provided a value-added baru oil with either high content of bioactive compounds or with a distinctive volatile profile by tuning temperature and pressure used during SC-CO₂ extraction.