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 ß-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.

Hass avocado (Persea americana Mill.) oil enriched in phenolic compounds and tocopherols by expeller-pressing the unpeeled microwave dried fruit.

This study investigated how the quality of avocado oil is affected by the fruit ripening stage and peeling, and the drying process used. Expeller pressed avocado oils were obtained from unripe or ripe pitted avocados after drying peeled or unpeeled pulps by convection oven, microwave or freeze-drying. Oils from the unpeeled microwave dried pulp (from unripe or ripe avocados) showed the highest induction period (54.2-83.6 h) and antioxidant capacity (4.07-5.26 mmol TE/kg), and high amounts (mg/100 g) of α-tocopherol (11.6-21.0), ß-carotene (0.49-0.65) and chlorophyll (44.3-54.0), and unsaponifiable matter (2.48-2.99 g/100 g). Pulp drying process and avocado (un)peeling were the major contributors to the induction period (R2 = 0.61; p = 0.0139) and antioxidant capacity (R2 = 0.62; p = 0.011), and the oils from microwave dried unpeeled pulp were those that presented the best performance. The phenolic composition of these oils improved with ripening and keeping the peel during the pressing process.