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This study aimed to determine the optimal pressure and temperature for the maximum extraction yield and recovery of lipophilic bioactive compounds (BACs) during the supercritical carbon dioxide extraction (SCO2) of fennel seeds. For this purpose, the SCO2 pressure (78.6–361.4 bar) and temperature (35.9–64.1 °C) were varied and optimized, and all of the extracts obtained were analyzed for the volatiles, fatty acids, sterols, tocochromanols and carotenoids. The results showed that the maximum extract yield and content of all of the compounds analyzed favored a higher pressure (320 bar) and lower temperature (40 °C), except for the volatiles, which were the highest at 120 bar and 42 °C. However, the optimal SCO2 conditions for obtaining the highest overall total lipophilic fraction were 320 bar and 40 °C, respectively. The fennel SCO2 extract obtained under these conditions contained 18 volatiles (trans-anethole as the major component), 12 fatty acids (oleic and petroselinic as the major compounds), 12 sterols (β-sitosterol and stigmasterol as the major compounds), two pentacyclic triterpenoids (α-, β-amyrin), one tocopherol (α-tocopherol), two tocotrienols (γ-, δ-tocotrienol) as well as two carotenoids (lutein and β-carotene). The SCO2 proved to be very efficient for the isolation of various lipophilic BACs from fennel, and the results of this study may be of interest to academia and industry. [ABSTRACT FROM AUTHOR]

Pretreatment of grape pomace seeds with a pulsed electric field (PEF) was applied to improve the extraction yield of cold-pressed grape seed oil. The effects of different PEF conditions, electric field intensities (12.5, 14.0 and 15.6 kV/cm), and durations (15 and 30 min) on the oil chemical composition were also studied. All PEF pretreatments significantly increased the oil yield, flow rate and concentration of total sterols (p < 0.05). In addition, similar trends were observed for total tocochromanols and phenolic compounds, except for PEF pretreatment under the mildest conditions (12.5 kV/cm, 15 min) (p < 0.05). Notably, the application of 15.6 kV/cm for 30 min resulted in the highest relative increase in oil yield and flow rate (29.6% and 56.5%, respectively) and in the concentrations of total tocochromanols, nonflavonoids, and flavonoids (22.1%, 60.2% and 81.5%, respectively). In addition, the highest relative increase in the concentration of total sterols (25.4%) was achieved by applying 12.5 kV/cm for 30 min. The fatty acid composition of the grape seed oil remained largely unaffected by the PEF pretreatments. These results show that PEF pretreatment effectively improves both the yield and the bioactive properties of cold-pressed grape seed oil. [ABSTRACT FROM AUTHOR]

Background: Myrtle (Myrtus communis L.) is a coastal Mediterranean aromatic medicinal plant rich in essential oil components, flavonoids, and phenolic acids. Studies highlight the potential health benefits of myrtle bioactive compounds with antioxidant and antiproliferative properties. Since limited research exists on myrtle fruit's lipid fraction, the aim of this study was to apply supercritical CO2 extraction to obtain bioactive compounds from myrtle berries focusing on the fatty acids, sterols, and essential oils. Methods: The optimization of the supercritical CO2 extraction of myrtle fruit using CO2 as solvent was carried out using the response surface methodology with Box–Behnken experimental design. The following conditions were tested: temperature (40, 50, and 60 °C), pressure (200, 300, and 400 bar), and flow rate (20, 30, and 40 g min−1) on the yield of lipid extract as well as on the yield of fatty acids, phytosterols, and volatiles present in the extract and constituting its bioactive potential. Results: In the extracts examined, 36 fatty acids, 7 phytosterols, and 13 volatiles were identified. The average yield of the extract was 5.20%, the most abundant identified fatty acid was essential cis-linolenic acid (76.83%), almost 90% of the total phytosterols were β-sitosterol (12,465 mg kg−1), while myrtenyl acetate (4297 mg kg−1) was the most represented volatile compound. The optimal process conditions obtained allow the formulation of extracts with specific compositions. [ABSTRACT FROM AUTHOR]

This study compared the efficiency of advanced supercritical CO2 extraction (SC-CO2) and conventional Soxhlet extraction (SE) in the isolation of lipophilic bioactive molecules (BAMs) from the oils of different sea buckthorn (SB) berries (Leikora and Ascola). A SB cake, a valuable by-product of oil extraction, was analyzed for phenolic compounds and antioxidant activity (AA). For this purpose, ultrasound-assisted extraction (UAE) with 70% (v/v) ethanol was optimized, and the following optimal UAE conditions were determined: ultrasonic power of 60%, temperature of 50 °C, and extraction time of 20 min. The individual BAMs in the oils and cake extracts were analyzed chromatographically, while the AAs were determined using the ORAC method. The oils extracted with SC-CO2 had a higher content of lipophilic BAMs and a higher AA value than the oils extracted with SE. Palmitic and palmitoleic acids, β-sitosterol, and α-tocopherol dominated the Leikora oil, while a higher content of oleic, linoleic, and α-linolenic acids and carotenoids was found in the Ascola oil. The highest phenolic content was found in the Ascola cake, with the flavonols isorhamnetin-3-hexoside, isorhamnetin-3-rutinoside, and quercetin-3-glucoside being the most abundant. Oil and cake extracts of the Ascola variety also had a higher AA. [ABSTRACT FROM AUTHOR]