Supercritical Fluid Extraction Extracts Research Articles

Comparison of antimicrobial activities of oregano, lavender, sage, anise and clove extracts obtained by supercritical fluid carbon dioxide extraction and essential oils obtained by hydrodistillation

ABSTRACT The aim of the study was to compare the extraction yields, chemical compositions and antimicrobial activities of essential oils obtained by hydrodistillation (HD) and volatile extracts obtained by supercritical fluid extraction extraction (SFE) from oregano (Origanum onites), lavender (Lavandula angustifolia), sage (Salvia officinalis), anise (Pimpinella anisum) and clove (Syzygium aromaticum). Essential oil compounds (EOCs) of the obtained materials from both techniques (HD and SFE) were determined by GC-MS/FID. Agar well diffusion method was used for the determination of antimicrobial activities on five different foodborne microorganisms (Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli Enterococcus faecalis and Klebsiella pneumoniae). According to the results; extraction yields of SFE were found to be higher than HD for all tested aromatic plants. Active ingredient ratios (carvacrol, camphor, anethole, eugenole and linalol) varied depending on the extraction methods. SFE extracts were higher antimicrobial activity than HD essential oils, except clove extract on E. faecalis.

Green Extraction Approach for Isolation of Bioactive Compounds in Wild Thyme (Thymus serpyllum L.) Herbal Dust-Chemical Profile, Antioxidant and Antimicrobial Activity and Comparison with Conventional Techniques.

The aim of this study was to provide a chemical profile and determine the antioxidant and antimicrobial activity of the essential oil (EO) and lipid extracts of Thymus serpyllum L. herbal dust obtained via conventional (hydrodistillation (HD) and Soxhlet extraction (SOX)) and novel extraction techniques (supercritical fluid extraction (SFE)). In addition, a comparative analysis of the chemical profiles of the obtained EO and extracts was carried out, as well as the determination of antioxidant, antibacterial and antifungal activity of the lipid extracts. According to the aforementioned antioxidant and antimicrobial activities and the monoterpene yield and selectivity, SFE provided significant advantages compared to the traditional techniques. In addition, SFE extracts could be considered to have great potential in terms of their utilization in the pharmaceutical and cosmetic industries, as well as appropriate replacements for synthetic additives in the food industry.

Supercritical Fluid Extraction of Bioactive Components from Apple Peels and Their Modulation of Complex I Activity in Isolated Mitochondria.

Supercritical fluid extraction (SFE) was used to extract bioactive compounds from apple (Malus domestica) peel waste from three different Italian cultivars. The bioactive fractions were extracted applying a temperature of 60 °C and a pressure of 250 bar for 15 min with 20% ethanol as co-solvent, at a flow rate of 2 mL/min. The total polyphenol (TP), anthocyanin (TA), ascorbic acid (AA), and antioxidant activity contents (TACs) were measured, while chromatographic analyses were performed to highlight the differences between the extracts. The Stark cultivar had the highest levels of polyphenols, anthocyanins, and ascorbic acid, while the Royal Gala cultivar showed the highest total antioxidant activity. SFE extracts were then tested for their effect on the mitochondrial NADH-ubiquinone oxidoreductase (Complex I) activity on mitochondria isolated from human embryonic kidney cells (HEK239). The Stark extract showed the most positive response in terms of NADH oxidation. The results obtained in this work highlight the potential of apple peel waste as a source of functional phytocompounds and suggest that Stark cultivar extracts may be exploited for pharmacological applications. This study supports the circular bioeconomy by promoting the use of waste products as a valuable resource.

Antiangiogenic and Anticancer Potential of Supercritical Fluid Extracts from Nutmeg Seeds; In vitro, Ex vivo and In silico studies

Background: Angiogenesis is a vital process of forming new blood vessels that occurs during several normal physiological processes. It plays a substantial role in tumor growth and cancer by supplying oxygen and nutrients for the proliferating tumors. Nutmeg, the dried seed of Myristica fragrans, is known for its therapeutic properties. This study aimed to investigate the antiangiogenic and cytotoxic properties of nutmeg extracts derived by Soxhlet and supercritical fluid extraction (SFE) using in-vitro, ex-vivo, and in-silico studies. Method: Nutmeg anticancer property was evaluated against breast cancer cell MCF7 and colon cancer cell HCT116 using MTT in-vitro assay. The antiangiogenic property was investigated using 3D ex-vivo rat aorta assays. The chemical composition of nutmeg extract was characterized using GC/TOF-MS. Subsequently, the main compounds in the nutmeg extract were analyzed against the angiogenesis-associated molecules (COX-1, VEGFA, HIF, and EGF) by molecular docking and were compared with tamoxifen and 5-fluorouracil. Results: The SFE extracts exhibited higher antiangiogenic properties than the Soxhlet (IC50 31µg/mL). Nutmeg SFE extract exhibited higher cytotoxicity towards HCT116 than MCF7 cells. Several active compounds, including myristicin, eugenol, safrole, and α-asarone were identified in the nutmeg SFE extracts using GC/TOF-MS. Molecular docking revealed strong interactions between these compounds and angiogenesis molecular mediators. Particularly, myristicin blocked COX-1, VEGFA, HIF, and EGF enzymes, indicating possible binding interactions. Conclusion: This study highlights the limitless possibilities of nature's offerings in advancing human health. Nutmeg's potential compounds lie in their binding models, which have proven to be powerful tools against cancer and angiogenesis. Myristicin, α-asarone, safrole, and eugenol work synergistically to induce antiangiogenic effects, making nutmeg a promising natural source of angiogenesis inhibitors for future anticancer therapies. The Molecular docking result confirmed that the inhibition of COX-1, VEGF-A, HIF, and EGF by nutmeg compounds offers great potential in the treatment and prevention of various angiogenesis diseases.

Exploring the Sequential-Selective Supercritical Fluid Extraction (S3FE) of Flavonoids and Esterified Triterpenoids from Calendula officinalis L. Flowers.

One of the many advantages of supercritical fluid extraction (SFE) is the possibility of using it in sequential and selective approaches. This is due to the use of a dynamic extraction mode in addition to the possibility of altering the composition of the modifier during the extraction process. In this study, the optimization of Calendula officinalis L. extraction of non-polar and polar compounds was achieved using three-level Box-Behnken designs (BBD). For non-polar compounds, the factors were pressure, temperature, and EtOH percentage. As for the polar compounds, the three variables were temperature, the total modifier percentage, and H2O added in the modifier as an additive. The recovery of selectively rich extracts in triterpendiol esters and narcissin was possible using a sequential two-step SFE. The first step was performed at 80 °C and 15% EtOH, and the second at 40 °C and 30% EtOH:H2O 80:20 v:v with a total of 60 min of extraction. Additionally, the SFE extraction of non-polar compounds was scaled up on a pilot-scale extractor, demonstrating similar results. Finally, the SFE results were compared to ultrasound-assisted extraction (UAE).

Comparative analysis of flavonoids extracted from Dendrobium chrysotoxum flowers by supercritical fluid extraction and ultrasonic cold extraction

Flowers are by-products of the medicinal plant Dendrobium chrysotoxum, with high yield but low utilization rate. Extracting flavonoids from D. chrysotoxum flowers can not only reduce resource waste but also bring economic benefits. In this study, two green extraction methods, SFE (supercritical fluid extraction) and UCE (ultrasonic cold extraction) were used to extract flavonoids from D. chrysotoxum flowers, and the response surface method (RSM) was used to optimize the extraction conditions. The results showed that on the optimal conditions of SFE (time 90 min, temperature 50 °C, pressure 20 MPa) and UCE (time 30 min, power 400 W, temperature 40 °C, solid-liquid ratio 1:40 (w:v), ethanol concentration 60%), the total flavonoid extraction yield was 2.04% ± 0.02% and 0.64% ± 0.02%, respectively. In vitro, antioxidant activity analysis showed that both extracts had good antioxidant activity, and the antioxidant activity of SFE extract was higher than that of UCE extract. The quantitative determination of flavonoid compounds showed that the content of quercetin, kaempferol, and catechin in SFE extract was significantly higher than that in UCE extract, and the content of ellagic acid in the two extracts was similar. These results indicated that the two green extraction methods improved the resource utilization of D. chrysotoxum flowers, and SFE was more suitable for extracting flavonoids from D. chrysotoxum flowers than UCE.

Quantitative determination of organophosphorus, pyrethroid, and dithiolane pesticide residues in brown rice using supercritical fluid extraction and liquid chromatography-tandem mass spectrometry.

Supercritical fluid extraction (SFE) is a fast, versatile, and solvent-efficient automatic extraction method. Despite its advantages, the results of our proficiency tests imply that the applicability assessments of SFE for pesticide residues were insufficient. In this study, as analytical method using SFE was optimized and validated by testing the incurred and fortified brown rice samples with organophosphorus, pyrethroid, and dithiolane pesticides. Validation study using the incurred sample with etofenprox, fenitrothion, and isoprothiolane was performed by comparing the analytical results obtained using the SFE and solid-liquid extraction with homogenization (SLE), which is a well-validated official multi-residue extraction method. The tests on the fortified samples were also performed for seven pesticide residues, chlorpyrifos, diazinon, O-ethyl O-4-nitrophenyl phenylphosphonothioate (EPN), etofenprox, fenitrothion, isoxathion, and isoprothiolane, at three fortification levels, 0.001, 0.01, and 0.1 mg/kg. In the test on the incurred samples, optimized SFE-to-SLE analytical values (CSFE/CSLE) were in 99.2-100.1%, with RSD lower than 3%. In contrast, the analytical-to-spiked concentrations in the tests on the fortified samples were in 96.4-105.0%, with RSD lower than 8.8%. These results indicate that the proposed SFE method, which is well validated with the incurred brown rice sample, is useful for determining organophosphorus, pyrethroid, and dithiolane pesticide residues in brown rice. The proposed SFE method satisfies EU and Japanese maximum residue limits. The consumption of solvent can be reduced to one-fourth of that of SLE using the proposed SFE method.

Enhancing Nutrient Recovery and Bioactive Compound Extraction from Spirulina through Supercritical Fluid Extraction: Implications for SH-SY5Y Cell Viability.

This work explores the efficiency of supercritical fluid extraction (SFE) to recover minerals, pigments, and antioxidant compounds from the spirulina microalgae. Moreover, the fatty acids and phenolic profiles of the extracts obtained were also investigated, and the effect of the extracts on SH-SY5Y cell viability was tested. The extraction of phycocyanin was improved by SFE compared to conventional extraction, from 2.838 ± 0.081 mg/g dry matter (DM) (control) to 6.438 ± 0.411 mg/g DM (SFE). SFE treatment also improved chlorophyll a and carotenoid recoveries increasing from 5.612 ± 0.547 to 8.645 ± 0.857 mg/g DM and from 0.447 ± 0.096 to 0.651 ± 0.120 mg/g DM, respectively. Regarding minerals, the SFE improved Mg recovery with 77% more than the control extraction. Moreover, palmitoleic, stearic, γ-linolenic, eicosadienoic and eicosatrienoic acids recovery was improved by SFE. Phenolic profiles were identified via triple-TOF-LC-MS-MS. Considering heavy metals, a higher rate of Pb extraction was observed for the SFE extract, while no significant differences were observed for Hg between both extractions. Finally, SFE extract improved cell viability compared to the control extract. Thus, SFE constitutes an interesting tool to sustainably extract high-added-value compounds; however, potential contaminants such as Pb need to be controlled in the resulting extracts.

Supercritical fluid extraction of phenolics from Anisophyllea disticha (Jack) Baill. and evaluation of their antioxidant activities

Background: Anisophyllea disticha (Jack) Baill. (A. disticha) is a species of the Anisophylleaceae family that has undergone the least investigation despite being widely used in folk medicine to cure a wide range of illnesses. Objective: The purpose of this study is to examine the impact of various factors on the supercritical fluid extraction of A. disticha in order to maximise recovery of total phenolic content, antioxidant activity, and polyphenol identification. Method: The total phenolic content (TPC) and antioxidant activities of A. disticha were determined using the supercritical fluid extraction (SFE) method and compared with Soxhlet. Box-Behnken design of response surface methodology was performed to examine the effect of independent variables of SFE such as temperature, pressure, and concentration of ethanol as co-solvent on TPC and antioxidant activities of A. disticha stem extracts. Result: At combined effects of different temperatures, pressure, and co-solvent, the total SFE yield were ranged between 0.65 and 4.14%, which was about half of the Soxhlet extract of 8.75±1.54%. The highest concentration (µg/g) of gallic acid (118.83±1.17), p-coumaric (61.60±0.33), ferulic acid (57.93±1.15), and quercetin (24.16±0.41) were obtained at a temperature of 50 ˚C, the pressure of 25 MPa and co-solvent of 20%, while lowest concentration was found 70 ˚C, 30 MPa, and 20% ethanol. Conclusion: SFE extracts possessed remarkable TPC and concentration of phenolic compounds, indicating superior recovery of compounds. SFE showed more than two-fold higher ferric-reducing antioxidant power compared to Soxhlet with values of 585.32±17.01 mg Fe (II)/g extract and 203.63±16.03 mg Fe (II)/g extract, respectively. SFE demonstrated a potential alternative to the classical solvent extraction methods.

Hibiscus sabdariffa L. leaves as an alternative source of bioactive compounds obtained through high pressure technologies

The aim of the present study was to obtain bioactive compounds from hibiscus leaves through supercritical fluid extraction (SFE) and pressurized liquid extraction (PLE). For SFE, temperature, pressure, and co-solvent were evaluated on extraction yield (X0), content of bioactive compounds and antioxidant activity (AA). For PLE, temperature and solvent composition were evaluated on the same responses. The highest X0 was observed at 60 °C, 300 bar and 15% of co-solvent for SFE, and at 100 °C and ethanol 75% for PLE. For bioactive compounds, different results were observed. For SFE, the best condition was at 60 ºC, 100 bar and 15% of co-solvent, and for PLE at 80 ºC with ethanol 99.5%. Regarding AA, SFE extracts presented highest values at 60 ºC, 100 bar and 5% of co-solvent while PLE presented better results at 60 °C and 99.5%. Chlorogenic acid and quercetin were the main compounds identified in the extracts.

Characterization of phyto-components with antimicrobial traits in supercritical carbon dioxide and soxhlet Prosopis juliflora leaves extract using GC-MS

This study aimed to screen the bioactive compounds from Prosopis juliflora leaf supercritical fluid extract and to assess its antimicrobial properties. Supercritical carbon dioxide and Soxhlet methods were used for extraction. The extract was subjected to Gas Chromatography-Mass Spectrometer (GC-MS) and Fourier Transform Infrared for the characterization of the phyto-components. When compared to soxhlet extraction, more components (35) were eluted by supercritical fluid extraction (SFE), according to GC-MS screening. Rhizoctonia bataticola, Alternaria alternata, and Colletotrichum gloeosporioides were all successfully inhibited by P. juliflora leaf SFE extract, which demonstrated strong antifungal properties with mycelium percent inhibition of 94.07%, 93.15%, and 92.43%, respectively, compared to extract from Soxhlet, which registered 55.31%, 75.63% and 45.13% mycelium inhibition respectively. Also, SFE P. juliflora extracts registered higher zone of inhibition 13.90 mm, 14.47 mm and 14.53 mm against all three test food-borne bacterial pathogens viz Escherichia coli, Salmonella enterica and Staphylococcus aureus respectively. Results obtained from GC-MS screening revealed that SFE is more efficient than soxhlet extraction in recovering the phyto-components. P. juliflora may provide antimicrobial agents, a novel natural inhibitory metabolite.

Antioxidant compounds and eugenol quantification of clove (Syzygium aromaticum) leaves extracts obtained by pressurized liquid extraction and supercritical fluid extraction

This study investigated the efficiency of supercritical fluid extraction (SFE) and pressurized liquid extraction (PLE) to obtain clove leaf extracts. Further, the quality of the extracts in terms of yield, eugenol content, and antioxidant activity was evaluated. In both methods, the temperature had a positive effect on the yield of extract and eugenol. Ethanol extraction with pressurized liquid resulted in the highest extract yields of 3.70% (w/w) at 40 °C, 5.33% (w/w) at 50 °C, and 6.60% (w/w) at 60 °C. The highest total yield resulted from eugenol with 2.66 g per kg of leaves, i.e., 0.266% (w/w). However, the SFE extract yield was 1.94% at 300 bar and 60 °C with a high eugenol yield of 8.06 g per kg of leaves, i.e., 0.806% (w/w). SFE-CO2 demonstrated efficiency for eugenol-rich extracts. PLE and SFE-CO2 showed satisfactory results for antioxidant capacity and content of phenolic compounds.

Comparative study of phytochemical extraction using hydrogen-rich water and supercritical fluid extraction methods

Phytochemicals are widely found in agri-food wastes. The extraction of ‎phytochemicals was evaluated using hydrogen-rich water extraction (HRW-E) and supercritical fluid ‎extraction (SFE) methods from different plant wastes (tomato peel, orange carrot, green ‎apple ‎peel, lemon peel, red cabbage). Total phenolic content (TPC), total ‎flavonoid content (TFC), total anthocyanin, and antioxidant activity (DPPH and ABTS) were ‎highest in HRW-E samples compared to SFE and pure water extraction for all plant wastes. The percent increase (%) ranged between 5.14 and 12.06 and 22.27–49.62 (TPC), 1.32–35.59 and ‎‎16.01-‎‎‎53.03 (TFC), 18.18–53.19 and 80.53–390.1 (anthocyanins), 2.21–22.37 and 9.03-‎‎142.46 ‎‎‎(DPPH), and 1.16–7.49 and 14.47–28.05 (ABTS) for SFE and HRW-E samples, ‎respectively. ‎HRW-E was more potent than SFE for extraction of all phytochemical types from ‎all plant wastes. Non-flavonoids, e.g., phenolic acids (gallic acid, chlorogenic acid, p-‎coumaric acid, trans-ferulic acid‎) and flavonoids (catechin, epicatechin, and rutin)‎, were extracted ‎better by HRW-E than ‎‎SFE for different plant wastes. ‎The HRW-E method is recommended to researchers and processors‎ as an extraction method for phytochemicals due to its simplicity, low cost, not requiring additional equipment or ‎energy source, non-toxic solvent use, green properties of the product and for the environment, as well as higher extraction ‎‎efficiency.‎

Supercritical Fluid Extraction of Oils from Cactus Opuntia ficus-indica L. and Opuntia dillenii Seeds.

This study aimed to assess the capability of supercritical fluid extraction (SFE) as an alternative and green technique compared to Soxhlet extraction for the production of oils from Opuntia ficus-indica (OFI) seeds originating from Yemen and Italy and Opuntia dillenii (OD) seeds from Yemen. The following parameters were used for SFE extraction: a pressure of 300 bar, a CO2 flow rate of 1 L/h, and temperatures of 40 and 60 °C. The chemical composition, including the fatty acids and tocopherols (vitamin E) of the oils, was determined using chromatographic methods. The highest yield was achieved with Soxhlet extraction. The oils obtained with the different extraction procedures were all characterized by a high level of unsaturated fatty acids. Linoleic acid (≤62% in all samples) was the most abundant one, followed by oleic and vaccenic acid. Thirty triacylglycerols (TAGs) were identified in both OFI and OD seed oils, with trilinolein being the most abundant (29-35%). Vanillin, 4-hydroxybenzaldehyde, vanillic acid, and hydroxytyrosol were phenols detected in both OFI and OD oils. The highest γ-tocopherol content (177 ± 0.23 mg/100 g) was obtained through the SFE of OFI seeds from Yemen. Overall, the results highlighted the potential of SFE as green technology to obtain oils suitable for functional food and nutraceutical products.

A Comparative Study on Response Surface Optimization of Supercritical Fluid Extraction Parameters to Obtain Portulaca Oleracea Seed Oil with Higher Bioactive Content and Antioxidant Activity Than Solvent Extraction

AbstractPortulaca oleracea (purslane) seed oil is a rich source of omega‐6 and omega‐3 fatty acids. Extraction of the purslane seed oil while preserving its high nutritive quality has been a challenge since conventional solvent extraction has many adverse effects on bioactive content. This study aims the optimization of purslane seed oil supercritical fluid extraction (SFE) conditions and to compare purslane seed oils obtained with SFE and conventional solvent extraction in terms of oil yield, along with the purslane seed oil quality and bioactive content. For this purpose, the SFE process parameters (pressure, temperature, static time, and dynamic time) are optimized for oil yield, omega‐6, omega‐3, and antioxidant activity using response surface methodology (RSM). Optimum SFE pressure, temperature, static time, and dynamic time levels are determined as 350 bar, 50 °C, 20 min, and 90 min, respectively. Oil yield and physicochemical quality properties of conventional solvent extract and SFE samples are determined and compared. Consequently, samples obtained via SFE and solvent extraction have similar quality properties. Distinctly, SFE allows an extraction with 5.6% higher total phenolic compound (TPC) and 33% higher antioxidant activity than solvent extraction.Practical Applications: In the study, the extraction of purslane oil using supercritical fluid extraction is optimized with different approaches. At optimum conditions, purslane oil is extracted and all physicochemical properties and the process efficiency (yield) are compared with the solvent‐extracted samples. The results of this study make supercritical fluid extraction of purslane seed oil possible since all optimum operating conditions of a pilot‐sized extractor are reported in the study. It is believed that the results provide a good starting point for industrial operations. Moreover, researchers also believe that research studies unveiling the new potential oil‐bearing seeds are important to overcome the vegetable oil shortage that emerged this year.

Attempts to Detect Lipid Metabolites from a Single Cell Using Proton-Transfer-Reaction Mass Spectrometry Coupled with Micro-Scale Supercritical Fluid Extraction: A Preliminary Study.

Proton-transfer-reaction (PTR) mass spectrometry (MS), a widely used method for detecting trace-levels of volatile organic compounds in gaseous samples, can also be used for the analysis of small non-volatile molecules by using supercritical fluid as a transporter for the molecules. Supercritical fluid extraction (SFE) is a method that permits lipophilic compounds to be rapidly and selectively extracted from complex matrices. The combination of the high sensitivity of PTR MS with the SFE is a potentially novel method for analyzing small molecules in a single cell, particularly for the analysis of lipophilic compounds. We preliminarily evaluated this method for analyzing the components of a single HeLa cell that is fixed on a stainless steel frit and is then directly introduces the SFE extracts into the PTR MS. A total of 200/91 ions were observed in positive/negative ion mode time-of-flight mass spectra, and the masses of 11/10 ions could be matched to chemical formulae obtained from the LipidMaps lipids structure database. Using various authentic lipophilic samples, the method could be used to detect free fatty acids in the sub-femtomole to femtomole order in the negative ion mode, the femtomole to sub-picomole order for fat-soluble vitamins, and the picomole order for poly aromatic hydrocarbons in both the positive and negative ion mode.

Isolation of Cherry Seed Oil Using Conventional Techniques and Supercritical Fluid Extraction.

This study aims to compare the suitability of three extraction techniques (cold pressing, Soxhlet and supercritical fluid extraction (SFE)) to isolate oil from cherry seeds. Oils were examined in terms of extraction yield, fatty acids profile, tocopherols yield and antioxidant activity. Additionally, influence of SFE parameters was evaluated using one-factor-at-a-time design with pressure (200-350 bar), temperature (40-70 °C), flow rate (0.2-0.4 kg/h) and particle size (<800 µm and >800 µm). Oil yields ranged from 2.50% to 13.02%, whereas the highest yield was achieved with SFE. Samples were rich in polyunsaturated fatty acids, regardless of the applied extraction technique. The main fatty acids were linoleic (46.32-47.29%), oleic (40.89-41.65%), palmitic (6.56-8.00%) and stearic (2.21-2.30%) acid. Total tocopherols yield was between 16.63 mg/100 g oil and 60.61 mg/100 g oil, and highest yield was achieved with SFE. Among the tocopherols, γ-tocopherol was the most abundant, followed by α-, δ- and β-tocopherol. Antioxidant activity was determined using 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic) cation (ABTS) assays, and the results indicated that SFE extracts exhibited better or comparable antioxidant potential compared to traditional techniques. The comparison between modern and conventional extractions for oil recovery demonstrates pros and cons for the possibility of industrial application.

Supercritical fluid extraction of bioactive compounds from quinilla (Manilkara bidentata) seed

Quinilla seeds (QS) are a potential source of little-known bioactive compounds with high biological values. This work evaluated the supercritical fluid extraction (SFE) of bioactive compounds from QS for the first time, evidencing the relations between pressure and temperature to the extract yield and composition. Pressures from 15 to 35 MPa and temperatures from 313 to 333 K were tested, and the process was modeled based on the principle of mass conservation. The highest SFE yield was 20.0 g extract/100 g QS, achieved at 35 MPa and 313 K. Close values were obtained at 25 MPa-313 K and 35 MPa-323 K. The composition of the extracts varied with the operating conditions, and the three main compounds presented in all extract were squalene, phenol, 2,4-bis(1,1-dimethylethyl)-, and n-Hexadecanoic acid. The SFE extracts of QS present potential applications in the cosmetic and pharmacological industry that require further study. The proposed mathematical model was in excellent agreement with the experimental data, and it was effectively employed to estimate the SFE yield for large-scale SFE plants.

Experimental optimization of the supercritical fluid extraction of triterpenoids from Acacia dealbata Link. Leaves

Acacia dealbata Link. is an invasive species with a negative impact on forest production areas. Its removal generates large amounts of residues (biomass) that can be burned for energy production or extracted to obtain high-value compounds, such as triterpenoids of the lupane, ursane and oleanane families, with known bioactive properties. The extraction can be performed with conventional organic solvents or by supercritical fluid extraction (SFE) with CO2 which is a greener alternative. In this work, SFE of A. dealbata Link. leaves was studied in order to identify and optimize the SFE parameters (pressure: 200–300 bar; temperature: 313.15–353.15 K; and addition of ethyl acetate as cosolvent: 0–10 wt%) that enhance productivity and selectivity towards specific triterpenoids. Even though Soxhlet extraction with dichloromethane provided higher total extraction yield (ηTotal = 3.8 wt% versus 2.1–3.2 wt%, for SFE), SFE surpassed Soxhlet results in terms of individual yields and concentrations of squalene, α-tocopherol, α-amyrone, β-amyrone, and lupenone. For these five compounds the SFE yield reached 0.8043 wt% and the extract concentration reached 35.5 wt% (15.1 % and 95.1 % higher than with Soxhlet extraction, respectively). Particular emphasis should be given to lupenone, with a maximum yield of 0.4748 wt% and a concentration of 22.9 wt% in the SFE extracts obtained at 250 bar, 313.15 K and no cosolvent (ethyl acetate). The optimum conditions of pressure, temperature and ethyl acetate content depended on the response. Productivity, ηTotal, was maximized by increasing all three factors to its maximum conditions. Temperature was one of the most impactful parameters on the individual triterpenoids SFE yields with lower temperatures enhancing the selectivity.

Microscale supercritical fluid extraction combined with supercritical fluid chromatography and proton-transfer-reaction ionization time-of-flight mass spectrometry for a magnitude lower limit of quantitation of lipophilic compounds

The application of proton transfer ionization reaction mass spectrometry (PTR MS) combined with microscale supercritical fluid extraction (SFE) and supercritical fluid chromatography (SFC) aiming to quantitate single-cell fatty acid analysis levels was investigated. Using a microscale extraction vessel, the obtained low limits of quantitation (LLOQs) of arachidonic acid and arachidic acid were 1.2 and 2.7 fmol, respectively, by using less than 1 µL of sample on stainless steel frit. A series of phthalate, vitamin K1, and α-tocopherol were also tested, and the LLOQ was less than one femtomole for phthalate and 35 and 13 fmol for vitamin K1 and α-tocopherol, respectively. A microliter portion of SFE extracts was introduced into the SFC column by split injection, improving the reproducibility of the chromatography and separation efficiency. The method in the present study has great potential to quantitate lipophilic molecules on the nanogram scale of a sample without complex preparation procedures.