Subcritical CO2 Extraction Research Articles

Study of the chemical components of CO2 extracts from the fruits of Sorbus aucuparia L.

The article presents the results of the study of the chemical composition of Sorbus aucuparia L. СО2 subcritical extract. For the first time in Kazakhstan, 20 grams of brown Sorbus aucuparia L. extract were collected using subcritical carbon dioxide extraction. The current study was directed mainly to the chemical compositions of subcritical Sorbus aucuparia L. СО2 subcritical extract. The Sorbus aucuparia L. extract's chemical compositions were determined using gas chromatography/mass spectrophotometry (GC-MS). The extract included the following main compounds: 5-Methyl-2(3H)-furanone (30.18 %), 5-(3-Ethoxy-4,5-dihydro-isoxazol-5-yl)-5-methyl-imidazolidine-2,4-dione (3.20 %), 4H-Pyran-4-one, 2,3-dihydro-3,5-dihydroxy-6-methyl (2.53 %). Determined fatty acid profile and the moisture content of raw vegetable ingredients of Sorbus substance. Quantitative determination of fatty acids of ethanol extract was carried out. The results of the analysis for fatty acids in the study showed that linoleic (37.7 %) and oleic (50.5 %) were the most prominent fatty acids. The aim of this study is to determine the component composition by using the GC-MS method and fatty acid to study the Sorbus aucuparia L. extract obtained by CO2 extraction, which grows in Kazakhstan. Materials and methods. To determine the possibility of using Sorbus aucuparia L., we carried out the composition and fatty acid of the extract obtained by CO2 extraction in subcritical conditions of Sorbus aucuparia L. by a certain GC-MS method. Results. The raw materials of the plant were collected in accordance with GACP requirements. Conducted subcritical CO2 extraction of plant raw materials showed a 20 g extraction yield. Chemical compounds were discovered, bioactive components were identified, such as 5-Methyl-2(3H)-furanone (30.18 %), 5-(3-Ethoxy-4,5-dihydro-isoxazol-5-yl)-5-methyl-imidazolidine-2,4-dione (3.20 %), 4H-Pyran-4-one, 2,3-dihydro-3,5-dihydroxy-6-methyl (2.53 %). Conclusions. The possibility of using the obtained CO2 extract of Sorbus aucuparia L. in the field of pharmaceutical products as a substance and a drug

Component composition and antimicrobial activity of subcritical CO2 extract of Ferula asafoetida L., growing in the territory of Kazakhstan

Ferula asafoetida L. has been studied for centuries by many scientists as food products and in traditional medicine, which are relevant for Kazakhstan as well. Recent studies have shown that Ferula asafoetida L. has neuroprotective, memory-enhancing, digestive enzymatic, antioxidant, antispasmodic, hypotensive, hepatoprotective, antimicrobial, antitumor, cytotoxic, and anthelmintic effects. The aim of this study is to determine the component composition by GC-MS method and to study the antimicrobial properties of Ferula asafoetida L. extract obtained by CO2 extraction, which grows in Kazakhstan. Materials and methods. To determine the possibility of using Ferula asafoetida L., we carried out the component composition of the extract obtained by CO2 extraction in subcritical conditions of the underground part of Ferula asafoetida L. by a certain GC-MS method and also investigated the antimicrobial effect of this extract. Results. The plant raw materials were collected in accordance with GACP requirements. Conducted subcritical CO2 extraction of plant raw materials showed a 2.5% extraction yield. The study of the component composition by GC-MS revealed 46.3% of sulfate compounds. The determination of antimicrobial activities showed high efficacy against gram-positive (Staphylococcus aureus subsp. Aureus, Bacillus subtilis subsp. Spizizenii), gram-negative bacteria (Escherichia coli, Klebsiella pneumoniae subsp. pneumoniae, Salmonella enterica subsp. enterica) and fungi (Candida albicans, Aspergillus niger). Conclusions. The possibility of using the obtained CO2 extract of Ferula asafoetida L. in the field of pharmaceutical products as a substance and a drug that has a huge antimicrobial effect

Extraction of hops pelletized (Humulus lupulus) with subcritical CO2 and hydrodistillation: Chemical composition identification, kinetic model, and evaluation of antioxidant and antimicrobial activity

Hop essential oil and hop extract using carbon dioxide (CO2) are products with high added value because they have bioactive and sensory properties. In this context, the objective of this study was to obtain and characterize essential oil and extracts from pelleted hops of El Dorado, Polaris, Hallertau Blanc and Callista varieties using hydrodistillation and subcritical CO2 extraction methods. Extraction yield ranged from 0.38 % to 1.97 % (m/m) for essential oils and from 8.76 % to 15.35 % (m/m) for extracts using subcritical CO2. The chemical compositions of the essential oils were mainly monoterpene (18.14 % to 29.91 %) and sesquiterpene (46.01 % to 59.03 %) hydrocarbons and for the extracts were sesquiterpene hydrocarbons (33.05 % to 71.90 %) and oxygenated sesquiterpenes (14.80 % to 34.89 %). The extracts showed better antioxidant activity than essential oils due to the presence of phenolic compounds and flavonoids. Hop extracts showed some antimicrobial activity, but essential oils did not demonstrate antimicrobial potential. Hop extracts obtained with subCO2 have the potential to be used in the brewing industry as a flavoring and as natural antioxidants.

Bioactive Compounds Extracted from Saudi Dates Using Green Methods and Utilization of These Extracts in Functional Yogurt

The bioactive compounds of four Saudi date flesh extracts (Ambara (AF), Majdool (MF), Sagai (SF), and Sukkari (SKF)) prepared using different extraction methods-namely, supercritical fluid extraction (SFE), subcritical CO2 extraction (SCE), and Soxhlet extraction (SXE)-were evaluated. A total of 19 bioactive compounds were detected in extracts prepared using SFE and SCE methods, whereas less than 12 compounds were detected in extracts obtained using the SXE method. Both the date variety and extraction method affected the phenolic profile of date flesh extract (p ≤ 0.05). The apparent viscosity, surface color, and bioactive properties of yogurt were affected by both date flesh extracts and storage duration in varied magnitudes (p ≤ 0.05). The incorporation of date flesh extracts into yogurt formulations increased the total phenolic content (TPC), DPPH antiradical activity, viscosity, and redness (a*) and decreased the lightness (L*) and yellowness (b*) of the developed product (p ≤ 0.05). The elongation of storage time progressively (p ≤ 0.05) reduced the pH, TPC, DPPH antiradical activity, bacterial counts, and L* and b* values and increased the acidity, syneresis, viscosity, and a* values with few exceptions. Date flesh extracts can improve the health quality of yogurt without major influence on the sensory attributes while stored at 4 °C.

PLANT EXTRACTS AS BIOFUNGICIDES AGAINST SOIL-BORNE PATHOGEN ALTERNARIA SPP.

In the presence of a warmer climate, increase the comparative abundance of fungal plant pathogens. Many of the most aggressive plant pathogens are soil-borne fungi. Alternaria species threaten food security as the chemical fungicides currently used against them are mostly ineffective because of the acquired resistance to active compounds. Broadleaf plantain (Plantago major L.) and rosemary (Rosmarinus officinalis L.) extracts, obtained by subcritical CO2 extraction, were tested for their antifungal activity to investigate the possibility of their use for sustainable plant protection. The ability of the two plant extracts to inhibit mycelial growth was studied by in vitro assay on agar medium containing different concentrations of the tested extracts (200-1000 μL L-1). Alternaria spp. isolate was transferred on the modified medium to test the extracts antifungal activity by calculating the average colony growth after 5 and 7 days. Results showed that rosemary extract had an apparent reducing effect on fungal growth that was dose-dependent. Because of this, it can be considered a potential alternative natural fungicide to the synthetic chemicals currently used to prevent and control soil-borne diseases.

Identification and Determination of the Components of Garden Sage (Salvia officinalis L.) Essential Oil, Isolated by Different Extraction Methods

We studied the component composition of the essential oil of garden sage (Salvia officinalis L.), obtained by various extraction methods. Essential oils were obtained by hydrodistillation and subcritical CO2 extraction, supercritical fluid extraction, and subcritical extraction with solid-phase and liquid–liquid preconcentration. The components were identified by comparing the recorded mass spectra with the spectra of individual compounds and the data of the NIST07 and WILEY8 data bases. For all extraction methods, the major essential oil components were 1,8-cineole, camphor, α-thujone, β-thujone, borneol, 4-terpineol, β-caryophyllene, β-caryophyllene oxide, and viridiflorol. The concentration of analytes in the extracts varied depending on the extraction method. In total, 104 components were identified in the extracts, of which 30 were extracted by hydrodistillation, 32 by subcritical CO2 extraction, 14 by supercritical fluid extraction, 46 and 62 by subcritical extraction with solid-phase and liquid–liquid extraction into the organic phase. An increase in the number of components in more stringent extraction methods as compared to hydrodistillation showed that, in the extracts, a deeper decomposition of macrocomponents might take place, except for camphor.

Fractionation of phytocannabinoids from industrial hemp residues with high-pressure technologies

Cannabidiol (CBD) and cannabidiolic acid (CBDA)- rich extracts were obtained from industrial hemp threshing residues by sub- and supercritical carbon dioxide extraction. The supercritical CO2 extraction yielded 2.5–9.2 g/100 g of lipophilic raw extracts containing 0.2–1.8 g of cannabinoids per 100 g of various threshing residues. Carrying out the supercritical extraction with fractionation, the extract from the 1st separator (operated at 8 MPa and 40 °C) contained 30 times more CBD than the extract from the 2nd separator. Applying ethanol cosolvent to scCO2 in 10% (w/w) increased the extraction yield and the yield of main cannabinoids by 30%. Subcritical CO2 extraction resulted in a yield of 2.5 g/100 g dry material with high CBD content (0.9 g/100 g dry threshing residue) in an extract with less complexity and produced with 18% less solvent usage at mild conditions (8 MPa and 27 °C). The recovery of high cannabinoid-content extracts from industrial hemp residues makes this waste suitable for producing value-added extracts for either cosmetic or food industry.

Poly(butyl acrylate) gel prepared in supercritical CO2: an efficient recyclable oil-absorbent

Oil-absorbing resins containing cross-linked poly(butyl acrylate) (PBA) were synthesized via precipitation polymerization in an environment-friendly route using supercritical carbon dioxide as the reaction media. The PBA resins were then regenerated through subcritical CO2 extraction process. The PBA resins with macroporous structures, prepared at pressures ranging from 17.5 to 24.5 MPa, were characterized by field emission scanning electron microscopy and mercury porosimetry. These structures are beneficial to oil absorption. Thermogravimetric analysis results showed that the PBA resin has good thermal stability. The effect of reaction pressure, initiator ratio, cross-linker content, and absorption time on yield and oil absorption was also investigated. The results revealed a slight decrease in yield with increasing pressure, within a pressure range of 17.5–24.5 MPa. The high initiator concentrations did lead to the decrease in the oil absorption capacity of the PBA resin. A higher product yield of 55% is acquired in the presence of the higher cross-linker content of 20 wt%. The highest absorption capacity of diesel oil onto the PBA resin was 7.5 g/g with oil retention capacity of 95.2%. Moreover, oil desorption of oil-saturated PBA resin was conducted with carbon dioxide instead of the traditional extraction solvents. After 10 repetitions, PBA resin exhibited good recyclability.

Sub-critical CO2 extraction of volatile flavour compounds from ghee and optimization of process parameters using response surface methodology

The volatile flavor compounds of ghee were isolated using sub-critical CO2 extraction. The effect of extraction pressure (3 to 8 MPa), temperature (3 to 38 °C), and time (19 to 221 min) on the extractability of flavor compounds i.e., δ-dodecalctone (C12), δ-tetradecalctone (C14), 3-ethyl-3-methyl heptane and total extraction yield as response variables were studied. The experiments were conducted using a central composite rotatable design of the independent variables. The study revealed that the pressure had a positive effect on the extractability of all three compounds. The optimized sub-critical CO2 extraction pressure, temperature and time for maximum recovery of these compounds were observed at 7 MPa, 10 °C and 66 min, respectively. The values of yields of δ-dodecalctone (C12), δ-tetradecalctone (C14), 3-ethyl-3-methyl heptane, and total extraction yield at the optimized conditions were found to be were found to be 216.54, 109.7, 64.82 ng .g−1 and 5.89% (w/w), respectively.

Characterization of Virgin Avocado Oil Obtained via Advanced Green Techniques

The quality characteristics, bioactive phytochemicals, volatile compounds, and antioxidant capacities of virgin avocado oil extracted using a couple of green methods, namely, subcritical CO2 extraction (SCO2) and ultrasound‐assisted aqueous extraction (UAAE), are compared with the oil extracted using the conventional solvent extraction. Results indicate the quality properties of avocado oil are unaffected by extraction methods. The total phenolic content of avocado oil is in the range of 111.27–130.17 mg GAE/100 g and the major phytosterol is β‐sitosterol (1.91–2.47 g kg−1). Avocado oil extracted using SCO2 exhibits two to four times greater levels of α‐ and γ‐tocopherols than solvent extraction and UAAE. The volatile components associated with nutty and grassy flavors are only detected in avocado oil extracted under low‐temperature extraction conditions such as SCO2 and UAAE. Based on the antioxidant capacity tests, avocado oil obtained by SCO2 exhibits the strongest antioxidant capacity compared with solvent extraction and UAAE.Practical Applications: Virgin avocado oil extracted using subcritical CO2 method exhibits superior levels of tocopherols content and antioxidant capacity than ultrasound‐assisted aqueous and conventional solvent methods. Subcritical CO2 is a promising oil extraction technique to obtain solvent‐free avocado oil with potential uses in functional foods and health care products.Virgin avocado oil is extracted using subcritical CO2 and ultrasound‐assisted aqueous techniques. The properties of the oil are compared with conventional solvent‐extracted oil. The percentage of antioxidant activity decreases in the order of SCO2‐extracted oil > solvent‐extracted oil > UAAE‐extracted oil.

Comparison of subcritical CO2 and ultrasound-assisted aqueous methods with the conventional solvent method in the extraction of avocado oil

Avocado (Persiana americana Mill) belongs to the Lauraceae family. High level of lipids in the avocado pulp can be served as an important raw material for edible oil extraction. In the present study, the physicochemical properties of avocado oil extracted using subcritical CO2 extraction (SCO2) and ultrasound-assisted aqueous extraction (UAAE) were compared with the conventional solvent extraction. In comparison to solvent extraction, the oils extracted using SCO2 and UAAE were found to have higher iodine values, but lower slip melting points, free fatty acid contents and saponification values. Regardless of the extraction methods, the major fatty acids in avocado oils were oleic (40.73-42.72%) and palmitic (28.12-34.48%) acids whereas the major triacylglycerols in avocado oils were palmitoyl-dioleoyl-glycerol (POO; 22.48-23.01%) and palmitoyl-oleoyl-linoleoyl-glycerol (POL; 17.64-18.23%). SCO2 and UAAE are effective “solvent-free” methods to extract avocado oils and potentially other edible oils.

Subcritical CO2 extraction of a volatile oil-rich fraction from the seeds of Nigella sativa for potential pharmaceutical and nutraceutical applications

Seeds of black cumin (Nigella sativa L.) were subjected to subcritical CO2 extraction (SbFE) at 70 bar and 30 °C for 2 h in a trial to isolate a volatile oil-rich fraction. That treatment led to obtaining an oleoresin which constituted 1.74 wt.% of the total seeds’ weight and was found to be rich in its volatile oil content (66.6 wt.%). Traditional methods of extracting the oleoresin using n-hexane at room temperature or at 60 °C led to much higher yields (23.6 and 32.9 wt.%), respectively. The volatile oils’ content of these oleoresins was 4.75 and 3.59 wt.%. GC-MS analysis showed that the volatile oil obtained after SbFE is characterized by the highest thymoquinone (TQ) content (60.5%) compared to that obtained after hexane extraction at room temperature (37.6%) or at 60 °C (41.6%). On the other hand, TQ content of the volatile oils isolated directly from the seeds by hydrodistillation and steam distillation was much lower (10.2 and 23.7%), respectively. Based on the above mentioned, SbFE of N. sativa seeds was found to be a useful green tool for obtaining a volatile oil-rich oleoresin with high TQ percentage which can be applied in pharmaceutical and nutraceutical products.

Artemisinin content in Artemisia annua L. extracts obtained by different methods

Isolation of artemisinin from Artemisia annua L. and its quantification by the HPLC-MS method are considered. Different extraction methods were used for the isolation of artemisinin: maceration, ultrasonic and subcritical CO2-extraction. The component content of the CO2- and hexane extracts was studied by the GC-MS method.