Comparison of essential oil compositions of Salvia mirzayanii obtained by supercritical carbon dioxide extraction and hydrodistillation methods

Essential oil of Salvia mirzayanii cultivated in Iran was obtained by hydrodistillation and supercritical (carbon dioxide) extraction methods. The oil was analysed by capillary gas chromatography using flame ionization and mass spectrometric detections. The compounds were identified according to their retention indices and mass spectra (EI, 70 eV). The effects of different parameters such as pressure, temperature, modifier volume and extraction times (dynamic and static) on the supercritical fluid extraction (SFE) of S. mirzayanii oil were investigated. The results showed that, under a pressure of 35.5 MPa, temperature of 35 °C, 6% methanol, dynamic extraction time of 50 min and static extraction time of 30 min, extraction was more selective for the linalyl acetate. Thirty four compounds were identified in the hydrodistilled oil. The major components of S. mirzayanii were linalyl acetate (7.6%), 1,8-cineole (8.0%), linalool (9.0%) and 8-acetoxy linalool (11.0%). However, by using supercritical carbon dioxide in optimum conditions, only three components contain more than 63% of the oil. The yield of the obtained oil based on hydrodistillation was 2.20% (v/w). Extraction yield based on the SFE varied in the range of 1.50–9.67% (w/w) under different conditions. The results revealed that, in Iranian S. mirzayanii oil, linalyl acetate is a major component.     

Application of response surface methodology and central composite design for the optimisation of supercritical fluid extraction of essential oils from Myrtus communis L. leaves

Essential oils of Myrtus communis L. leaves were obtained using supercritical fluid extraction (SFE) and hydrodistillation methods. The experimental parameters of SFE such as pressure, temperature, modifier volume, static and dynamic extraction time were optimised using a central composite design after a 2ⁿ⁻¹ fractional factorial design. The chemical compositions of the SFE extract were identified by GC–MS and determined by GC–FID. The major components of essential oils obtained by hydrodistillation were α-pinene (31.8%), 1,8-cineole (24.6%), limonene (14.8%), linalool (8.3%) and α-terpinolene (4.8%). However, by using the supercritical carbon dioxide in optimum conditions, only three components represented more than 85% of the extract. Therefore, by using the proper SFE conditions, the supercritical extraction is more selective than the conventional hydrodistillation methods. The oil yields based on the hydrodistillation was 0.47% (v/w). Extraction yields based on the SFE varied in the range of 0.5–6.3% (w/w) under different conditions.     

Supercritical fluid extraction of daidzein and genistein isoflavones from soybean hypocotyl after hydrolysis with endogenous β-glucosidases

An optimal condition of supercritical fluid extraction (SFE) for isoflavone aglycones (daidzein and genistein) in soybean hypocotyls previously subjected to thermohydration at pH 5.0 and a temperature of 50 °C for 6, 12 and 18 h was developed. Different temperatures, pressures and cosolvents (methanol, ethanol, and acetonitrile) was tested and compared with solid–liquid extraction using aqueous methanol solution (80% v v⁻¹) conducted in parallel for comparison. The extraction conditions were 50–70 °C, 176–380 bar, adding 0, 5, 10 mol% of cosolvents 80% in water as a modifier. The results from SC–CO₂ showed that the cosolvent and pressure have significant effects in the extraction efficiency. It was found that the extraction conditions promoting the highest extraction of daidzein and genistein were at the temperature of 60 °C, pressure of 380 bar and both static and dynamic extraction of 15 min with the addition of 10% acetonitrile (80% v v⁻¹). The maximum amounts of daidzein and genistein extracted by each method were solid–liquid extraction (70.07 mg 100 g⁻¹) and carbon dioxide–acetonitrile (17.97 mg 100 g⁻¹). The yield of daidzein and genistein achieved by a 30 min SC–CO₂ extraction on soybean hypocotyls after 12 h soaking time was markedly improved by the addition of a modifier (acetonitrile) to the CO₂ fluid. HPLC analysis of the obtained extracts revealed that extraction of isoflavone aglycones by SC–CO₂ was 4.78 and 13.19 mg 100 g⁻¹ for daidzein and genistein, respectively. The contents of daidzein and genistein obtained in the solid–liquid extraction were superior to 86% and 63%, respectively, compared to supercritical extraction.     

Supercritical carbon dioxide fluid extraction of Hibiscus cannabinus L. seed oil: A potential solvent-free and high antioxidative edible oil

The supercritical fluid extraction (SFE) trends and antioxidant activities of Hibiscus cannabinus seed oils were studied. SFE results indicate that extraction pressure is the major factor determining the oil yield. In comparison, classic Soxhlet extraction (SOX/L) yielded higher oil content than SFE (P < 0.05). However, no significant differences in oil content were observed in SFE at 600 bars/80 °C, rapid Soxhlet extraction (SOX/S) and conventional ultra-sonic assisted solvent extraction (SONIC) (P > 0.05). Antioxidant activities of H. cannabinus seed oils were compared with 7 types of commercial edible oils. DPPH scavenging activity test indicated that H. cannabinus seed oil extracted by SFE at 200 bars/80 °C possessed the highest antiradical activity whereas beta-carotene bleaching (BCB) assay revealed that all H. cannabinus seed oils (except for SFE at 400 bars/80 °C and 600 bars/80 °C) exhibited higher antioxidant activity than all commercial edible oils (P < 0.05). Thus, SFE – H. cannabinus seed oil may serve as an excellent source of solvent-free edible oil with high antioxidant properties.     

Supercritical fluid extraction of Coriandrum sativum and subsequent separation of isocoumarins by high-speed counter-current chromatography

A novel supercritical fluid extraction (SFE) method has been developed for extracting essential oil from the aerial part of Coriandrum sativum. Various experimental conditions were investigated to optimise the SFE. It suggested that the extraction of 35 °C, 8 MPa, 2 h might be the optimisation to get the maximum of coriander essential oil. Then, high-speed counter-current chromatography (HSCCC) was successfully used in one step for the isolation and purification of coriandrone B, coriandrin, dihydrocoriandrin and coriandrone A from the coriander oil with a two-phase system composed of n-hexane–ethyl acetate–methanol–water (3:7:5:5, v/v/v/v) for the first time. High-performance liquid chromatography (HPLC) was employed to analyse the HSCCC fractions and revealed that the purities of the isocoumarins were all above 90%, and the chemical structures were identified by spectroscopic analysis including ESIMS, ¹H NMR and UV.     

Supercritical fluid extraction in situ derivatization for simultaneous determination of chloramphenicol,florfenicol and thiamphenicol in shrimp

The applicability of supercritical fluid extraction in situ derivatization was investigated for determination of trace amounts of amphenicols (chloramphenicol, florfenicol and thiamphenicol) in shrimp. Quantification was performed by using electron-capture negative chemical ionisation-gas chromatography/mass spectrometry (NCI–GC/MS). The parameters of supercritical fluid extraction (addition of modifier, temperature, pressure, extraction time and extraction mode) and in situ derivatization (collection solvent and derivatization reagent) were varied with control. The optimum extractions were obtained using 600 μL ethyl acetate as a modifier for supercritical carbon dioxide with static extraction for 5 min, then dynamic extraction for 10 min at 25 MPa and 60 °C. The conditions for in situ derivatization were 200 μL N,O-bis(trimethylsilyl) trifluoroacetamide containing 1% trimethylchlorosilane in 20 mL ethyl acetate as collection solvent. The new method of supercritical fluid extraction in situ derivatization was found to be linear over the concentration range of 20–5000 pg/g, with detection limits ranging from 8.7 to 17.4 pg/g (using the selective ion monitoring mode), with a R.S.D. (relative standard deviation) less than 15.3% (n = 5). Analysis of spiked shrimp samples revealed that matrix had little effect on extraction. The results presented here indicate that supercritical fluid extraction in situ derivatization is for the trace analysis of amphenicol bacteriostats in shrimp samples.     

Analysis of ginsenosides in Panax ginseng in high pressure microwave-assisted extraction

High pressure microwave assisted extraction (HPMAE) was applied to extract the ginsenosides from Panax ginseng root. The influences of extraction solvent, extraction pressure and extraction time were individually investigated. HPMAE has been compared with other extraction methods, including Soxhlet extraction, ultrasound-assisted extraction and heat reflux extraction. The determination of ginsenosides was performed by HPLC–ESI-MS. The results indicated that the HPMAE not only took a shorter time but also afforded higher extraction yields of ginsenosides, especially ginsenoside Rb₁, Rc, Rb₂ and Rd. Furthermore, the neutral ginsenosides and malonyl ginsenosides in Panax ginseng root extracts by HPMAE were investigated. The malonyl ginsenoside m-Rb₁, m-Rc, m-Rb₂ and m-Rd degraded in HPMAE at 400 kPa (109–112 °C) in 70% (v/v) ethanol–water and at 600 kPa (112–115 °C) in methanol, and transformed into corresponding neutral ginsenoside Rb₁, Rc, Rb₂ and Rd. Using water as extraction solution, the neutral ginsenosides degraded under HPMAE at 400 kPa (135–140 °C), and transformed into less polarity rare ginsenosides.     

Emulsifying and foaming properties of Phaseolus vulgaris and coccineus proteins

Protein isolates from two Phaseolus cultivars, common bean (Phaseolus vulgaris L.) and scarlet runner bean (Phaseolus coccineus L.), were prepared by wet extraction methods (isoelectric precipitation – 4000 rpm, ultrafiltration, extraction with NaCl 2%, and isoelectric precipitation – 9900 rpm). The protein isolates were characterized by sodium dodecyl sulfate–polyacrylamide gel electrophoresis and then evaluated for their solubility. The emulsion stability of emulsions produced at pH 7.0 and 5.5 with 1% or 2% or 3% w/v protein isolate was evaluated by average droplet size diameter, viscosity and creaming measurements. Emulsions with 1% protein content were unstable through storage. Emulsions with 3% w/v protein isolate concentration, extracted by ultrafiltration at pH 5.5 from both cultivars, were flocculated; this was more pronounced for coccineus isolates. The foaming properties, for the respective foams, were investigated. Foams with 1% w/v protein showed little foaming ability Ultrafiltration isolates produced more foam, which was especially stable at pH 5.5.     

Comparison of essential oil composition of Carum copticum obtained by supercritical carbon dioxide extraction and hydrodistillation methods

Essential oil of Carum copticum cultivated in Iran was obtained by hydrodistillation and supercritical (CO₂) extraction (SFE) methods. The oils were analysed by capillary gas chromatography, using flame ionization and mass spectrometric detection. The compounds were identified according to their retention indices and mass spectra (EI, 70 eV). The effects of different parameters, such as pressure, temperature, modifier volume and extraction time, on the supercritical fluid extraction of C. copticum oil were investigated. The results showed that, under pressure of 30.4 MPa, temperature 35 °C, methanol 0% and dynamic extraction time of 30 min, the method was most selective for the extraction of thymol. Eight compounds were identified in the hydrodistilled oil. The major components of C. copticum were thymol (49.0%), γ-terpinene (30.8%), p-cymene (15.7), β-pinene (2.1%), myrcene (0.8%) and limonene (0.7%). However, by using supercritical carbon dioxide under optimum conditions, only three components constituted more than 99% of the oil. The extraction yield, based on hydrodistillation was 2.8% (v/w). Extraction yield based on the SFE varied in the range of 1.0–5.8% (w/w) under different conditions. The results show that, in Iranian C. copticum oil, thymol is a major component.     

Supercritical fluid extraction and hydrodistillation for the recovery of bioactive compounds from Lavandula viridis L’Hér

The chemical profiles of bioactive essential oil and extracts obtained by hydrodistillation (HD) and supercritical fluid extraction (SFE), respectively, from Lavandula viridis were compared. The SFE was performed at 40 °C and at extraction pressures of 12 or 18 MPa in two different separators. Evaluation of the essential oil and SFE extracts by GC–FID and GC–IT–MS revealed that oxygen-containing monoterpenes were the major constituents in both cases, but there were important differences between the chemical profiles produced by the different extraction techniques. More compounds were isolated by HD but higher yields were achieved by SFE. Camphor was the main component identified in the essential oil (31.59 ± 1.32%), and in extracts from the first (1.61 ± 0.34%) and second SFE separators (22.48 ± 1.49%) at 12 MPa. In contrast, the first separator SFE extract at 18 MPa (heavy compounds) was dominated by myrtenol (5.38 ± 2.04%) and camphor (4.81 ± 1.93%), whereas the second separator SFE extract (volatiles) was dominated by verbenone (13.97 ± 5.27%). The essential oil and heavy compound extracts from the first separator possessed antioxidant and anti-cholinesterase activities. Our data show that phytochemicals from the aerial parts of L. viridis could be developed as natural antioxidant and anti-cholinesterase drugs, with particular applications in the symptomatic treatment of Alzheimer’s disease.     

Effects of binary solvent extraction system,extraction time and extraction temperature on phenolic antioxidants and antioxidant capacity from mengkudu (Morinda citrifolia)

An investigation into the effects of ethanol concentration (0–100%, v/v), extraction time (20–120 min) and extraction temperature (25–65 °C) on the extraction of phenolic antioxidants from mengkudu (Morinda citrifolia) was performed using a single-factor experiment. Total phenolic content (TPC) and total flavonoid content (TFC) assays were used for determination of phenolic compounds. Antioxidant capacity was evaluated by measuring the scavenging effect on 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) and 2,2′-diphenyl-1-picrylhydrazyl (DPPH) radicals. Experimental results showed that extraction conditions had significant effect on extraction of phenolic compounds and antioxidant capacities. The optimised conditions were 40% ethanol for 80 min at 65 °C, with values of 919.95 mg GAE/100 g DW for TPC, 472.73 mg CE/100 g DW for TFC, 791.71 μmol TEAC/100 g DW for ABTS and 1928.5 μmol TEAC/100 g DW for DPPH. TPC was significantly correlated with DPPH under the effects of ethanol concentration (r = 0.932) and extraction time (r = −0.938).     

Response surface optimised extraction and chromatographic purification of rosmarinic acid from Melissa officinalis leaves

The extraction of lemon balm (Melissa officinalis) leaves with aqueous methanol was optimised using response surface methodology. Fifteen runs were conducted following a Box-Behnken design (BBD) followed by ridge analysis using the concentration of methanol, the extraction temperature and time as the independent variables and taking the extraction yield of RA from lemon balm as the response variable. The optimal extraction conditions were a methanol concentration of 59.0% (v/v), a temperature of 54.8 °C and a time of 64.8 min, which gave a maximal RA yield of 46.1 mg RA/g dry materials. The RA extract was loaded onto a column packed with Sephadex LH-20 and then was eluted with 100% methanol, which resulted in RA with a purity of 38.8% and a yield of 43.8%. The purity of RA increased by 3.1-fold when compared to its initial purity in the extract obtained from extraction.     

Selective extraction,structural characterisation and antifungal activity assessment of napins from an industrial rapeseed meal

This article reports an extraction–purification of napins from an industrial rapeseed meal and the assessment of their antimicrobial activity against Fusarium langsethiae. The best extraction conditions are observed at pH 2, 12% (w/w) of rapeseed meal after 15 min of extraction in water at room temperature. Under these conditions the extraction is highly selective, allowing a simple purification process (ammonium sulfate precipitation followed by desalting size exclusion chromatography) to get purified napins. These napins possessed significant anti-Fusarium activity (IC₅₀ = 70 μM) and a compact secondary structure rich in α-helix, which may explain this bioactivity.     

Central composite design for the optimization of supercritical carbon dioxide fluid extraction of fatty acids from Borago officinalis L. flower

Abstract: In the present study, fatty acids and essential oils of the flower of borage (Borago officinalis L.) were obtained by supercritical carbon dioxide fluid extraction under different conditions. The extracts obtained were compared to oils of borage flower oil isolated by hydrodistillation. The obtained oils were analyzed by gas chromatography mass spectrometry. The compounds were identified according to their retention indices and mass spectra. The experimental parameters of supercritical fluid extraction (SFE) were optimized using a central composite design after a full factorial experimental design. Extraction yields based on SFE varied in the range of 0.02% to 1.96% (w/w), and the oil yield based on the hydrodistillation was 0.05% (v/w). The optimum conditions of SFE were obtained at a pressure of 350 atm, a temperature of 65 °C, a methanol modifier volume of 100 μL, and static and dynamic extraction time of 10 min. Main components of the extracts under optimum SFE conditions were palmitic acid, linoleic acid, γ‐linolenic acid, and oleic acid. The results indicated that by using the suitable extraction conditions, SFE is more effective than the conventional hydrodistillation method in the extraction of fatty acids and the preservation of its quality. Practical Application: SFE is a good technique for the extraction of oils from plants. The extraction yields by SFE are more than the conventional method. SFE is used on a large scale for production of essential oils and pharmaceutical products from plants.     

Application of a UV–vis detection-HPLC method for a rapid determination of lycopene and β-carotene in vegetables

The purpose of this paper is to optimize an HPLC method for the determination of lycopene and β-carotene in vegetables and compare it with a spectrophotometric standard method. Among the different conditions studied the most suitable ones for our samples were: extraction with hexane/acetone/ethanol (50:25:25 v/v/v), evaporation of the hexane layer, dissolution of the dry extract in THF/ACN/methanol (15:30:55 v/v/v) and injection on a C18 column with methanol/ACN (90:10 v/v) + TEA 9 μM as mobile phase (Φ = 0.9 ml/min) and λ_detection = 475 nm. Samples considered for analysis were: tomato, carrot, pepper, watermelon, persimmon and medlar. The HPLC method proposed showed adequate reproducibility (RSD < 10.5%), accuracy (100–109% recovery) and sensitive detection limits (0.6 μM for lycopene; 0.3 μM for β-carotene), with a simple preparation of the samples (one step direct extraction) and short run times (10 min) for the quantification of lycopene and β-carotene.     

Supercritical fluid extraction of forskolin from Coleus forskohlii roots

Forskolin (FSK), a labdane diterpene compound having high nutraceutical and therapeutic activity has been extracted from dried Coleus forskohlii roots using supercritical carbon dioxide (SC-CO₂). The solubility parameter of FSK, CO₂, and entrainer solvents was calculated and validated with experimental results. Theoretically, pressure and temperature had significant effect on extraction of FSK. A maximum of 50.32% recovery of FSK was obtained after SC-CO₂ extraction at 40 °C, 250 bar and extraction time of 60 min. Use of methanol as an entrainer at 20% v/w of dried C. forskohlii roots under optimized conditions improved the recovery of FSK to 74.29%. The recovery of FSK further increased marginally to 77.08% when pre-treated with ultrasonication and commercial enzyme preparation of Stargen® 002 and Accellerase® 1500.     

Pressurised liquid extraction combining LC–DAD–ESI/MS analysis as an alternative method to extract three major flavones in Citrus reticulata ‘Chachi’ (Guangchenpi)

Pressurised liquid extraction (PLE) of three major flavones (hesperidin, nobiletin, and tangeretin) from the peels of Citrus reticulata ‘Chachi’ (Guangchenpi) was investigated. These flavones were quantified and analysed by liquid chromatography–diode array detector–electrospray ionisation mass spectrometry (LC–DAD–ESI/MS). The PLE procedure was optimised, validated and compared with other conventional extraction techniques. PLE gained the best result due to the highest extraction efficiency within the shortest extraction time. The optimal conditions of PLE were employing 70% methanol as extraction solvent at a temperature of 160 °C and extraction pressure of 1500 psi, using one extraction cycle with a static extraction time of 20 min. MS coupling with an ESI interface in the positive ion mode was used as the detection technique. This is the first report on combining PLE with LC–DAD–ESI/MS for the extraction and quantification of flavones in Citrus reticulata ‘Chachi’.     

Response surface optimisation for the extraction of phenolic compounds and antioxidant capacities of underutilised Mangifera pajang Kosterm. peels

The optimum extraction conditions for highest recovery of total phenolics content (TPC) and antioxidant capacities (AC) were analysed for Mangifera pajang peels (MPP), using response surface methodology. The effects of ethanol concentration (X₁: 20–80%), extraction temperature (X₂: 30–65 °C) and liquid-to-solid ratio (X₃: 20–50 mL/g) on the recovery of total phenolics (Y₁) and antioxidant capacity (Y₂) were investigated. A second order polynomial model produced a satisfactory fitting of the experimental data with regard to total phenolic content (R² = 0.9966, p < 0.0001) and antioxidant capacity (R² = 0.9953, p < 0.0001). The optimum extraction conditions for TPC were 68%, 55 °C and 32.7 mL/g, and for AC were 68%, 56 °C and 31.8 mL/g, respectively. Predicted values for extraction of TPC and AC agreed well with the experimental values. Liquid chromatography–mass spectrometry of the optimally obtained extracts from MPP revealed the major phytochemicals as mangiferin, gallic acid, catechin and epicatechin.     

Isolation of hesperidin from peels of thinned Citrus unshiu fruits by microwave-assisted extraction

Simultaneous extraction by microwave-irradiation and crystallisation were performed in the same pot of solvent of 70% (v/v) aqueous ethanol for isolation of hesperidin from thinned immature fruit peels of Citrus unshiu as refining of Citrus waste biomass. The hesperidin content in immature fruits peels was about 3.2-fold higher than that of mature fruit. After microwave-assisted extraction (MAE), the yield of hesperidin reached 58.6 mg/g, which was comparable to the amount obtained after extraction using DMSO:methanol (1:1, v/v) as a solvent for 30 min at room temperature. Heating temperature and time for isolation of hesperidin crystallites were optimised as 140 °C and 8 min by using response surface methodology. Under this optimal condition, 86.8% (47.7 mg/g) of total hesperidin was isolable by MAE and low-temperature storage (5 °C, 24 h).     

Supercritical carbon dioxide extraction of polyunsaturated fatty acids from Northern shrimp (Pandalus borealis Kreyer) processing by-products

This study investigated the potential of Northern shrimp (Pandelus borealis Kreyer) by-products as a source of omega-3 polyunsaturated fatty acids (ω-3 PUFAs). The by-products (heads, shell and tail) of processing accounted for approximately 50–60% of the catch. Supercritical CO₂ extraction (SFE) of the by-products at 35 MPa and 40 °C generated a deep red oil, rich in ω-3 PUFAs, specifically 7.8 ± 0.06% eicosapentaenoic acid (EPA) and 8.0 ± 0.07 % docosahexaenoic acid (DHA).