Supercritical Fluid Carbon Dioxide Research Articles

Araçaúna (Psidium myrtoides) flour: Sequential extraction with supercritical carbon dioxide and pressurized fluids

Araçaúna (Psidium myrtoides) is a native fruit from the Brazilian Atlantic Forest. It was studied for the proximate composition of its flour and sequential extraction using supercritical fluid extraction (SFE) in the first stage with CO2 and pressurized liquid extraction (PLE) with ethanol and water in the second and third stages, respectively, at 50°C and 60°C. The proximate analysis revealed essential information about the flour regarding the content of protein, carbohydrates, lipid, ash and moisture. The sequential extraction at 60°C resulted in high yields (42.22 %). The first stage using SFE captured the volatile fraction, notably 1,4-diethylbenzene, which corresponds to 53.70 % of the total volatile compounds identified in the araçaúna. Comparing the second and third stages, the third stage with water at 50°C produced the highest levels of phenolic compounds (33.06±2.26 mg GAE/g extract), total monomeric anthocyanins (3.91±2.10 mg C3G/g extract), antioxidant activity by ORAC (415.13±13.66 µmol TE/g extract) and FRAP (747.16±18.49 µmol TE/g extract), and cyanidin-3-glucoside as the predominant compound (4.83 % w/w).

High-Quality Foaming and Weight Reduction in Microcellular-Injection-Molded Polycarbonate Using Supercritical Fluid Carbon Dioxide under Gas Counter Pressure.

Microcellular injection molding (MuCell®) using supercritical fluid (SCF) as a foaming agent to achieve weight reduction has become popular in carbon emission reduction. In the typical MuCell® process, SCF N2 is commonly used. Although SCF CO2 exhibits high solubility and can achieve a high weight reduction, controlling the foaming is not easy, and its foaming cells are usually larger and less uniform, which limits its industrial application. Our previous studies have shown that gas counter pressure (GCP) can improve the foaming quality effectively. Here, we investigated whether or not the CO2 SCF foaming quality could be improved, and weight reduction was achieved for polycarbonate (PC) material. This is quite important for the electronics industry, in which most of the housing for devices is made of PC materials. MuCell® was subjected to molding experiments using the parameters of the SCF dosage, melt temperature, mold temperature, and injection speed. The results revealed that using CO2 gas for the PC material can reduce the size of microcellular cells to 40 µm and increase the cell densities to 3.97 × 106 cells/cm3. Using GCP significantly improved the microcellular injection-molded parts by reducing the cell size to 20.9 µm (a 45.41% improvement) and increasing the cell density to 8.04 × 106 cells/cm3 (a 102.48% improvement). However, implementing GCP may slightly decrease the target weight reduction. This study reveals that microcellular injection molding of PC parts using SCF CO2 can achieve high-quality foaming and reduce the weight by about 30%.

Physicochemical Properties, Heavy Metal and Pesticide Contaminations, and Microbial Limit Tests of Cannabis Oral Drops

Cannabis, a medicinal herb renowned for its therapeutic potential, is utilized in the treatment of various ailments, including the stimulation of appetite in cancer patients. In Thailand, the predominant dosage form is oral drops; however, the absence of robust quality control measures for these products poses significant health risks to patients. The primary objectives of this study were to formulate and evaluate cannabis oral drops, with a comprehensive evaluation encompassing physicochemical properties such as appearance, pH, Δ9-tetrahydrocannabinol, and cannabidiol contents. Furthermore, heavy metals (specifically arsenic, cadmium, and lead), pesticides (including pyrethroids, organochlorines, organophosphates, and carbamates), and microbial contaminations (Staphylococcus aureus, Clostridium spp., and Salmonella spp.) were evaluated. The results revealed that the optimal formulation, comprising cannabis extract derived from supercritical carbon dioxide fluid, vitamin E acetate, and medium-chain triglyceride oil, exhibited a pH of approximately 4.0, a Δ9-tetrahydrocannabinol content of approximately 27 mg/mL, and a cannabidiol content of approximately 9 mg/mL. Furthermore, there were no heavy metals or pesticides detected. Microbial limit tests demonstrated the absence of Staphylococcus aureus, Clostridium spp., and Salmonella spp. In conclusion, this endeavor successfully achieved the development of high-quality cannabis oral drops, showcasing the potential for safe and therapeutic use.

Performance Improvement by Carbon-Dioxide Supercritical Fluid Treatment for 4H-SiC Vertical Double Diffusion MOSFETs

This study examines the impact of supercritical fluid treatment on 1200V 4H-SiC vertical double diffusion MOSFETs (VD-MOSFETs). When exposed to pure carbon dioxide or carbon dioxide mixed with nitrous oxide, there is a significant increase in the improvement ratio of drain current, which is contingent upon channel mobility but has no effect on threshold voltage. Conversely, the degradation of drain current caused by ammonia gas treatment is attributed to a reduction in channel mobility. Furthermore, the treatment with pure carbon dioxide or carbon dioxide mixed with nitrous oxide effectively passivates shallow defects, while the presence of hydrogen atoms in ammonia gas leads to an increase in shallow defects.

Prevention of supercritical carbon dioxide fluid extract from Chrysanthemum indicum Linnén on cutaneous squamous cell carcinomas progression following UV irradiation in mice.

Chrysanthemum indicum Linnén (C. indicum), a medicinal and food herb with various bioactive components, may be of beneficial use in cosmetics and the treatment of skin-related diseases. However, to date, few studies have been reported on its potential preventive and therapeutic effects on skin cancer. Therefore, the present study aimed to investigate the effect and potential mechanism of action of supercritical carbon dioxide extract from C. indicum (CISCFE) on UV-induced skin cancer in a mouse model. Kunming mice were allocated randomly to five treatment groups: Sham, model, low concentration CISCFE, high concentration CISCFE and positive control nicotinamide groups. The dorsal skin of mice was irradiated with UV light for 31 weeks. Histopathological changes, ELISA assays, immunohistochemical analysis and western blotting were performed to investigate the potential therapeutic effects of CISCFE. The results showed that CISCFE alleviated skin oxidative and inflammatory damage in a UV-induced mouse model of skin cancer. Moreover, CISCFE suppressed abnormal activation of proto-oncogene c-Myc and the overexpression of Ki-67 and VEGF, and increased expression of the anti-oncogene PTEN, thereby reducing abnormal proliferation of the epidermis and blood vessels. Additionally, CISCFE increased the protein expression levels of NAD-dependent protein deacetylase sirtuin-1 (SIRT1), Kelch-like ECH associated protein 1 (Keap1) and inhibited the expression of nuclear factor 2 erythroid 2-related factor 2 (Nrf2), phosphorylated (p)-p62 (Ser 349), p-p65 and acetyl-p65 proteins in a UV-induced skin cancer mouse model. In summary, CISCFE exhibited potent anti-skin cancer activity, which may be attributed its potential effects on the p62/Keap1-Nrf2 and SIRT1/NF-κB pathways.

Core-Shell Si@SiOC Particles Synthesized Using Supercritical Carbon Dioxide Fluid for Superior Li-Ion Storage Performance.

A supercritical carbon dioxide (SCCO2) fluid, characterized by gas-like diffusivity, near-zero surface tension, and excellent mass transfer properties, is used as a precursor to produce silicon oxycarbide (SiOC) coating. SCCO2 disperses and reacts with Si particles to form an interfacial layer consisting of Si, O, and C. After an 850°C annealing process, a conformal SiOC coating layer forms, resulting in core-shell Si@SiOC particles. High-resolution transmission electron microscopy and its X-ray line-scan spectroscopy, X-ray photoelectron spectroscopy, Fourier-transform infrared spectroscopy, and Raman spectroscopy, are used to examine the SiOC formation mechanism. Effects of SCCO2 interaction time on the SiOC properties are investigated. The SiOC layer connects the Si@SiOC particles, improving electron and Li+ transport. Cyclic voltammetry, galvanostatic intermittent titration technique, and electrochemical impedance spectroscopy are employed to examine the role of SiOC during charging/discharging. Operando X-ray diffraction data reveal that the SiOC coating reduces crystal size of the formed Li15Si4 and increases its formation/elimination reversibility during cycling. The Si@SiOC electrode shows a capacitiy of 2250 mAh g-1 at 0.2 A g-1. After 500 cycles, the capacity retention is 72% with Coulombic efficiency above 99.8%. A full cell consisting of Si@SiOC anode and LiNi0.8Co0.1Mn0.1O2 cathode is constructed, and its performance is evaluated.

The Potential Antinociceptive Effect and Mechanism of Cannabis sativa L. Extract on Paclitaxel-Induced Neuropathic Pain in Rats Uncovered by Multi-Omics Analysis.

Cannabis sativa L. (hemp) is a herbaceous plant rich in cannabinoids with a long history of use in pain treatment. The most well-characterized cannabinoids, cannabidiol (CBD) and Δ9-tetrahydrocannabinol (Δ9-THC), garnered much attention in chemotherapy-induced peripheral neuropathy (CIPN) treatment. However, few studies have investigated the biological benefits and mechanism of hemp extract on CIPN. In the present study, hemp extract (JG) rich in cannabinoids was extracted by supercritical fluid carbon dioxide extraction (SFCE). The antinociceptive efficacy was evaluated using a paclitaxel-induced peripheral neuropathy (PIPN) rat model based on behavioral tests. Further omics-based approaches were applied to explore the potential mechanisms. The results showed that JG decreased mechanical allodynia, thermal hyperalgesia, and inflammatory cytokines in PIPN rats significantly. Transcriptome analysis identified seven key genes significantly regulated by JG in PIPN model rats, mainly related to the neuroactive ligand-receptor interaction pathway, PPAR signaling pathway, and cAMP signaling pathway. In metabolomic analysis, a total of 39 significantly altered metabolites were identified, mainly correlated with pentose and glucuronate interconversions and the glycerophospholipid metabolism pathway. Gut microbiota analysis suggested that increased community Lachnoclostridium and Lachnospiraceae_UCG-006 in PIPN rats can be reversed significantly by JG. In conclusion, hemp extract exhibited antinociceptive effects on PIPN. The analgesic mechanism was probably related to the regulation of inflammation, neuroactive ligand-receptor interaction pathway, sphingolipid metabolism, etc. This study provides novel insights into the functional interactions of Cannabis sativa L. extract on PIPN.

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.

Effects of different preparation methods on the physical, chemical and functional properties of protein powders from Skipjack tuna (Katsuwonus pelamis) liver

Tuna livers (TL), which are often discarded as waste, are a valuable source of protein for human consumption. However, the preparation method used affects the nutritional and functional characteristics of protein powders. This work aimed to investigate the effects of different preparation methods on the physical, chemical, and functional properties of tuna liver protein powders (TLPPs) following heat (H) treatment, heat and ultrasound-assisted (HU) extraction, alkaline pH shift (APS) process, and supercritical carbon dioxide fluid (SC-CO2 ) extraction. H at 85°C (H85), HU at 80 kHz and 100 W (HU-80-100), APS at pH 11.5 (APS 11.5), and SC-CO2 at 350 bars (SC-CO2 -350) resulted in the remarkably highest total protein content among the different preparation conditions. All TLPPs, except for APS 11.5, showed lighter color characteristics. The most abundant amino acids in all TLPPs were glutamic acid, aspartic acid and alanine. The protein solubility and foaming capacity were efficiently improved by SC-CO2-350. Nevertheless, the emulsion properties and oil holding capacity were greatly enhanced by H85 and HU-80-100, and a significant foaming stability and water holding capacity were found in APS 11.5. Therefore, the TLPPs obtained following different preparation methods are unique and could be potentially utilized as a source of protein ingredients in several food systems.

A universal ANN-based approach predicting PCHEs’ off-design performance across various operating conditions of sCO2 RCBCs

This paper proposes a universal approach that employs artificial neural networks (ANN) to predict the off-design performance of printed circuit heat exchangers (PCHEs) using supercritical carbon dioxide (sCO2) fluid. PCHEs are widely studied precoolers and recuperators of sCO2 power cycles, for which predicting their off-design heat transfer performance is challenging due to the fluid’s dramatic non-linear property variations. Due to their narrow valid range and constrained expressing ability, the existing empirical correlations might introduce significant out-of-scope errors that result in diverged simulation results, slow convergence and abnormal quitting. This work addresses the issue by proposing an ANN-based Nusselt number correlation, ANNu, to predict the off-design performance of PCHEs quickly and universally over the vast operating range of sCO2 cycles. Multiple techniques were adopted to promote ANNu’s prediction accuracy and generalization, such as consolidating 494 training data, data-driven input selection, and global optimization for the networks’ architecture and hyperparameters. This paper comprehensively evaluates ANNu’s performance by comparing its predictions with ten empirical correlations over four typical real-world scenarios, where ANNu features an overall MSE of 83.4222 and overall MAPE of 16.285 % that rank the second best and third best among eleven candidates (even overpassing two references), respectively. Moreover, ANNu exhibits good generalization and reliability, featuring MAPEs ranging from 9.89 % to 27.73 % when processing unmet experiment data from sCO2 PCHE applications.

Solvent-Free Method for Masking the Bitter Taste of Azithromycin Dihydrate Using Supercritical Fluid Technology

ABSTRACT Introduction and purpose The unpleasant extremely bitter taste of the orally administered broad-spectrum antibiotic azithromycin decreases patient compliance, especially in pediatrics. This issue can be overcome by decreasing drug interaction with the tasting buds using insoluble polymers at salivary pH (6.8 -7.4), like the cationic polymer Eudragit EPO. Supercritical fluid technology is a green synthesis method for preparing pharmaceutical preparations that replace organic solvents with safe supercritical CO2. This study aimed to mask the bitter taste of azithromycin using the supercritical fluid method and a pH-sensitive Eudragit EPO polymer. Methods: A foaming process was investigated for preparing a formulation (TEST), which comprises treating the polymer with supercritical carbon dioxide (CO2) fluid to prepare a taste-masked dosage form without employing organic solvents or flavors. Results: The use of the supercritical technique at 40 °C and 10 MPa for two hours allowed the manufacturing of solvent-free polymeric foam with azithromycin dispersions; the average calculated percentage of apparent volume change was 62.5 ± 5.9% with an average pore diameter of 34.879 Å. The formulated sample showed low drug release in simulated salivary fluid while keeping its crystalline nature. Moreover, clinical studies on healthy subjects showed that the formula successfully masked azithromycin's bitter taste. Conclusions: Overall, it has been shown herein that the supercritical fluid technology foaming method is promising in masking the bitter taste of bitter ingredients.

Hydrophobic modification of polyvinylidene fluoride membranes in supercritical carbon dioxide fluids

Polyvinylidene fluoride (PVDF) membranes exhibit exceptional chemical stability and find applications in various fields, including building membranes, flexible sensors, blood purification, and seawater desalination. Nevertheless, the hydrophobic performance of PVDF membranes in these applications is subpar and requires enhancement. Supercritical carbon dioxide (scCO2) fluid demonstrates a beneficial expansion effect on PVDF membranes and exhibits good solubility with fluorine reagents. This study employs scCO2 as a medium to introduce a fluorine reagent onto the surface of PVDF membranes, forming a layer of low surface energy substance that significantly improves the membrane's hydrophobicity. The results indicate the feasibility of hydrophobic modification of PVDF membranes using scCO2 as a medium, leading to improved hydrophobic properties. When using a fluorine reagent with a relatively large molecular weight, PVDF membranes in scCO2 fluid at 110 °C and 20–25 MPa for 4 h results in a substantial improvement in the hydrophobicity of the PVDF membrane, with the contact angle reaching 117.2° (compared to the primitive membrane's 80°). Scanning electron microscopy (SEM) analysis confirms the presence of a layer of low surface energy material on the modified PVDF membrane surface. Thermogravimetric (TG) and differential thermogravimetric (DTG) analyses demonstrate that the hydrophobic modification using scCO2 enhances the crystallinity and thermal stability of the PVDF membrane, raising the thermal cracking temperature from 425.3 °C to 450.5 °C. Fourier-transform infrared spectroscopy (FT-IR) reveals clear absorption peaks of the fluorine reagent at 1740 cm−1 and 1211 cm−1. Nuclear magnetic resonance (NMR) confirms the presence of characteristic peaks of hydrogen on the fluorine reagent, confirming the embedding of the hydrophobic reagent onto the PVDF membrane surface. This modification method holds significant potential for guiding the development of hydrophobic surfaces, contributing to carbon neutrality, and meeting environmental sustainability goals.

Research on the Electrodeposition of Graphene Quantum Dots under Supercritical Conditions to Enhance Nickel-Based Composite Coatings

A graphene quantum dots (GQDs)-reinforced nickel-based composite coating was electrodeposited on the surface of a copper plate with a supercritical carbon dioxide fluid (SC-CO2)-assisted DC power supply. The effect of the current density on surface morphology, microstructure, average grain size, hardness, and corrosion resistance of the resulting coatings was investigated in detail. It was found that the GQDs composite coating showed a more compact surface, a smaller grain size, higher microhardness, and stronger corrosion resistance than the pure Ni coating produced in SC-CO2 and a texture coefficient indicative of a (111) preferred orientation. When the current density was 8 A/dm2, the surface morphology of the GQDs composite coating showed a high density, and the grain size was about 23 nm. In addition, the micro-hardness and corrosion resistance of the GQDs composite coating was greatly improved compared with those of the pure nickel coating; at the same time, its wear rate, friction coefficient, and self-corrosion current density were decreased by 73.2%, 17.5%, and 9.2%, respectively.

Characterization and stability evaluation of Egyptian propolis extract nano-capsules and their application

The increasing demand for natural products and biotechnological activities from bees facilitate their widespread use in food preservation and beneficial effects on humans. This study aimed to prepare and characterize the nano-capsules of Qaluiobia (PQG) governorates propolis extracted with water, ethanol and supercritical fluid-carbon dioxide at 50 °C with co-solvent. Propolis bioavailability was analyzed and introduced to prepare crackers to extend their shelf life. Nano-encapsulation was examined using transmission electron microscopy (TEM), differential scanning calorimetry (DSC) and antioxidant activity. Ethanol and supercritical fluid-carbon dioxide (SCF-CO2) at 50 °C with ethanol as co-solvent recorded higher yield, antioxidant activities, total phenolics and total flavonoids. SCF-CO2 extracts had a higher flavonoid concentration. It was revealed that propolis nano-capsules had high-temperature stability and cytotoxic effects against the three tested human cancer cell lines (i.e. PC3, MCF7 and HePG2). The higher overall acceptability of crackers fortified with PQG was achieved with SCF-CO2 at 50 °C and ethanol extract nano-capsules, i.e. 86.57% and 86.29% respectively. The higher ability to retain antioxidant activity reduces the increase of peroxide value (PV), preventing rancidity and increasing the shelf life of crackers during the storage period. Practical application: This study can provide a suitable method for extracting bioactive compounds from propolis, and improve the biological properties and activities by nano-encapsulation, also reveals the extent of its use as a natural antioxidant and anticancer and its application in bakery products as a functional food.

Supercritical extraction technique of agarwood essential oil induced by plant hormones

Samples of agilawood (agarwood), which were studied in this work, were produced in Zhongshan City, Guangdong Province, China. To enhance incense production, a specific concentration of plant hormone is employed for induction. The extraction technology of agilawood essential oil was explored using supercritical carbon dioxide fluid, which exhibited a more pronounced induction effect. The pressure, temperature, and flow rate, respectively, were 8, 16, and 24 MPa; 35, 45, and 55 °C; and 20, 30, and 40 L/h. A Box-Behnken analysis was adopted for experimental data, which involved 33 experiments. The data were fitted with the equation Y = 2.18 + 0.1312X1 – 0.025X2 + 0.1236X3 – 0.0025X1X2 – 0.0125X2X3 + 0.0175X12 + 0.035X22 – 0.1275X32. Hence, the optimal process parameters in the supercritical extraction of agarwood essential oil were as follows: the pressure, temperature, and flow rate of 24 MPa, 35 °C, and 33 L/h, respectively. An analysis was conducted with the statistical analysis software Design-Expert 11, which indicated that the extraction yield of agarwood essential oil by supercritical carbon dioxide was mainly affected by the pressure and flow rate. The yield was proportional to the pressure and flow, and inversely proportional to the temperature.

Evaluation of control of additive concentration in gradient analysis of supercritical fluid chromatography-coupled to tandem mass spectrometry

Mobile phase additives are used to improve retention behavior in chromatography. In supercritical fluid chromatography (SFC), for which supercritical fluid carbon dioxide (SF-CO2) is used as the main mobile phase, additives can only be added into the modifier. For that reason, when gradient analysis is performed by changing the modifier ratio to SF-CO2, the additive concentration in the mobile phase increases in parallel with the modifier ratio. In a preliminary study performed using the conventional SFC system, ammonium acetate was necessary to improve the peak shape of a polar steroid, dehydroepiandrosterone sulfate (DHEA-S), while the peak intensity of a non-polar steroid, progesterone, decreased by 78% compared to that in the absence of the additive in mobile phase when gradient elution was performed. Since ammonium acetate had both favorable and unfavorable effects on sensitive and simultaneous analysis of these two steroid compounds, a compromise between these effects had to be sought. A three-pump configuration of SFC was developed by adding a pump unit to SFC instrument, which enabled control of the additive concentration independently of the modifier ratio, for the purpose of investigating the additive effect in detail using both steroids as model compounds. The putative cause of the decrease in peak intensity of progesterone was excessively elevated additive concentration in gradient analysis. When the additive concentration in the mobile phase was controlled to ensure that it did not increase during gradient analysis, the peak intensities of progesterone, cortisol, corticosterone, and testosterone were 55%, 40%, 25%, and 17% higher than when the additive concentration was not controlled, respectively. On the other hand, the peak intensity of DHEA-S was almost identical between the conditions, with an increase of 2% with three-pump instrument. The three-pump configuration showed the potential to solve problems relating to the use of modifier additives by keeping their concentration constant in gradient SFC analysis.

Optimization of Supercritical Carbon Dioxide Fluid Extraction of Medicinal Cannabis from Quebec

Research on cannabis oil has evolved to encompass the pharmaceutical industry for the therapeutic potential of the active compounds for pathologies such as Alzheimer, auto-immune disorders, and cancer. These debilitating diseases are best treated with cannabinoids such as tetrahydrocannabinol (∆9-THC), cannabigerol (CBG), and cannabinol (CBN), which relieve neuropathic pain and stimulate the immune system. We extracted cannabinoids from plants with supercritical CO2 and produced an extract with a total yield close to 26%. The three-level Box–Behnken experimental design considered four factors: Temperature, pressure, CO2 flow rate, and processing time, with predetermined parameters at low, medium, and high levels. The mathematical model was evaluated by regression analysis. The yield of ∆9-THC and CBG reached a maximum after 2 h and 15 g/min of CO2, 235 bar, 55 °C (64.3 g THC/100 g of raw material and 4.6 g CBG/100 g of raw material). After another 2 h of extraction time, the yield of CBN reached 2.4 g/100 g. The regression analysis identified pressure and time as the only significant factors for total yield while pressure was the only significant factor for ∆9-THC and CBG. Time, temperature, pressure, and flow rate were all significant factors for CBN.

Optimization of Supercritical Fluid CO2 Extraction from Yellow Horn Seed and Its Anti-Fatigue and Antioxidant Activity.

A supercritical fluid carbon dioxide (SF-CO2) extraction method was used to obtain the optimum process for extracting yellow horn seed oil. The anti-fatigue and antioxidant properties of the extracted oil were investigated through animal experiments. The optimum process conditions for SF-CO2 extraction of the yellow horn oil were 40 MPa, 50 °C and 120 min, with an extraction yield of 31.61%. The high-dose group of yellow horn oil could significantly increase the weight-bearing swimming time, the hepatic glycogen (HG) content and decrease the lactic acid (LA) content and blood urea nitrogen (BUN) content (p < 0.05) in mice. Moreover, it improved the antioxidant ability by reducing the malondialdehyde (MDA) content (p < 0.01) and raising the glutathione reductase (GR) content and superoxide dismutase (SOD) content (p < 0.05) in mice. Yellow horn oil has the effects of being an anti-fatigue and antioxidant substance, which provides a basis for its further utilization and development.

Evolution of Supercritical Fluid Carbon Dioxide Dyeing Technology: Comparison of Predictive and Experimental Affinity and Dyeability between PET Fiber and Various Disperse Dyes

Evolution of Supercritical Fluid Carbon Dioxide Dyeing Technology: Comparison of Predictive and Experimental Affinity and Dyeability between PET Fiber and Various Disperse Dyes

Evaluation of carbon dioxide supercritical fluid extraction (CO2-SFE) on carotenoids recovery from red yeast cells

AbstractIn this work, the performance of carotenoids extraction from Rhodotorula spp red yeast (strain ELP2022) using supercritical CO2 (CO2-SFE) was compared to the traditional technique with organic solvent. For this purpose, the yeast was cultured in liquid medium, pre-treated with glass beads in 0.1 M NaHCO3, and lyophilized. The extraction by CO2-SFE was carried out using a bench scale equipment at 300, 400, and 500 bar whilst maintaining a constant CO2 flow rate (6 mL/min) and temperature (40 °C) resulting in an average extraction yields of 60.8 ± 1.1, 68.0 ± 1.4, and 67.6 ± 1.4 µg of total carotenoids per g of yeast (dry weight), respectively. Based on these results, three other experiments at 400 bar and a CO2 flow rate of 6 L/min were also performed. In specific, the temperature was increased up to 60 °C, and ethanol as a co-solvent was added at 40 and 60 °C. The results showed that the temperature does not have a significant effect on the extraction of carotenoids. On the contrary, the yields improved significantly in the presence of the co-solvent, and the percentage of recovery reached the mean values of 71.70% ± 1.4 and 73.86% ± 1.9 at 40 and 60 °C, respectively. Furthermore, from chromatographic analysis, four major peaks were observed and identified as torularhodin, torulene, γ-carotene, and β-carotene which represented about 53.4%, 6.4%, 8.3%, and 26.9% of total carotenoids, respectively. Therefore, these promising results show the potential of this green technique for obtaining high-value products, such as carotenoids, from yeasts and therefore avoiding the use of dangerous solvents.