Effect Of Supercritical Carbon Dioxide Research Articles

Development of Delivery Systems with Prebiotic and Neuroprotective Potential of Industrial-Grade Cannabis sativa L.

This study delves into the transformative effects of supercritical carbon dioxide (scCO2) cannabis extracts and prebiotic substances (dextran, inulin, trehalose) on gut bacteria, coupled with a focus on neuroprotection. Extracts derived from the Białobrzeska variety of Cannabis sativa, utilising supercritical fluid extraction (SFE), resulted in notable cannabinoid concentrations (cannabidiol (CBD): 6.675 ± 0.166; tetrahydrocannabinol (THC): 0.180 ± 0.006; cannabigerol (CBG): 0.434 ± 0.014; cannabichromene (CBC): 0.490 ± 0.017; cannabinol (CBN): 1.696 ± 0.047 mg/gD). The assessment encompassed antioxidant activity via four in vitro assays and neuroprotective effects against acetylcholinesterase (AChE) and butyrylcholinesterase (BChE). The extract boasting the highest cannabinoid content exhibited remarkable antioxidant potential and significant inhibitory activity against both enzymes. Further investigation into prebiotic deliveries revealed their proficiency in fostering the growth of beneficial gut bacteria while maintaining antioxidant and neuroprotective functionalities. This study sheds light on the active compounds present in the Białobrzeska variety, showcasing their therapeutic potential within prebiotic systems. Notably, the antioxidant, neuroprotective, and prebiotic properties observed underscore the promising therapeutic applications of these extracts. The results offer valuable insights for potential interventions in antioxidant, neuroprotective, and prebiotic domains. In addition, subsequent analyses of cannabinoid concentrations post-cultivation revealed nuanced changes, emphasising the need for further exploration into the dynamic interactions between cannabinoids and the gut microbiota.

Effect of supercritical carbon dioxide on protein structure modification and antimicrobial peptides production of Mongolian cheese and its in vitro digestion

The aim of this research was to investigate the effects of supercritical carbon dioxide (SC-CO2) treatment on protein structure in Mongolian cheese. The peptides during the digestive process of the SC-CO2 treated cheese were also studied. SC-CO2 technology was utilized to treat Mongolian cheese at three temperatures (45, 55 and 65 °C) and three pressures (7.5, 12.5 and 17.5 MPa). The results of fluorescence, ultraviolet–visible, Fourier transform infrared spectroscopy and free sulfhydryl groups showed that SC-CO2, particularly at 65 °C and 17.5 MPa, modified the protein structure in Mongolian cheese effectively. The data of LC-MS/MS-based peptidomics showed that the content of antimicrobial peptides found in the SC-CO2 treated Mongolian cheese was 1.55 times that of the untreated Mongolian cheese; the content of unique antimicrobial peptides in the digested SC-CO2 treated Mongolian cheese was 1.46 times that of the digested untreated Mongolian cheese, which proved that SC-CO2 could help produce antimicrobial peptides in cheese not only during the process of SC-CO2 treatment but during subsequent simulated gastrointestinal digestion as well. In conclusion, SC-CO2 could be considered a promising method to develop cheese products with potential health benefits.

Effect of supercritical carbon dioxide on pore structure and methane adsorption of shale with different particle sizes

Supercritical carbon dioxide (SCCO2) fracturing significantly enhances shale gas recovery, which is influenced by particle size. We soaked shale in SCCO2 and investigated the impact of SCCO2 on different particle sizes. Large-particle shales showed the largest percentage changes in specific surface area and total pore volume (54.11 %, 87.87 %; 58.59 %, 76.32 %) followed by small-particle size shales. This trend was also observed in other pore structure parameters. The particle-size effect is: Large-particle shale, with abundant microfractures, enhances SCCO2 flow and pore alteration. Small-particle shale's high specific surface area facilitates SCCO2 penetration. Medium-particle shale is less affected due to balanced interactions of these factors. Methane is primarily found in large and medium pores and microfractures. Methane adsorption in shale mainly involves multi-layer adsorption. Following SCCO2 treatment, pore fractures narrowed, increasing the proportion of methane molecules adsorbed as a single-layer. This study is crucial for evaluating the fracturing effects on shale gas wells.

Carbonation strengthening mechanism of dry cement-based materials under supercritical carbon dioxide

Long-term stability of concrete as a wellbore sealing material is enhanced by the interaction between Portland cement and supercritical carbon dioxide. This study is to explore the mechanism of the strengthening effect of supercritical carbon dioxide on cement-based materials. After supercritical carbonation curing, the compressive strength of dry samples is increased by 93 %∼123 %. By using regional characterization analysis, the relationship between chemical reaction process and local mechanical property changes is established. The supercritical carbonation process and reaction kinetics are uncovered. On the one hand, the carbonation products form a compacted layer in the external area of cement paste, with a local microhardness increase of 30 % for 7d and 102 % for 28d, playing hoop effect on strengthening; On the other hand, the inward aggregation of carbonation produced water promotes the local “rehydration”, increasing the degree of hydration by 3.89 %∼15.98 %, which benefits strength development. The transport and accumulation of the produced water are the main limiting factors which obstruct the continuous penetration of supercritical carbonation.

Enzymic Deactivation in Tender Coconut Water by Supercritical Carbon Dioxide

Polyphenol oxidase (PPO) and peroxidase (POD) are target enzymes in the processing of tender coconut water (TCW). This study primarily evaluated the combined effect of supercritical carbon dioxide (SC-CO2) and mild temperatures on the PPO and POD deactivation of TCW. A factorial design was performed to investigate the effect of temperature (in the range of 35 to 85 °C), pressure (75 to 370 bar), and holding time (13 to 47 min) on the enzymic deactivation, physicochemical parameters, and color of the TCW. The percentages of reduction in PPO activity ranged from 3.7 to 100%, and POD ranged from 43.4 to 100%. The pH values of the freshly extracted and processed TCW were 5.09 and 4.90, and the soluble solids content were 5.5 and 5.4 °Brix, respectively. The holding time (t) had a significant effect (p ≤ 0.1) on the total color variation. As for the reduction of PPO activity, the temperature (T) and the interaction between pressure (P) and t had a significant effect. None of variables (P, T, or t) affected (p > 0.1) the POD reduction, pH, and soluble solids variation. The combination of SC-CO2 and mild temperatures is a promising intervention in the enzymic stabilization of TCW.

Quality properties and nutritional compounds of fresh-cut pumpkin treated with supercritical carbon dioxide

The work aimed to explore the effect of supercritical carbon dioxide (SCCD) treatment on the enzyme activity, color, carotenoid, sugar and phenolic profile, and antioxidant activity of fresh-cut pumpkins. The polyphenol oxidase (PPO) and peroxidase (POD) activities of SCCD-treated pumpkin cubes were reduced by 21% and 18%, respectively. The lightness value of SCCD-treated samples declined compared to the untreated samples, whereas the redness and yellowness values in treated samples were enhanced. The lutein, α-carotene, β-carotene and total carotenoids, glucose, sorbitol, and other polysaccharides in the SCCD-treated samples showed a fluctuation trend. Similarly, the treated sample's total phenolic contents (TPC), ABTS (2,2′- azino-bis(3-ethylbenzothiazoline-6-sulfonic acid, DPPH (2,2-diphenyl-1-picrylhydrazyl), and superoxide radical scavenging activities were increased and then reduced. An enhancement was noted in the coumaryloquinic acid I and II, caffeic acid glucoside, 4-hydroxybenzoic acid, and p-coumaric acid of SCCD-treated samples. The work demonstrated that the SCCD technique at moderate conditions could obtain higher retention of nutritional composition in fresh-cut pumpkins.

Fish waste oil extraction using supercritical CO2 extraction for biodiesel production: Mathematical, and kinetic modeling

The safe disposal of organic waste is a big environmental issue in landfills because of its huge generation volume. The main goal of this research is to determine the effect of supercritical carbon dioxide (scCO2) on the extraction of fish waste oil from discarded fish waste for producing biodiesel. Oil from fish waste was extracted using supercritical fluid extraction process using CO2 as a solvent. The supercritical carbon dioxide (scCO2) extraction was carried out with varying extraction pressure (10–40 MPa), temperature (32–80 °C), and treatment time (15–120 min). The maximum fish waste oil yield obtained was about 77.2 % at a temperature of 80 °C, a pressure of 30 MPa and a time of 60 min. The kinetics and thermodynamic behavior of the scCO2 extraction were calculated using Arrhenius law and Eyring theory, respectively. The estimated activation energy Ea value was 24.45 kJ/mol for the scCO2 extraction of discarded fish waste oil. Approximately 87 % of biodiesel was produced from scCO2 extracted oil via alkaline transesterification process with reaction temperature of 65 °C, NaOH loaded 1 wt%, fish oil to methanol molar ratio of 1:9, and treatment time of 3 h. The characterization of the produced biodiesel showed that its properties complied with the biodiesel standards (EN 14214 & ASTM D6751). The finding of this research revealed that the fish waste could be consumed as a biofuel feedstock.

The combined effect of supercritical carbon dioxide and mild temperatures on pectin methylesterase inactivation in orange juice.

Pectin methylesterase (PME) is the target-enzyme in orange juice processing, and its inactivation preserves the original juice's cloud, a valuable quality attribute for consumers. This study was primarily undertaken to evaluate the combination of supercritical carbon dioxide (SC-CO2) and mild temperatures on PME inactivation in the juice. Physicochemical and color parameters were also evaluated. Pressures (P) in the range of 74 to 351 bar, temperatures (T) between 33°C and 67°C, and holding times (t) varying from 20 to 70 min were tested using a central composite rotational design. Determination of PME activity, pH, titratable acidity, soluble solids, ratio, lightness, °hue and chroma in freshly extracted/raw and treated juice samples, and total color difference (TCD) between raw and treated juice were carried out. The percentage of PME reduction widely ranged from 13.7% to 91.8%. The variable P had a significant effect (p ≤ 0.05) on TCD and acidity variation. T exhibited a significant effect on the PME reduction, TCD, and soluble solids variation; however, t impacted on the soluble solids variation only. The interaction between P and t (P.t) affected the soluble solids and acidity variation, and T.t affected TCD. The combination of SC-CO2 and mild temperatures is potentially capable of inactivating PME in orange juice.

Supercritical carbon dioxide treatment of plum (Prunus domestica L) kernel protein isolate: Impact on structural, thermal, physical, and functional properties

The effects of supercritical carbon dioxide (SC–CO2) treatment at varying processing temperatures (30–70 °C) on the physicochemical, structural, thermal, and functional properties of plum kernel protein isolate (PKPI) were investigated. The results revealed that SC-CO2 treatment at 60 °C reduced α-helical content (67.82%) and increased the β-sheet content (33.15%), which resulted in the greater stabilization of the oil-water emulsion (1.29-fold), enhanced foaming capacity (2.08-fold) and improved the solubility (1.23-fold). The fluorescence quenching in SC-CO2 treated PKPIs confirmed the conformational change in protein structure. A significant variation in denaturation temperatures (74.53–66.20 °C) and enthalpy values (133.16–93.98 J/g) of SC-CO2 treated PKPIs, indicates protein denaturation and the formation of new intermolecular bonds between proteins molecules. Furthermore, SC-CO2 treatment reduced the particle size and exerted a greater homogeneity, thereby offering new opportunities to extend its use in food applications.

Structural modification of plum (Prunus domestica L) kernel protein isolate by supercritical carbon-dioxide treatment: Functional properties and in-vitro protein digestibility

The effect of supercritical carbon dioxide (SC-CO2) treatment at different processing temperatures (30–70 °C) on the physico-functional properties, structural features, and in-vitro digestibility (IVPD) of plum kernel protein isolates (PKPI) was examined. The results revealed remarkable changes in the secondary structures of SC-CO2-treated PKPIs, including a decrease in α-helix proportion, a concomitant increase in β-sheet content, and a considerable variation in random coils and β-turn structures. The temperature rise increased the negative zeta potential to a maximum of 31.35 mV at 60 °C, exhibiting the colloidal stability of PKPI dispersions. SDS-PAGE analysis showed variations in the intensities of protein bands, indicating denaturation and aggregation at higher temperatures. These structural and molecular changes improved water-binding capacity (1.22-fold) and oil binding capacity (1.11-fold), wettability (1.12-fold), and the highest value in all the properties was recorded at 60 °C. Moreover, the highest IVPD value (21.58 %) and a distinguishable colour difference (∆E) of 8.11 was also obtained at 60 °C of the processing temperature. Therefore, SC-CO2 treatment-induced modification of PKPI contributed to the enhanced digestibility and techno-functional properties, which offered new prospects to extend its use in food applications.

"Effect of supercritical carbon dioxide on vulcanization kinetics of silicone rubber"

"Effect of supercritical carbon dioxide on vulcanization kinetics of silicone rubber"

Effects of scCO2 foaming process and post‐vulcanization method on cellular structure, mechanical properties, and thermal stability of PMVQ foams

AbstractIn this paper, the microcellular foam materials of methyl vinyl phenyl silicone rubber (PVMQ) were prepared by supercritical foaming technology (SFT) and high temperature compression molding. The effect of supercritical carbon dioxide (scCO2) on the vulcanizing properties of PVMQ composite was investigated because vulcanization of microcellular PVMQ foams played an important role on the cellular structure and mechanical properties. It was found that the sulfurization reaction of PVMQ composite was inhibited by scCO2, which led to reduction of apparent activation energy (Ea) of PVMQ composite. Compared with the existing post‐vulcanization process, the introduction of the high temperature molding can effectively improve the degree of vulcanization of microcellular PVMQ foams, which can solve the problem that the cellular structure will be destroyed during the application of external force. What's more, the mechanical properties of microcellular PVMQ foam were obviously improved. The maximum value of tensile strength and the compressive strength of microcellular PVMQ foam with the high temperature molding respectively increase by 34.7% and 133.3% compared with that of microcellular PVMQ foams with existing post‐vulcanization.

Effect of supercritical carbon dioxide on bacterial community, volatile profiles and quality changes during storage of Mongolian cheese

Mongolian cheese was sterilized by using supercritical carbon dioxide (SC–CO2) treatment at three pressures (10, 15 and 20 MPa) and three temperatures (40, 50 and 60 °C). The optimum SC-CO2 condition (20 MPa and 60 °C) could achieve complete inactivation of bacteria. Preservation of Mongolian cheese was assessed at 25 °C for 20 d by analyzing texture, bacterial communities and volatile compounds, after using SC-CO2 (20 MPa and 60 °C). The results indicated that SC-CO2 treatment could maintain texture stability of Mongolian cheese during storage. High throughput sequencing results showed that Clostridium_sensu_stricto and Lysinibacillus were not detected in the SC-CO2 treated cheese and the total abundance of spoilage bacteria in the SC-CO2 treated cheese was much lower than that in untreated cheese after 20 days storage. Nine core functional bacteria such as Clostridium_sensu_stricto, Lysinibacillus, Pseudoclavibacter, Pseudomonas, Acinetobacter, Lactococcus, Aeromonas, Serratia and Buttiauxella that significantly affected the formation of volatile compounds were identified by Spearman correlation analysis. SC-CO2 treatment decreased the contents of volatile compounds (acids and esters) (p < 0.05), avoiding off-flavors development related to the volatile compounds of excess in Mongolian cheese during storage. Overall, SC-CO2 technology could be used as an effective tool to sterilize Mongolian cheese with minimal quality changes.

Effect of supercritical carbon dioxide on physicochemical and techno-functional properties of amaranth flour

Amaranth flour is a foodstuff with good quality protein that could be used to manufacture different products. The supercritical carbon dioxide (SC-CO2) treatment allows intensifying the extraction process for obtaining a flour without toxic residues and high-quality oil, replacing the use of organic solvent and reducing the extraction time. In this study, physicochemical and techno-functional properties of amaranth flour (Amaranthus hypochondriacus) defatted with SC-CO2 at different pressure conditions (2900-4350 psi) and temperatures (40-60°C) were determined. It was observed that extraction pressure and temperature had a significant effect (p<0.05) on the extraction yield and protein content, as well as the components present in the flour particles, causing differences in the physicochemical and techno-functional properties. The amaranth flour defatted with SC-CO2 at 50°C/3630 psi was the most outstanding as it had the best extraction performance (70.2 mg oil/g flour), the highest protein content (16.17 g protein/100 g flour), the swelling (SC) (2.263 g H2O/g flour), water absorption (WAC) (126.33 g H2O/100g flour), and oil absorption (OAC) (119.09 g oil/100g flour) capacities, high luminosity (L*) (82.89) and a high total color difference (ΔE*) (5.93). The fatty acid composition of the oils obtained by SC-CO2 showed high content of polyunsaturated fatty acids (PUFA). Physicochemical and techno-functional properties of amaranth flour changed by SC-CO2 treatment, flour defatted by SC-CO2 under intermediate conditions of temperature and pressure (50°C and 3630 psi), was able to produce a high-protein and low-fat amaranth flour as well as with good hydration techno-functional properties, which can be an alternative to defatting process with organic solvents.

Valorization of brewer’s spent grain by consecutive supercritical carbon dioxide extraction and enzymatic hydrolysis

The double effect of supercritical carbon dioxide, sc-CO2, in a biorefinery concept applied to brewer’s spent grain (BSG) was assessed in this work. Extraction conditions to remove and valorize the lipophilic fraction were studied (20–40 MPa and 40–80 °C) obtaining a maximum yield of 5.70 ± 0.07 g/100 gBSG at 80 °C and 40 MPa. High pressures and temperatures resulted in higher content of total phenolic and flavonoid compounds, as well as higher antioxidant capacity. It was observed an improvement of the enzymatic hydrolysis yield by cellulase in the sc-CO2 treated BSG compared to the non-treated. This improvement could be partially attributed to the removal of the lipid fraction and to morphological changes of BSG after sc-CO2. Based on this double benefit, sc-CO2 can play an important role on biomass valorization.

Effects of supercritical carbon dioxide under different conditions on mechanical properties and energy evolution of coal

Effects of supercritical carbon dioxide under different conditions on mechanical properties and energy evolution of coal

Effect of Supercritical Carbon Dioxide on the In Vivo Biocompatible and Resorptive Properties of Tissue-Specific Scaffolds from Decellularized Pig Liver Fragments

Effect of Supercritical Carbon Dioxide on the In Vivo Biocompatible and Resorptive Properties of Tissue-Specific Scaffolds from Decellularized Pig Liver Fragments

Experimental and Simulation of Supercritical Carbon Dioxide PLA Biocomposite Foamed

The use of PLA as a green substitute for conventional plastics has increased considerably as a result of increased awareness of the environmental effect of the use of petroleum-based plastics. However, some of the PLA properties including brittleness and sensitivity to high temperature and humidity, greatly restrict its application. The addition of reinforcement of low-cost natural fibres and foaming are considered to overcome the above disadvantages since it can improve some of PLA’s processing. This paper reported the effects of supercritical carbon dioxide (SCCO2) on the tensile strength of PLA biocomposite films produced via solution casting method. The biocomposite films underwent supercritical carbon dioxide (SCCO2) treatment at temperature of 40°C and pressure at 200 bar. The tensile strength showed that the PLA biocomposite foamed has improved by 16.18%. This is due to a good adhesion interfacial between fiber and polymer matrix. A simulation on tensile strength of the biocomposite foamed was also conducted using COMSOL Multiphysics software. The tensile strength resulted from this simulation is similar to the experimental value. Therefore, the experimental value is valid and satisfy. This also showed that SCCO2 treatment significantly improved the properties of PLA biocomposite films which could be an alternative in packaging industries.

Effect of Supercritical Carbon Dioxide (ScCO2) on the Microstructure of Bituminous Coal with Different Moisture Contents in the Process of ScCO2 Enhanced Coalbed Methane and CO2 Geological Sequestration

Water plays an important role in carbon dioxide (CO2) enhanced coalbed methane exploitation and CO2 geological sequestration at deep geological conditions. We performed mercury intrusion porosimetry, Fourier transform infrared spectroscopy, Raman spectroscopy, and X-ray diffraction analysis on coal samples with different moisture contents after supercritical carbon dioxide (ScCO2) treatment to study the effect of different moisture contents on deep coal seam treatment by ScCO2. Using these experimental techniques, the effects of ScCO2 treatment on the microstructure of coal samples with different moisture contents were obtained. The results showed that the combination of ScCO2 and water in coal samples can cause mineral dissolution, increase the damage degree of coal structural defects, reduce the number of aromatic structures and oxygen-containing functional groups, and then lead to the expansion of the pore and fracture volume, especially the micropore volume. Moreover, with increasing the moisture content, the micropore volume of the coal samples under ScCO2 interaction with the presence of water exhibited an increasing trend. The number of oxygen-containing functional groups in the coal samples decreased. The peak position difference (G – D1) decreased first and then plateaued, and when the moisture content was in the range of 5.85–7.19%, the damage degree reached the maximum. The effect of water and ScCO2 on the dissolution of clay minerals in the coal samples was greater than that on the carbonate minerals.

Viola odorata

This study aimed at examining the effect of supercritical carbon dioxide (ScCO2) extraction on the subsequent extraction of the Viola odorata polar bioactive components. The raw material was firs submitted to ScCO2 extraction for the extraction of the lipophilic fraction. Then the exhausted raw material was subjected to ultrasound-assisted extraction (UAE) and microwave-assisted extraction (MAE) in order to extract the polar components. ScCO2 extraction was performed under the pressure of 300 bar and at a temperature of 40 °C for 4 hours. In order to see the effect of ScCO2, the UAE and MAE (50% aqueous ethanol solution as solvent) were conducted on both exhausted (residue-after the ScCO2) and unexploited raw materials. Also, the impact of the various UAE and MAE conditions was tested. The UAE was conducted on two different temperatures (40 and 50 °C) at the constant extraction time (40 and 20 min). MAE was conducted on two different extraction powers (470 and 800 W) and at the constant extraction time (10 min). The results were focused on the content of total phenols, total flavonoids and antioxidant activity of the obtained extracts. The yield during the ScCO2 process was 1.43% (w/w). It was noted that the extracts obtained by applying UAE and MAE after the ScCO2 were noticeably richer in the content of total phenols. UAE conditions of 40 °C and 20 min showed the highest yield of total phenols, recording 70.38 mg GAE/g DE, while the MAE at the power of 470 W achieved 11.89% higher yield of polyphenols in residue extracts. The antioxidant activity has also been in correlation with the concentration of polyphenols.