Search Results (97)

This study investigates the sequential extraction of lipids and saponins from C. frondosa viscera. Lipids were extracted using supercritical carbon dioxide (scCO₂) in the presence of ethanol (EtOH) as a co-solvent. Subsequently, the lipid-extracted viscera underwent three saponin extraction approaches, scCO₂-scCO₂, scCO₂-EtOH, and scCO₂-hot water, resulting in saponin-rich extracts. Process parameter investigation for saponin extraction from scCO₂-defatted viscera revealed minimal effects of temperature, pressure, extraction time, static extraction, and EtOH concentration on saponin yields, allowing for milder operational conditions (35 °C, 20 MPa, 30 min dynamic extraction, 75% EtOH at 0.5 mL/min) to achieve energy-efficient recovery. Continuous EtOH feeding predominates the scCO₂ extraction of saponins. The sequential scCO₂ extraction of lipid and saponins yielded saponins at 9.13 mg OAE/g, while scCO₂ extraction of lipid followed by a 24 h 70% EtOH extraction of saponins achieved 16.26 mg OAE/g, closely matching the optimized ultrasonic-assisted extraction of saponins (17.31 mg OAE/g) from hexane-defatted samples. Antioxidant activities of saponin-rich extracts obtained in the sequential scCO₂-EtOH extraction (17.12 ± 4.20% DPPH scavenging) and the sequential scCO₂-scCO₂ extraction (16.14 ± 1.98%) were comparable to BHT (20.39 ± 0.68%), surpassing that of hexane-defatted ultrasonic extracts (8.11 ± 1.16%). The optimized scCO₂-EtOH method offers a sustainable alternative, eliminating toxic solvents while maintaining high saponin yields and bioactivity. Full article

In recent years, underground hydrogen storage (UHS) has become a hot topic in the field of deep energy storage. Green hydrogen, produced using surplus electricity during peak production, can be injected and stored in underground reservoirs and extracted during periods of high demand. A profound understanding of the mechanisms of the gas–water two-phase flow at the pore scale is of great significance for evaluating the sealing integrity of UHS reservoirs and optimizing injection, as well as the storage space. The pore structure of rocks, as the storage space and flow channels for fluids, has a significant impact on fluid injection, production, and storage processes. This paper systematically summarizes the methods for characterizing the micro-pore structure of reservoir rocks. The applicability of different techniques was evaluated and compared. A detailed comparative analysis was made of the advantages and disadvantages of various numerical simulation methods in tracking two-phase flow interfaces, along with an assessment of their suitability. Subsequently, the microscopic visualization seepage experimental techniques, including microfluidics, NMR-based, and CT scanning-based methods, were reviewed and discussed in terms of the microscopic dynamic mechanisms of complex fluid transport behaviors. Due to the high resolution, non-contact, and non-destructive, as well as the scalable in situ high-temperature and high-pressure experimental conditions, CT scanning-based visualization technology has received increasing attention. The research presented in this paper can provide theoretical guidance for further understanding the characterization of the micro-pore structure of reservoir rocks and the mechanisms of two-phase flow at the pore scale. Full article

This study was designed to investigate the immunostimulatory and anticancer efficacies of pectic polysaccharides from ginseng leaves treated using the high-pressure extraction method (HPEM). The isolation of polysaccharides using HPEM resulted in 1.35-fold higher polysaccharide yields than those obtained using the commonly used hot water extraction method. In addition, component sugar analysis of ginseng-leaf-derived polysaccharides (GLHP) showed the presence of nine different types of monosaccharides, including galacturonic acid, galactose, rhamnose, and arabinose, which are characteristic of pectic polysaccharides. In addition, GLHP effectively induced activation of the complement system, and macrophages stimulated with GLHP showed enhanced production of cytokines such as IL-6, IL-12, and TNF-α. Intravenous (i.v.) and oral administration (p.o.) of GLHP significantly increased the cancer-cell-killing ability of spleen-derived NK cells. In a lung-cancer-bearing mouse model using Colon26-M3.1 carcinoma, prophylactic i.v. and p.o. GLHP potently inhibited 95.2% and 33.5% of lung cancer, respectively. Furthermore, GLHP showed significant anticancer effects, even in mice with NK cell dysfunction, via the anti-asialo GM1 antibody. These effects may be related to the cancer-cell-killing effects of cytotoxic T lymphocytes (CTL). Therefore, GLHP, a polysaccharide isolated from ginseng leaves using HPEM, has a potent anticancer effect, and these effects are closely related to the stimulation of various immune factors. Full article

Atherosclerosis is a persistent inflammatory disorder influenced by oxidative stress and lipid imbalances, and it continues to be a major contributor to cardiovascular diseases. Rich in catechins and flavonoids, green tea pressurized hot water extract (GPHWE) demonstrated potent antioxidant activity through DPPH, ABTS, hydroxyl, and nitric oxide scavenging assays. In vitro, GPHWE protected RAW264.7 macrophages from oxidized LDL (Ox-LDL)-induced cytotoxicity and apoptosis by mitigating oxidative stress and enhancing cell survival. Animal studies using mice fed a high-fat diet (HFD) revealed notable improvements in lipid profiles, including decreases in total cholesterol, LDL, the atherosclerosis index (AI), the coronary risk index (CRI), and triglycerides, as well as lower levels of malondialdehyde (MDA), an indicator of oxidative stress. These results were comparable to those achieved with Simvastatin. Molecular docking studies indicated strong binding affinities of catechins to essential targets such as LOX-1, HMG-CoA reductase, caspase-3, and Nrf2, implying that the mechanisms of GPHWE involve antioxidant properties, regulation of lipids, and stabilization of plaques. The catechins of GPHWE, including epigallocatechin gallate (EGCG), epicatechin gallate (ECG), and epigallocatechin (EGC), were tentatively identified through qualitative analysis performed by UHPLC-QTOF-MS. This comprehensive approach positions GPHWE as a promising natural remedy for preventing atherosclerosis and reducing cardiovascular risk. Full article

This review highlights the recent advancements in extraction techniques for bioactive compounds from natural sources, focusing on methodologies that enhance both efficiency and sustainability. Techniques such as pressurized hot water extraction (PHWE), solid-state fermentation (SSF), ionic liquids (ILs), and electrohydrodynamic (EHD) methods have shown significant potential in improving extraction yields while preserving the bioactivity of target compounds. These innovative approaches offer significant advantages over traditional methods, including reduced energy consumption, minimal environmental impact, and the ability to extract thermosensitive compounds. PHWE and EHD are particularly effective for extracting antioxidants and thermosensitive compounds, whereas SSF provides an environmentally friendly alternative by valorizing agro-industrial waste. Ionic liquids, although promising for extracting complex phytochemicals, face challenges related to scalability and economic feasibility. The adoption of these advanced techniques represents a shift toward more sustainable and cost-effective extraction processes, promoting the discovery and utilization of high-value compounds. These methods also contribute to the development of eco-friendly, cost-effective strategies that align with green chemistry principles and regulatory standards. However, further research and technological advancements are required to address existing limitations and ensure the widespread application of these methods in industrial and pharmaceutical sectors. Full article

Geothermal energy can be obtained from hot dry rock (HDR). The target temperatures for heat extraction from HDR range from 100 to 400 °C. Artificial fracturing is employed to stimulate HDR and create a network of fractures for geothermal resource extraction. Liquid nitrogen (LN₂) is environmentally friendly and shows better performance in reservoir stimulation than does conventional fracturing. In this study, triaxial compression experiments and acoustic emission location techniques were used to evaluate the impacts of temperatures and confining pressures on the mechanical property deterioration caused by LN₂ cooling. The numerical simulation of LN₂ fracturing was performed, and the results were compared with those for water and nitrogen fracturing. The results demonstrate that the confining pressure mitigated the deterioration effect of LN₂ on the crack initiation stress, crack damage stress, and peak stress. From 20 to 60 MPa, LN₂-induced reductions in these three stress parameters ranged between 7.73–18.51%, 3.46–12.15%, and 2.51–8.50%, respectively. Cryogenic LN₂ increased the number and complexity of cracks generated during rock failure, further enhancing the fracture performance. Compared with those for water and nitrogen fracturing, the initiation pressures of LN₂ fracturing decreased by 61.54% and 68.75%, and the instability pressures of LN₂ fracturing decreased by 20.00% and 29.41%, respectively. These results contribute to the theoretical foundation for LN₂ fracturing in HDR. Full article

Cooling small components is becoming an attractive topic for researchers. In this paper, an attempt is made to use an ethylene glycol/water mixture as a cooling liquid. This liquid is a helpful application for when the fluid is in a harsh environment and should not freeze. The experiment uses an ethylene glycol/water mixture circulating through a triply periodic minimal surface structure (TPMS) made of aluminum and silver. A constant heat flux equal to 38,000 W/m² is applied, and three different flow rates, 11.8 cm³/s, 15.5 cm³/s, and 19.6 cm³/s, are studied. The experimental setup is complemented with numerical modelling by solving the Navier–Stokes equation and the energy equation using the finite element technique. The flow is Newtonian, and a laminar regime is implemented. Results reveal that the performance of the ethylene glycol/water mixture did not enhance heat removal when compared to water. The average Nusselt number is similar regardless of the concentration of ethylene glycol in the mixture. This average Nusselt number, Nu_average, in the presence of aluminum TPMS ranges between 60 and 80 (60 < Nu_average < 80) and between 65 and 85 (65 < Nu_average < 85) using silver TPMS. The increase in the mixture’s viscosity due to ethylene glycol increased the pressure drop. The performance evaluation criteria reach the maximum value of 90 when the mixture is composed of 5%vol ethylene glycol in water with aluminum TPMS. In the presence of silver TPMS, the maximum performance evaluation criterion is around 95 with a 5% ethylene glycol/water mixture. Finally, it is proven experimentally and confirmed numerically that the TPMS structure secures uniform heat extraction from the hot surface. Full article

Citrus fruits are widely distributed in East Asia, and tea made from citrus peels has demonstrated health benefits, such as a reduction in fever, inflammation, and high blood pressure. However, citrus leaves have not been evaluated extensively for their possible health benefits. In this study, the α-glucosidase-inhibitory activity of Jeju citrus hot-water (CW) and ethyl alcohol (CE) extracts, along with hesperidin (HP) (a bioactive compound in citrus leaf extracts), was investigated, and furthermore, their effect on postprandial blood glucose reduction in an animal model was determined. The hesperidin contents of CW and CE were 15.80 ± 0.18 and 39.17 ± 0.07 mg/g-extract, respectively. Hesperidin inhibited α-glucosidase (IC₅₀, 4.39), sucrase (0.50), and CE (2.62) and demonstrated higher α-glucosidase inhibitory activity when compared to CW (4.99 mg/mL). When using an SD rat model, during sucrose and starch loading tests with CE (p < 0.01) and HP (p < 0.01), a significant postprandial blood glucose reduction effect was observed when compared to the control. The maximum blood glucose levels (Cmax) of the CE administration group decreased by about 15% (from 229.3 ± 14.5 to 194.0 ± 7.4, p < 0.01) and 11% (from 225.1 ± 13.8 to 201.1 ± 7.2 hr·mg/dL, p < 0.05) in the sucrose and starch loading tests, respectively. Our findings suggest that citrus leaf extracts standardized to hesperidin may reduce postprandial blood glucose levels through the observed inhibitory effect against sucrase, which results in delayed carbohydrate absorption. Our findings provide a biochemical rationale for further evaluating the benefits of citrus leaves. Full article

Flavonoids are the most abundant functional compounds distributed in higher plants, and are used as important dietary components for human health protection. The development of natural flavonoids, such as functional food or medicinal food, has received extensive attention in recent years. The extraction, separation, and quantitation of flavonoids are the key techniques in the utilization of flavonoid resources. The traditional methods for flavonoid extraction and separation always used toxic solvents, which produce toxic residues and pollute the environment. Based on an analysis of the literature on flavonoid resources, the utilization, separation, quantitation, and green separation techniques of flavonoids were summarized. First, extraction by hot water or hot ethanol, assisted by pressurization and microwave-ultrasonication, then concentration and precipitation of flavonoids by cool water or cool ethanol or ethanol/water in specific ratios. This method could obtain over 85% purity in the first cycle and over 95% purity after three precipitation cycles in the separation of the most commonly used flavonoids, such as dihydromyricetin, rutin, and quercetin. In conclusion, flavonoids showed great prospects in human health protection and disease treatment. Chemical structure-based separation using the water–ethanol methods and assisted with microwave-ultrasonication, pressurization, and temperature regulation proved to be efficient and environmentally friendly, showing great potential for the flavonoid industry. These “green” processing techniques and mechanisms deserve further research. Full article

Mitragyna speciosa Korth. Havil (MS) has a traditional use in relieving pain, managing hypertension, treating cough, and diarrhea, and as a morphine substitute in addiction recovery. Its potential in addressing Alzheimer’s disease (AD), a neurodegenerative condition with no effective treatments, is under investigation. This study aims to explore MS mechanisms in treating AD through network pharmacology, molecular docking, and in vitro studies. Using network pharmacology, we identified 19 MS components that may affect 60 AD-related targets. The compound–target network highlighted significant interactions among 60 nodes and 470 edges, with an average node degree of 15.7. The KEGG enrichment analysis revealed Alzheimer’s disease (hsa05010) as a relevant pathway. We connected 20 targets to tau and β-amyloid proteins through gene expression data from the AlzData database. Docking studies demonstrated high binding affinities of MS compounds like acetylursolic acid, beta-sitosterol, isomitraphylline, and speciophylline to AD-related proteins, such as AKT1, GSK3B, NFκB1, and BACE1. In vitro studies showed that ethanolic (EE), distilled water (DWE), and pressurized hot water (PHWE) extracts of MS-treated 100 μM H₂O₂-induced SH-SY5Y cells significantly reduced oxidative damage. This research underscores the multi-component, multi-target, and multi-pathway effects of MS on AD, providing insights for future research and potential clinical applications. Full article

Generally, the extraction method has a great influence on the quality of pectin. However, there is little study on the effect of extraction method on the properties of Choerospondias axillaris fruit pulp pectin (CAPP). Accordingly, the physicochemical, structural, and functional properties of CAPP extracted by hot water (HWE), hydrochloric acid (HAE), ultrasound (UAE), and ultrahigh pressure (UPE) were investigated. Among these four CAPPs, UPE had the highest yield (15.79%) and GalA content (60.44%). UAE showed the most abundant side chains and RG-I region (55.12%). The lowest molecular weight (233.13 kDa) and yield (8.64%) were found in HAE. Though HWE exhibited better yield than HAE, its Mw was the highest. Different from physicochemical characteristics, the extraction method had a small effect on the structure of CAPP. The crystalline structure and functional group composition of different CAPPs were similar, while the surface structure of UAE and UPE had irregular circular holes in comparison with HWE and HAE. Furthermore, the extraction method also showed a great impact on the function. Compared with HWE and HAE, UAE and UPE presented better thermal stability and emulsifying properties. Meanwhile, HAE and UAE showed better antioxidant ability and prebiotic properties among these four CAPPs. The above results indicated that UAE showed better yield and functional properties. Hence, ultrasound extraction could be used as an effective method to extract CAPP. Full article

This study explores the hydrothermal carbonization (HTC) process applied to the exhausted chestnut produced by the tannin extraction industry, utilizing process water recirculation to enhance the efficiency and sustainability of the conversion process. Tannin extraction from wood typically involves hot water treatment, leaving behind residual wood biomass known as exhausted wood. These by-products maintain their renewable properties because they have only been exposed to hot water under a high pressure, which is unlikely to cause major alterations in their structural components. Hydrothermal treatment was carried out at temperatures of 220 °C and 270 °C for 1 h, with process water being recirculated four times. This investigation focused on analyzing the effects of recirculation on the yield and fuel properties of hydrochar, as well as characterizing the combustion behavior of the obtained hydrochar. The results indicated that recirculation of process water led to improvements in both the mass and energy yields of hydrochar. The mass yield of the hydrochar samples increased by 5–6%, and the ERE of the hydrochar samples increased by 5–8% compared to the HTC reference sample. However, alterations in the combustion characteristics were observed, including decreases in ignition temperature and combustion reactivity. The results indicate that, with PW recirculations, the combustion index decreased by about 14% and 18% for 220 °C and 270 °C, respectively. Overall, this research demonstrates the potential of utilizing HTC on chestnut tannin residue with process water recirculation to produce stable solid fuel and provides insights into the combustion behavior of the resulting hydrochar. Full article

Ugni candollei, commonly known as white murta, is a native Chilean berry with a polyphenol composition that has been underexplored. This study aimed to establish a comprehensive profile of white murta polyphenols using ultra-performance liquid chromatography electrospray ionization Orbitrap mass spectrometry (UPLC-ESI-ORBITRAP MS). Additionally, it compared the efficacy of conventional extraction methods with emerging techniques such as deep eutectic solvent (DES) extraction and hot pressurized water extraction (HPWE). The analysis tentatively identified 107 phenolic compounds (84 of them reported for the first time for this cultivar), including 25 phenolic acids, 37 anthocyanins, and 45 flavonoids. Among the prominent and previously unreported polyphenols are ellagic acid acetyl-xyloside, 3-p-coumaroylquinic acid, cyanidin 3-O-(6′-caffeoyl-glucoside, and phloretin 2′-O-xylosyl-glucoside. The study found HPWE to be a promising alternative to traditional extraction of hydroxybenzoic acids, while DES extraction was less effective across all categories. The findings reveal that white murta possesses diverse phenolic compounds, potentially linked to various biological activities. Full article

The Kenyan part of the East African Rift System hosts several geothermal fields for energy production. Changes in the extraction rate of geothermal fluids and the amount of water re-injected into the system affect reservoir pressure and production capacity over time. Understanding the balance of production, natural processes and the response of the geothermal system requires long-term monitoring. The presence of a geothermal system at depth is often accompanied by surface manifestations, such as hot water springs and fumaroles, which have the potential for monitoring subsurface activity. Two thermal camera timelapse systems were developed and installed as part of a multi-sensor observatory in Kenya to capture fumarole activity over time. These cameras are an aggregation of a camera unit, a control unit, and a battery charged by a solar panel, and they monitor fumarole activity on an hourly basis, with a deep sleep of the system in between recordings. The article describes the choice of hardware and software, presents the data that the cameras acquire, and discusses the system’s performance and possible improvement points. Full article

This study evaluated the effects of different drying techniques on the physicochemical properties of Pleurotus citrinopileatus Singer (P. citrinopileatus), focusing on the ergothioneine (EGT) contents. The P. citrinopileatus was subjected to natural ventilation drying (ND), freeze-drying (FD), and hot-air drying (HD). EGT was extracted using high-hydrostatic-pressure extraction (HHPE), and response surface methodology (RSM) was employed with four variables to optimize the extraction parameters. The crude EGT extract was purified by ultrafiltration and anion resin purification, and its antioxidant activity was investigated. The results showed that the ND method effectively disrupted mushroom tissues, promoting amino acid anabolism, thereby increasing the EGT content of mushrooms. Based on RSM, the optimum extracting conditions were pressure of 250 MPa, extraction time of 52 min, distilled water (dH₂O) as the extraction solvent, and a 1:10 liquid–solid ratio, which yielded the highest EGT content of 4.03 ± 0.01 mg/g d.w. UPLC-Q-TOF-MSE was performed to assess the purity of the samples (purity: 86.34 ± 3.52%), and MS² information of the main peak showed primary ions (m/z 230.1) and secondary cations (m/z 186.1050, m/z 127.0323) consistent with standard products. In addition, compared with ascorbic acid (VC), EGT showed strong free radical scavenging ability, especially for hydroxyl and ATBS radicals, at more than 5 mmol/L. These findings indicate that the extraction and purification methods used were optimal and suggest a possible synthetic path of EGT in P. citrinopileatus, which will help better explore the application of EGT. Full article