High Extraction Rate Research Articles

Ultrasound-assisted extraction of sumac fruit oil and analysis of its fatty acid composition.

The use of ultrasound for enhancing the extraction of sumac fruit oil was investigated to maximize the utilization of available sumac fruit resources. The optimal extraction parameters were determined using single-factor trials and Box-Behnken design optimization and were found to be a liquid-to-material ratio of 13:1mL/g, an ultrasound temperature of 47°C, and an ultrasound duration of 32min. These yielded a 20.59% extraction rate of the oil. The ultrasonic-assisted approach markedly increased the extraction rate and significantly reduced the extraction time when compared to classical Soxhlet extraction. The resulting sumac fruit oil had a brown-yellow color with peroxide, acid, and iodine concentrations of 2.43mg/g, 0.44g/100g, and 135g/100g, respectively, and relative density (d20 20), and refractive index (20°C) values of 0.911, and 1.469, respectively. The primary fatty acids in the oil were stearic, linoleic, palmitic, linolenic, and oleic acids. With a 74.14% unsaturated fatty acid content, it has a high nutritional value as well as significant development and usage potential. PRACTICAL APPLICATION: This study demonstrates a highly efficient method for extracting vegetable oils and fats. It has the advantages of simple operation, low extraction temperature, short extraction time, high extraction rate, no damage to the material structure, excellent phusicai and chemical properties of the extracted vegetable oil, low cost, and the potential application in the food industry is crucial.

Novel Indigenous Strains and Communities with Copper Bioleaching Potential from the Amolanas Mine, Chile

Bioleaching, a process catalyzed by acidophilic microorganisms, offers a sustainable approach to metal extraction from sulfide minerals. Chalcopyrite, the world’s most abundant copper sulfide, presents challenges due to surface passivation limiting its bioleaching efficiency. Also, indigenous species and microbial communities may present high copper extraction rates and offer new possibilities for application in bioleaching processes. This study examines the bioleaching potential of microbial isolates and communities obtained from Amolanas Mine in Chile. Samples were collected, cultivated, and identified by Sanger sequencing. The bioleaching potential and biofilm formation of isolates and enrichments were evaluated on pyrite and chalcopyrite. The results show the isolation of nine Leptospirillum and two Acidithiobacillus strains. The bioleaching experiments demonstrated good copper bioleaching potentials of the Leptospirillum I2CS27 strain and EICA consortium (composed mainly of Leptospirillum ferriphilum, Acidiphilium sp., and Sulfobacillus thermosulfidooxidans), with 11% and 25% copper recovery rates, respectively. Microbial attachment to the surface mineral was not mandatory for increasing the bioleaching rates. Our findings underscore the importance of indigenous microbial communities in enhancing copper bioleaching efficiency.

Kinetics, thermodynamics, and optimization analyses of lipid extraction from discarded beef tallow for bioenergy production

ABSTRACT The wide expansion of the meat industry generated tremendous amounts of animal-based waste. Discarded beef tallow (DBT) is one of those prevalent lipid-rich wastes disposed of by slaughterhouses, meat processing units, and tanneries. The current study utilized the advanced technology of supercritical CO2 (SC-CO2) to extract lipid content from DBT for biodiesel production through transesterification. The effects of SC-CO2 parameters on the extraction rate were investigated over ranges of (32–80°C) for temperature, (10–50 MPa) for pressure, and (15–150 min) for treatment time. Using response surface methodology (RSM), both processes of SC-CO2 and transesterification were optimized. The highest extraction rate was 86.10%, obtained at the experimental conditions of 60°C for temperature, 30 MPa for pressure, and 120 min for treatment time. For the transesterification, the maximum yield of biodiesel was 95.15%, obtained at the reaction conditions of 1:7.5, 1.16 wt%, 58°C, and 72 min for lipid to methanol molar ratio, catalyst ratio, temperature, and time, respectively. The outcomes of the kinetic and thermodynamic analyses showed that the SC-CO2 extraction was an endothermal, unspontaneous, and temperature-dependent process. The characteristics of the synthesized biodiesel largely comply with the ASTM D6751 and EN 14,214 standards. The findings of the current study confirm the viability of SC-CO2 to extract lipids from DBT as a low-cost feedstock for biodiesel production.

Extraction and Structural Analysis of Sweet Potato Pectin and Characterization of Its Gel.

Pectin is widely used in the food and pharmaceutical industries. However, data on sweet potato pectin extraction and structural property analyses are lacking. Here, for the high-value utilization of agricultural processing waste, sweet potato residue, a byproduct of sweet potato starch processing, was used as raw material. Ammonium oxalate, trisodium citrate, disodium hydrogen phosphate, hydrochloric acid and citric acid were used as extractants for the pectin constituents, among which ammonium oxalate had a high extraction rate of sweet potato pectin, low ash content and high molecular weight. Structural and gelation analyses were conducted on ammonium oxalate-extracted purified sweet potato pectin (AMOP). Analyses showed that AMOP is a rhamnogalacturonan-I-type pectin, with a molecular weight of 192.5 kg/mol. Chemical titration and infrared spectroscopy analysis confirmed that AMOP is a low-ester pectin, and scanning electron and atomic force microscopy demonstrated its linear molecular structure. Gelation studies have revealed that Ca2+ is the key factor for gel formation, and that sucrose significantly enhanced gel hardness. The highest AMOP gel hardness was observed at pH 4, with a Ca2+ concentration of 30 mg/g, pectin concentration of 2%, and sucrose concentration of 40%, reaching 128.87 g. These results provide a foundation for sweet potato pectin production and applications.

Research on the Supercritical CO2 Extraction Process of Hetian Rose Essential Oil

A longstanding concern in plant essential oil extraction is how to optimize extraction efficiency with limited materials. Supercritical CO2 extraction has been proven effective in enhancing the yield and efficiency of extracting plant essential oils. However, the impact of temperature, pressure, and co-solvent content on extracting Hetian rose essential oil remains unclear. There is a lack of research on the influence of pretreatment methods. This study focuses on investigating supercritical CO2 extraction of rose essential oils from Xinjiang Hetian. The research analyzes the effects of pressure and temperature on the extraction rate and validates the efficiency by calculating the solubility of essential oils in supercritical fluid. Under conditions of 35 MPa, 40 °C, 10 L/h, and a particle size of 0.8 mm, this study evaluates the extraction efficiency using Xinjiang Hetian rose materials pretreated with salt solutions at concentrations of 5%, 10%, and 20%, as well as enzyme solutions at concentrations of 2%, 5%, and 10%. Results indicate that appropriate solution concentration can enhance the extraction effect and mass transfer process, but excessively low or high concentrations do not contribute to improved extraction reactions. The highest extraction rate (8.99%) is achieved using a salt solution concentration of 10%, while the lowest (4.21%) is obtained with a salt solution concentration of 20%.

Perceptions on the environmental impacts of illegal river sand mining in the Limpopo Province, South Africa

Illegal river sand mining in regions like the Limpopo Province poses severe threats to ecosystems and communities. Nevertheless, the community's perspectives concerning these effects have not been determined. Thus, the aim of the investigation was to assess community perceptions regarding the environmental consequences linked to river sand mining in the Limpopo Province, South Africa. The study employed mixed methods to acquire the primary data. The quantitative data were acquired using questionnaires; meanwhile, the qualitative data were collected through semi-structured interviews from various respondents. The demographic profile of the respondents indicated a predominantly male population, with a majority lacking formal qualifications. Additionally, the prevalence of very high unemployment rates in the area seemed to influence participation in the activity. Consequently, some perceived it as an economic opportunity to generate income for their sustenance. It has been found that as developments increase, the demand for river sand increases as well, leading to a high extraction rate of sand. Lastly, the extraction of the resources was found to be un-regulated or controlled; therefore, it is concluded that unregulated extraction of these resources resulted in a high extraction rate and environmental crises such as un-rehabilitated pits, water pollution, land pollution, among others. It is therefore recommended that collaborative efforts among relevant authorities to enforce stringent regulations and penalties. Equally vital are public awareness campaigns, which can play a pivotal role in educating communities about the environmental repercussions of illegal sand mining.

A high-permeability method for extracting purple yam saponins based on ultrasonic-assisted natural deep eutectic solvent

The extraction of active ingredients from traditional Chinese medicine has received considerable attentions. In this study, 16 kinds of natural deep eutectic solvent (NADES) with ultrasonic were selected to extract saponins from purple yam root and the extraction mechanism was investigated. The results showed that chloride/acrylic acid (1:2; n/n) had the highest extraction yield for saponins. The optimal extraction process parameters were 24% water content, 20 mL/g liquid-solid ratio, and ultrasonic extraction for 85 min (81 °C, 600 W). The extraction rate (ER) of purple yam saponins was 0.935%, close to the fitted result of 96.5 mg/g. Molecular dynamics simulations and FT-IR results showed that the NADES may extract the saponin constituents from purple yam through hydrogen bonding. Compared with traditional extraction methods and molecularly imprinted polymer methods, NADES has a higher ER and lower cost (1.53 $/g), which provides a reference for subsequent industrial quantitative production.

Nano temperature-switchable supramolecular solvent: Preparation, characterization and application in efficient extraction and enrichment of phytochemicals

In this study, a nano temperature-switchable supramolecular solvent (NTS-SUPRAS) system was designed, prepared and characterized for efficient extraction and enrichment of phytochemicals, the extraction mechanism was also investigated. The NTS-SUPRAS was synthesized by natural deep eutectic (NADES), 1,2-Propanediol and water, then the ternary phase diagrams were plotted according to their mass fractions. Dynamic light scattering (DLS), conductivity and FT-IR were used to characterize the solvent, and an exciting discovery was the nanoscale of NTS-SUPRAS. The particle size of its reverse micelles self- aggregated was positively correlated to the water content, which was increased from 3.8 nm to 77.9 nm as the water content increased from 5 % to 20 %. Temperature-switchable of NTS-SUPRAS was proved by the appearance of phase separation when regulate temperature from 25 °C to 10 °C. Then, six phytochemicals in Cajanus cajan(Linn.) leaves were efficiently extracted and enriched by vortex-assisted extraction. The extraction factors such as solid–liquid ratio, vortex time, NADES content and water content were optimized using the one-factor optimization method and response surface analysis to obtain the optimal extraction conditions. The results showed that the extraction efficiency of NTS-SUPRAS was 1.18–2.32 folds higher than that of traditional solvents for different polar substances, and the total extraction yield could be reached 21.13 mg/g. The phytochemicals were highly recovered by temperature-switching and macroporous adsorption resin with a recovery rate up to 98.6 %, and the reusability of NTS-SUPRAS could still keep at 90.43 % of the initial one after three cycles. Finally, the extraction mechanism of NTS-SUPRAS was investigated using density functional theory (DFT), founding that the hydrogen bonding between NTS-SUPRAS and the phytochemicals was attributed to the high extraction rate. This nano temperature-switchable supramolecular solvent has the advantages of green, low cost, simple preparation, high extraction rate, easy recycling and good reusability, which is suitable for industrialized application and production. In addition, the nanoscale and the temperature-switchable characteristics also provide new prospects for high-value utilization of phytochemicals.

Cyclic redox strategy for sustainable recovery of lithium ions from spent lithium iron phosphate batteries

The growth of spent lithium-ion batteries requires a green recycling method. This paper presents an innovative hydrometallurgical approach in light of redox flow batteries, which employed Fe3+/Fe2+ as regenerative redox mediator to selectively extract Li+ from LiFePO4. In contrast to the conventional method in which the oxidizer is disposable, the present scheme allows for the recycling of the oxidizer, which demonstrates the advantages of environmentally friendly, low cost and higher extraction rate, offering a novel approach to recycling spent batteries.

Australian critical metal exploration for analogues of Chinese ionic-clay REE deposits

The clean energy transition has focused attention on the critical metals required for manufacture of new energy technologies. The extremely heterogeneous distribution of critical metal mineral deposits requires that countries must make new discoveries of key critical metals to avoid potential future geopolitical risks. Although Australia has REE resources, they are mainly of LREEs, so deposit styles with significant HREEs are key targets. The most obvious are the so-called ionic-clay REE deposits of southern China that are the major global suppliers of HREEs. Mineral exploration in Australia using the Chinese model is producing hitherto unrecognized REE concentrations, here termed regolith-hosted REE mineralization, in a variety of regolith types in several weathering environments, particularly in Western and South Australia. Amongst these has been the discovery of near-surface, regolith-hosted REE mineralization in the Albany-Fraser Orogen which has the potential to complement REE production from the giant Mount Weld carbonatite and other monazite-sand deposits in Western Australia. Widespread near-surface, regolith-hosted REE mineralization is present over an area of 12,000 km2 in the Esperance District. As much of this area is beneath barren Eocene-aged cover clays, all the new REE discoveries have been made, and are being delineated using shallow drilling, to depths of less than 80 m. The exploration implication is that the search space for regolith hosted REE deposits in Western Australia remains immature. These recently discovered deposits have both similarities and contrasts with geological features of ionic clay hosted REE deposits in China. Similarities include their apparent paragenesis and geometry, particularly their blanket morphology, sub-horizontal and gentle dips, and the common, but not exclusive, relationship with felsic basement terranes. However, Western Australian prospects are related to Upper Cretaceous to Eocene climates rather than more recent weathering under sub-tropical conditions. Whether the deposits can be developed to production remains unclear, with project economics tied closely to the efficacy of mineral processing technologies that target high REE extraction rates and recoveries.

Characterization of acid-soluble collagen (ASC) derived from walleye pollock and silver carp skin and comparison them with the collagen from pig and duck skin

The acid-soluble collagens (ASC) extracted from the skins of walleye pollock and silver carp were compared with ASCs from skins of duck and pig in physicochemical properties. The dry weight extraction rates of ASCs from walleye pollock and silver carp were 14.10 % and 10.30 %, which were significantly higher than those of pig and duck (4.53 % and 3.14 %). It was found that the ASCs from skins of pig, walleye pollock and silver carp were all type I collagen with intact triple helix structure, while ASC from duck skin was a mixture of type I and type II collagen.The PI of the four ASCs was in the weakly acidic range (5.49–6.84), but ASCs from two fish skins were less thermally stable than that from pig and duck. The dynamic frequency scanning showed that collagen from porcine skin always maintained elastic behavior, while the other three ASCs changed from viscous behavior to elastic behavior with the increasing of frequency. The collagen from two fish skins had a less dense microstructure. The high extraction rate proved that two fish skins were high-quality raw materials for collagen, and the differences in physicochemical properties allowed fish skin collagen to have different applications than terrestrial animal collagen.

Efficient extraction of Au(Ⅲ) by a piperidine-based ionic liquid and exploration of the mechanism driving force

Efficient gold extraction is of paramount importance, but how to improve the extraction efficiency and enhance the driving force of the extraction process is still to be explored. This study introduces an innovative approach using versatility ionic liquids (ILs) to overcome existing challenges. A tailored IL was synthesized and employed computational tools, including the Interaction Region Indicator, to predict its effectiveness in gold extraction. Quantum chemical calculations elucidated the interplay between hydrogen bonding capability and ion exchange properties of the ILs. Subsequent optimization of experimental conditions (0.1 mol/L HCl, 10.6 mg IL) yielded a remarkable 98.4 % extraction efficiency at 45 °C. Molecular dynamics simulations affirmed the IL's exceptional selectivity for Au(III) extraction, with analysis revealing that the extraction mechanism primarily hinged on electrostatic attraction and van der Waals interactions between ionic liquid cations and [AuCl4]−. This mechanism aligns with the established anion exchange mechanism, validated through Ultraviolet–visible spectrometer (UV–Vis), Nuclear Magnetic Resonance spectrometer (NMR), and Liquid Chromatograph Mass Spectrometer (LC-MS) analyzes. To complete the extraction cycle, 1.0 mol/L K2C2O4 was employed as a stripping agent for efficient Au(III) recovery from the loaded IL phase, facilitating repeated extraction cycles. This study underscores the sustainability of the IL-based Au(III) extraction process, maintaining consistently high extraction rates even after five cycles. In summary, this method does not use solvent, enabling environmentally friendly Au(III) extraction.

Chestnut shell dyes extracted by deep eutectic solvent in green dyeing of silk fibers for enhanced washable, antibacterial and UV protection properties

As an important biomass resource, chestnut shells are often discarded and wasted. In this study, we report an innovative, low-cost and environmentally friendly approach of dyeing silk fibers with natural pigments extracted from chestnut shells using deep eutectic solvent (DES) and imbuing them with antibacterial and ultraviolet protection properties. To improve the extraction ratio of chestnut shell pigment, DES of choline chloride and urea (ChCl/Urea) with high solubility performance was adopted to extract pigment from chestnut shells and then directly used for silk dyeing. The color spectral curve, washing durability, antibacterial and ultraviolet resistance of dyed silk were tested and compared with the silk dyed by metal salt mordant. The result showed that compared with ethanol extraction, DES extraction method had a higher extraction rate and better stability of the extraction solution. Owing to the swelling, surface modification and high permeability of ChCl/Urea DES to silk fibers, the affinity between the pigment solution and silk fibers was enhanced, and the pigment molecules entered the amorphous area inside the silk fibers, forming a tight bond with the fiber matrix during dyeing. Therefore, the dyed silk fabric has excellent washing durability and soft luster, and the color strength (K/S) remained unchanged after three washings. Meanwhile, the antibacterial activity and ultraviolet protection coefficient of silk dyed with chestnut shell pigment reached above 97% and 42.26, respectively, which exhibits excellent antibacterial and ultraviolet protection properties.

Chemical Composition Study of Three Varieties of Date seeds (Iraqi, Saudi and Yemeni) and their Utilization as caffeine-free coffee alternative

The study aimed to investigate the chemical composition of three widely available types of date seed in the Yemeni market (Iraqi, Saudi, and Yemeni) and their potential use as caffeine-free coffee alternative. Quantitative estimation was conducted for moisture, ash, protein, fiber, fat, carbohydrates, and caffeine, along with a descriptive estimation for alkaloids, tannins, and resins. Date seed coffee was prepared and sensory evaluation was performed by trained panelists. The results showed that Yemeni date seeds had the highest extraction Rate on average (30%), while Saudi date seeds had higher moisture, protein, fat, and fiber contents on average (8.997, 6.897, 11.167, and 16.333%, respectively). Yemeni date seeds contained the highest carbohydrate content on average (58.290%). All tested date seeds were caffeine-free, while the chemical composition for Yemeni coffee were 7, 0.9, 13.9, 14.4, 12.8, 4.1, and 1.5% for moisture, ash, protein, fat, fiber, carbohydrates, and caffeine, respectively. Descriptive estimation results showed the absence of alkaloids in all date seeds and coffee samples, with the presence of both tannins and resins. For sensory evaluation indicated high values for all attributes of date seeds coffee alternative, with Saudi date seeds coffee outperforming other types, suggesting its potential use as a caffeine-free coffee alternative and its associated health benefits.

Simultaneous and selective extraction of different polarity bioactive substances from Ligustri Lucidi Fructus based on a designable biphasic deep eutectic solvent

Most plants contain hydrophilic and hydrophobic bioactive compounds, traditional organic solvent extraction processes can often only extract one of the components, resulting in a cumbersome process and a waste of resources. To make full use of the active resources in Ligustri Lucidi Fructus, a biphasic deep eutectic solvent (DES) system was established. By adjusting the polarity, oleanolic acid (OA) and ursolic acid (UA) were enriched in the hydrophobic phase, and flavonoids and procyanidine (PAC) in the hydrophilic phase, respectively. Established with a 1:1 vol ratio of hydrophobic DES MIA (DL-menthol: isopropyl alcohol, 1:1) and hydrophilic DES CBE (choline chloride: betaine: ethylene glycol, 1:1:2). The biphasic system had the highest extraction rate. The response surface method was used to further optimize the extraction conditions. After optimization, the extraction yields of OA and UA were 10.96 ± 0.35 mg/g and 11.67 ± 0.26 mg/g in the MIA phase, and the extracted yields of flavonoids and PAC in the CBE phase were 77.38 ± 0.62 mg/g and 5.20 ± 0.03 mg/g, respectively. Compared with the conventional single-phase extraction with organic solvents, the biphasic system provided higher extraction rate and selectivity and the extracts showed stronger antioxidant activity. Compared to the single-phase extraction utilizing conventional organic solvents, the results demonstrated significant improvement. Consequently, by adjusting the polarity of the biphasic DES system, this study supplies an argument for increasing the extraction efficiency of plant resources. This expands the application of the biphasic DES system and contributes to the high-value exploitation of natural commodities.

Selective extraction of lithium ions by phosphoroxy-functionalized ionogels from the mother liquor of Li2CO3

Functionalized ionic liquids (FILs), as novel extractants, offer a promising way for the effective separation of Li+, but are limited by their high viscosity which increases the mass transfer resistance and hinders their practical application in industry. To overcome the above problem, this work develops a phosphoroxy-functionalized ionogels (PFIG) with a high specific surface area, hydroxyl-rich groups and porous structure, which was formed by introducing highly hydrophilic [N4444][DEHP] into a silica gel substrate via the sol–gel method. The PFIG can take advantage of the beneficial properties of each component, including the nature of the solid carrier and the Li+ selective extraction ability of [N4444][DEHP]. The high extraction rate of Li+ up to 80.4 % was attained when the content of [N4444][DEHP] in the PFIG composite was 7 mL, which may be due to the strong chelation between [N4444][DEHP] and Li+ and the excellent hydrophilicity of the substrate to increase the mass transfer. Moreover, the competitive extraction experiments indicated that PFIG-7 had excellent high selectivity. Therefore, PFIG-7 has great potential application for lithium recovery from the mother liquor of Li2CO3.

Prospective oil palm (Elaeis sp) materials for high tocotrienol content

Crude palm oil (CPO) contains various forms of vitamin E, including tocopherol, tocotrienol and a small amount of tocomonoenol, collectively known as tocols. Among these, tocotrienol is dominant in CPO, constituting approximately 70% of the total tocols; unlike tocopherol, which is known for its anti-ageing properties, tocotrienol exhibits potent antioxidant activities, 60 times stronger than tocopherol. Tocotrienol is recognized for its diverse health benefits as a neuroprotective, nephroprotective, anti-cancer, anti-cholesterol, anti-diabetic, and anti-inflammatory agent. Consequently, tocotrienol holds immense potential for pharmaceutical and nutraceutical applications. The exploration of oil palm materials planted in Kebun Adolina PTPN IV, North Sumatera, has been conducted since 2020, encompassing diverse genetic backgrounds, including commercial palm DxP varieties, an interspecific hybrid of Elaeis oleifera x Elaeis guineensis, wild-type palm materials originated from Angola and Cameroon, and palm clones of commercial DxP varieties. The analysis revealed a wide range of total vitamin E (tocol) content, ranging from 310.78 ppm to 1681.45 ppm. Among the genotypes studied, AD14S311 and AD14S2220 emerged as promising candidates for ortets to develop oil palm varieties with high content, especially tocotrienol. These genotypes demonstrated a high oil extraction rate (OER) and a total vitamin E level above 1000 ppm. These findings remade the potential genotypes as genetic resources for breeding programs in developing oil palm varieties enriched with tocotrienol and fulfilled the commercial value.

Composite excipients for preparing concentrated water pills of personalized traditional Chinese medicine prescriptions by extruding-rounding method

This study aims to optimize the composite excipients suitable for the preparation of concentrated water pills of personalized traditional Chinese medicine prescriptions by the extruding-rounding method and investigate the roles of each excipient in the preparation process. The fiber materials and powder materials were taken as the standard materials suitable as excipients in the preparation of personalized concentrated water pills without excipient. Water absorption properties and torque rheology were used as indicators for selecting the materials of composite excipients. The ratio of composite excipients was optimized by D-optimal mixture design. Moreover, to demonstrate the universal applicability of the optimal composite excipients, this study selected three traditional Chinese medicine prescriptions with low, medium, and high extraction rates to verify the optimal ratio. Finally, the effects of each selected excipient on the molding of personalized concentrated water pills were investigated with the four parameters of the pill molding quality as indicators. The optimized composite excipients were dextrin∶microcrystalline cellulose(MCC)∶low-substituted hydroxypropyl cellulose(L-HPC) at a ratio of 1∶2∶4. The composite excipients were used for the preparation of personalized concentrated water pills with stable process, good quality, and a wide range of application. Dextrin acted as a diluent and accelerated the speed of extruding. MCC mainly served as an adhesive, increasing the cohesion and viscosity of the pills. L-HPC as a water absorbent and disintegrating agent can absorb and hold the water of the concentrate and has a strong disintegration effect.

Ultrasound-assisted Aqueous Two-Phase Extraction of Flavonoids from Scutellariae Radix and Evaluation of their Bioactivities In Vitro

Background: Scutellariae Radix, one of the most widely used herbs in Traditional Chinese Medicine, exhibits various biological activities due to its chemical components, which stand out for a number of flavonoids. In this study, Ultrasound-assisted aqueous two-phase extraction (UAATPE) was employed for the first time to obtain a high extraction rate and high purity of flavonoids from Scutellariae Radix. Methods: The Box-Behnken response surface method (RSM) was utilized to optimize the extraction conditions with the application of the new aqueous two-phase system (ATPS) composed of ethanol and ammonium sulfate. The major influence factors, including ethanol concentration, ammonium sulfate concentration, liquid-to-solid ratio, sonication time, and extraction temperature, were investigated by the single-factor experiment. The compositional characterization of flavonoids was characterized with HPLC-UV. Scanning electron microscopy (SEM) was applied to research the surface morphology of raw material. Furthermore, the bioactivities of the extract obtained by UA-ATPE were studied in vitro. Results: The optimal extraction conditions were as follows: the ethanol content was 26.12% (w/w), the ammonium sulfate content was 20.02% (w/w), the liquid-to-solid ratio was 40 mL/g, the sonication time was 5 min with the ultrasonic power of 250 W, and the operating process was performed at room temperature. Compared with the traditional extraction methods, UA-ATPE exhibited higher extraction efficiency and better extraction selectivity. The DPPH and ABTS radical scavenging tests showed that enriched products possessed strong antioxidant activity. Conclusion: The study confirmed that the developed method of UA-ATPE could be used as an efficient, eco-friendly, and low-consumption method for the extraction and purification of flavonoids from Scutellariae Radix.

Extraction and Separation of Natural Products from Microalgae and Other Natural Sources Using Liquefied Dimethyl Ether, a Green Solvent: A Review.

Microalgae are a sustainable source for the production of biofuels and bioactive compounds. This review discusses significant research on innovative extraction techniques using dimethyl ether (DME) as a green subcritical fluid. DME, which is characterized by its low boiling point and safety as an organic solvent, exhibits remarkable properties that enable high extraction rates of various active compounds, including lipids and bioactive compounds, from high-water-content microalgae without the need for drying. In this review, the superiority of liquefied DME extraction technology for microalgae over conventional methods is discussed in detail. In addition, we elucidate the extraction mechanism of this technology and address its safety for human health and the environment. This review also covers aspects related to extraction equipment, various applications of different extraction processes, and the estimation and trend analysis of the Hansen solubility parameters. In addition, we anticipate a promising trajectory for the expansion of this technology for the extraction of various resources.