Digestion Temperature Research Articles

Multivariate Optimization of a Green Microwave-Assisted Hydrogen Peroxide Digestion of Vegetable Oils and Subsequent Elemental Determination Via Inductively Coupled Plasma–Optical Emission Spectrometry

AbstractA microwave-assisted digestion technique based on dilute hydrogen peroxide (MW-AHPD) was developed for multielemental determination in vegetable oils. The determination of ten trace elements (As, Cd, Cr, Cu, Fe, Pb, Ni, Sn, V, and Zn) was conducted via inductively coupled plasma optical emission spectroscopy (ICP-OES) after digestion. The most influential parameters were investigated by using multivariate optimization tools (two-level full factorial and central composite design) with percent recovery as the chemometric response. The optimum conditions were 2.0 mol L−1 (H2O2]), 156 °C (digestion temperature), 0.1 g (sample mass) and 50 min (digestion time). Under the optimized conditions, the efficiency of digestion was evaluated based on the residual carbon content (RCC) of the final digests. The RCC values were very low, ranging from 0.84 to 1.60% (m/m). The greenness of the technique was evaluated using the Analytical Eco-scale, and the proposed method was considered an excellent green analysis method with a final score of 90. The accuracy of the optimized MW-AHPD was evaluated by spiking sunflower, olive, and peanut oils at concentrations of 2.5 and 5.0 μg L−1, and excellent recoveries between 90.3 and 107.3% were reported. The accuracy of the MW-AHPD method was compared with that of microwave-assisted digestion using concentrated HNO3, and there was no significant difference between the two methods. The limits of detection ranged from 0.026 to 14.6 μg L−1. On the other hand, the interday and intraday precisions were less than 6.67 and 6.96%, respectively. The method was successfully applied to determine the concentrations of trace elements in 5 vegetable oils on the South African market. Thus, MW-AHPD-ICP–OES is applicable for the determination of trace elements in vegetable oils.

Performance Monitoring of Greenhouse Biogas Digester

The country of South Africa is facing an energy crisis due to heavy reliance on fossil fuels, resulting in continuous load shedding. The use of renewable energy technologies can help resolve the current electricity crisis in the country. Moreover, waste-to-energy conversion has the potential to greatly contribute to economic development and improve public health. One such technology is biomass, which exploits waste-to-energy conversion. Additionally, solar energy can be utilized to maintain appropriate digester temperatures for optimal biogas yield. The study aims to assemble a portable balloon biogas digester in an enclosed greenhouse cavity and feed it with cow dung. Daily monitoring of pH and temperature (ambient, greenhouse, and slurry) was conducted, while biogas yield was monitored using a serial residential diaphragm flow meter. Furthermore, the composition of methane was monitored using the SAZQ biogas analyzer. The study investigated the impact of temperature on biogas production. The results revealed that the gas production rate of biogas fermentation increased within a certain temperature range. Therefore, maximum biogas production was achieved at a pH of 6.84 to 7.03, and the composition of methane exceeded 50%. Consequently, the study concluded by indicating that the digester housed within a greenhouse envelope, as demonstrated in this novel study, maintains the temperature within the optimal mesophilic range necessary for anaerobic digestion.

Multifunctional TiO2(R)/Fe2O3 Photocatalytic Composites Obtained from Ilmenite Ore

AbstractThe commercialization of the photocatalysis technology requires that the synthesis of the photocatalytic material is easy to scale up. Thus, the synthesis from earth‐abundant minerals represents one plausible solution to obtain materials by a scalable process with a lower environmental impact. So far, the most promising photocatalyst for this application is titanium dioxide (TiO2), which can be obtained from ilmenite ore; however, its synthesis usually implies toxic solvents and complicated reaction conditions. Thus, here is proposed an optimized method to extract higher amounts of TiO2 by a multivariable Plackett‐Burman design of experiments considering the mass of the ore precursor, the addition of phosphoric acid (H3PO4), the digestion temperature, the amount of base to adjust the pH, and the final thermal treatment. From this design, it was possible to minimize the heat treatment and the amount of base used to favor higher TiO2 (rutile) content with the presence of additional phases of iron oxides (Fe2O3) that act as co‐catalyst to enhance the photocatalytic activity. The photocatalytic activity of the TiO2/Fe2O3 composites obtained was investigated in four model reactions to obtain solar fuels (H2 evolution and CO2 reduction) and to remove endocrine water pollutants (bisphenol A and dyeing water), using visible and natural solar irradiation, respectively.

Biochemical methane potentials in co-digestion of whey, macroalgae and cattle sludge at different mixture rates

In this study, cattle sludge, algae and cheese whey were mixed at 3 different ratios and co- digested under laboratory conditions at 4 different digestion temperatures in order to determine biochemical methane potentials. In addition, for comparison purposes with mixtures, cattle sludge alone was subjected to biogas treatment. The experimental setup designed and manufactured for this purpose. The highest biochemical methane potential (BMP) was obtained in the Mixture-2 which contains 30% cattle sludge, 20% algae and 50% cheese whey with 0,345 Nm3 CH4/kgVS at 45 ºC temperature. As the ratio of cheese whey in the mixtures and digestion temperature increased, the biochemical methane potential also increased. BMP of cattle sludge was less than that of all mixtures.

Selective recovery of platinum from spent catalysts to fabricate platinum/amorphous manganese oxide/corrugated silica carrier for formaldehyde removal

The efficient recovery and reutilization of spent Pt catalysts have two huge challenges in the metallurgical and chemical industries. Herein, platinum was selectively retrieved from spent Pt/γ-Al2O3 catalysts by a microwave-assisted aqua regia digestion strategy, and the as-obtained platinum extract was utilized to prepare a novel Pt/amorphous MnOx/corrugated silica carrier (Pt/MnOx/CSC) catalyst for formaldehyde removal. To decrease consumption of toxic aqua regia, the γ-Al2O3 in the spent catalysts was converted to chemically stabile α-Al2O3 via high-temperature calcination. The high Pt leaching efficiency of 98.31% was achieved at a digestion temperature of 110oC and aqua regia concentration of 40vol%. However, the high leaching temperatures and aqua regia concentrations caused the part dissolution of α-Al2O3, and thus decreased the Pt leaching efficiency. The CSC in the Pt/MnOx/CSC catalysts served as a support, while both the Pt nanoparticles and amorphous MnOx microspheres acted as active catalysts. The synergistical effects between the Pt and amorphous MnOx endowed the composite catalysts with excellent catalytic activity, and the HCHO removal efficiency reached 100% even after five cycle tests. On the one hand, the nanostructured MnOx microspheres provided great surface areas and rich oxygen vacancies for heterogeneous catalysis. On the other hand, the Pt nanoparticles not only enhanced the low-temperature reducibilities of MnOx, but also decreased the apparent activation energies of HCHO catalytic oxidation. This work provided a new strategy for the selective recovery of platinum from spent catalysts and the reutilization of Pt-based catalysts for the HCHO thermal catalytic oxidation.

Accurate determination of high sulfur content in sulfide samples: an optimized ICP-OES method

Determination of high sulfur content in sulfide minerals is crucial for various applications, including geochemistry, mining, and environmental monitoring. While inductively coupled plasma optical emission spectrometry (ICP-OES) is the preferred method for sulfur analysis, conventional sample preparation techniques often fall short when dealing with high sulfur concentrations. This study investigated optimized digestion conditions for accurate sulfur determination in sulfide minerals using ICP-OES. We employed anti-corrosion acid digestion bombs, an aqua regia–hydrofluoric acid system, and a digestion temperature of 180 °C, achieving exceptional results. Certified reference material recoveries ranged from 99.9 to 100.5%, with relative standard deviations between 0.42 and 0.84%. These results demonstrate the high accuracy and precision of the method. The optimized digestion protocol presented in this study provides a robust and reliable approach for accurate sulfur analysis in sulfide minerals, particularly for high concentrations.

Optimization of Enzyme-Assisted Extraction of Rosemary Essential Oil Using Response Surface Methodology and Its Antioxidant Activity by Activating Nrf2 Signaling Pathway.

Rosemary essential oil (REO) is widely recognized as a food flavoring and traditional herb and possesses potential antioxidant activity. However, its low yield rate and unclarified antioxidant mechanism warrant further investigation. In this study, an enzyme pretreatment-assisted extraction method with Box-Behnken design (BBD) and response surface methodology (RSM) models was employed to optimize the main factors of REO, and its antioxidant molecular mechanism under oxidative stress was elucidated in hydrogen peroxide-induced human lung carcinoma (A549) cells. The optimized yield (4.10%) of REO was recorded with the following optimum conditions: enzyme amount 1.60%, enzyme digestion pH 5.0, enzyme digestion temperature 46.50 °C, and enzyme digestion time 1.7 h. Meanwhile, 1.8-cineole (53.48%) and β-pinene (20.23%) exhibited radical scavenging activity higher than that of BHA and BHT. At the cellular level, REO (12.5-50 µg/mL) increased the levels of cell viability, CAT, SOD, and GSH significantly while reducing the contents of ROS, MDA, and GSSG, when compared to H2O2 exposure. Mechanically, REO relieved oxidative stress via activating the Nrf2 signaling pathway and enhancing the protein expression of Nrf2, NQO-1, and HO-1, which was further verified by molecular docking between the main component 1.8-cineole and the Kelch domain of KEAP1. Therefore, REO could be considered as a potent natural antioxidant with a potential strategy in the food and pharmaceutical industries.

Accurate Boron Determination in Tourmaline by Inductively Coupled Plasma Mass Spectrometry: An Insight into the Boron-Mannitol Complex-Based Wet Acid Digestion Method.

Tourmaline, a boron-bearing mineral, has been extensively applied as a geothermometer, provenance indicator, and fluid-composition recorder in geological studies. In this paper, the decomposition capability of an HF-HNO3-mannitol mixture for a tourmaline sample was investigated in detail for the first time, and a wet acid digestion method based on the boron-mannitol complex for accurate boron determination in tourmaline by inductively coupled plasma mass spectrometry (ICP-MS) was proposed. With a digestion temperature of 140 °C, tourmaline samples of 25 mg (±0.5 mg) can be completely decomposed by a ternary mixture, which consisted of 0.6 mL of HF, 0.6 mL of HNO3, and 0.7 mL of 2% mannitol (wt.), via a continuous heating treatment of 36 h. Following gentle evaporation at 100 °C, the sample residues were re-dissolved using 2 mL of 40% HNO3 solution (wt.) and diluted to about 2.0 × 105-fold by a two-step method using 2% HNO3 solution (wt.). The boron contents in a batch of parallel tourmaline samples were then determined by ICP-MS, and results showed that the boron concentration levels were in a range of 3.20-3.44% with determination RSDs less than 4.0% (n = 5). It was found that the boron concentrations obtained at the mass of 10B were comparable with results from the measurements at the mass of 11B. This revealed that the usage of 2% mannitol with a quantity as high as 0.7 mL in this developed approach did not exhibit significant effect on the quantification accuracy of boron at the mass of 11B. It was also found that the processes including fluoride-forming prevention and fluoride decomposition deteriorated the boron-reserving efficiency of mannitol for tourmaline, causing the averaged boron contents to vary from 2.25% to 3.57% (n = 5). Furthermore, the stability of the boron-mannitol complex under 185 °C by applying the laboratory high pressure-closed digestion method was evaluated, which showed that there existed a 60.36% loss of boron compared to that under 140 °C by using this proposed approach. For this ternary mixture, the tourmaline decomposing efficiency was found to be weakened prominently using 100 °C as the digestion temperature, and tourmaline powders can be observed even after 72 h of continuous heating with B contents within 1.09-1.23% (n = 5). To assess the accuracy of this developed method, the boron recovery of anhydrous lithium tetraborate was studied. It was found that the boron recoveries were within 96.59-102.12% (RSD < 1%, n = 5), demonstrating the accuracy and reliability of this proposed method, which exhibits advantages of high B preserving efficiency, and giving concentration information of both B and trace elements simultaneously. By applying such a boron-mannitol complex-based wet acid digestion method, the chemical composition of boron and trace elements in three tourmaline samples from different pegmatites were quantified, which provided valuable information to distinguish regional deposits and the associated evolution stages.

An Optimized Microwave-Assisted Digestion Method to Analyze the Amino Acids Profile of Quisqualis Fructus from Different Planted Origins.

This study aims to establish a rapid and convenient microwave-assisted digestion method for sample pretreatment to determine amino acid profiles in natural products. This method was applied to analyze the amino acid profiles of Quisqualis Fructus (QF) from different planted origins. The microwave-assisted digestion conditions were optimized by a response surface methodology (RSM), and 17 amino acids in different planted origins of QF were determined by an automatic amino acid analyzer according to the optimized digestion conditions. The contents of 17 amino acids in QF from different planted origins were further analyzed by fingerprint and chemometric analysis. The temperature of microwave digestion at 167 °C, time of microwave digestion at 24 min, and a solid-liquid ratio of 46.5 g/mL was selected as the optimal digestion conditions. The total content of 17 amino acids in QF from different planted origins ranged from 71.88 to 91.03 mg/g. Amino acid composition and nutritional evaluation indicated that the content of medicinal amino acids was higher than aromatic amino acids. The results of fingerprint analysis reflected that the similarity between the 16 batches of QF ranged from 0.889 to 0.999, while chemometrics analysis indicated amino acid content in QF varied from different planted origins, and six important differential amino acids were screened. Compared with the traditional extraction method, microwave-assisted digestion with response surface optimized has the advantages of rapidity, convenience, and reliability, which could be used to study the amino acid profiles in natural products. The amino acid profile of QF indicated that it has a rich medicinal nutritional value. Different planted origins of QF have a high degree of similarity and could be effectively distinguished by chemometric analysis.

Influence of the Parameters of an Agricultural Biogas Plant on the Amount of Power Generated

Energy from biogas is widely available, inexpensive, and often contributes to waste management, making it one of the most promising renewable energy sources. The main factors influencing this process’ efficiency include the substrates’ chemical composition, temperature, and digester load. This paper presents the possibilities offered by a biogas plant built at a farm specialising in dairy cows. The dependence of the power generated in the micro biogas plant on its technical parameters was analysed in detail. Studies carried out by the authors in an agricultural microgas plant (with an electrical output of 40 kW) have shown that they are designed to maintain continuous energy production, despite changing process parameters such as digester mass level, biogas height, temperature or slurry flow into the digester. However, from the point of view of the amount of electricity generated, changes would have to be made to the design of the biogas plant. Firstly, a more powerful generator would have to be installed to cover the electricity requirements of the equipment installed in the biogas plant so that power close to the rated capacity of the biogas plant is still sent to the grid. Secondly, replacing the two existing agitators of the digestion mass (9 kW each) with more agitators of lower power (e.g., four agitators of 4.5 kW each) would be necessary. These should be programmed so that one of the agitators operates at any given time (the operating time of a given agitator should depend on the composition of the digestate).

Multiplex Detection of Seven Staphylococcal Enterotoxins Using Liquid Chromatography–Mass Spectrometry Combined with a Novel Capture Molecule

Food poisoning caused by Staphylococcal enterotoxins (SEs) is prevalent globally, making efficient detection of these toxins very important. Traditionally, liquid chromatography–mass spectrometry required immunosorbent enrichment by magnetic bead-coupled antibodies obtained by animal-specific immunization. However, this method is time-consuming and costly. In this study, two recombinant protein capture molecules were designed based on the principle of toxins binding to Major Histocompatibility Complex (MHCII) and T cell receptor (TCR) molecules. The two capture molecules are called MHCII and MHCII-D10. The design of the MHCII and TCR-D10 was achieved through searching for the binding site protein sequence of Staphylococcal enterotoxins in the relevant literature, and MHCII-D10 was to link MHCII sequence with TCR-D10 sequence using linker (G4S)3 linking peptide. These capture molecules were shown to effectively bind to seven types of toxins and to capture SEs in various matrices. The digestion time, ratio, and temperature were further optimized, reducing the overall digestion time to just 2 h. The specificity, linearity, sensitivity, precision (RSD%), and recovery of the two methods were verified by liquid chromatography–mass spectrometry. When the MHCII and MHCII-D10 captured the toxins, the limit of quantification (LOD) in the 1 × PBS, plasma, and milk matrices ranged from 1.5625 to 100 fmol/µL, with the recovery rate ranging from 18.4% to 96%. The design of these capture molecules eliminates the need for animal-specific immunization, simplifying the pre-detection process and avoiding ethical concerns. This development holds significant promise for clinical diagnosis and reference.

Aluminium Determination in Foodstuffs by ICP-MS: Influence of Microwave Digestion Parameters on the Recovery

Aluminium (Al) is the third most common element in the Earth’s crust and occurs naturally in drinking water and agricultural products, and humans are consequently exposed to the element from dietary sources. A tolerable weekly intake of 1 mg/kg has been established by the European Food Safety Authority (EFSA); however, no maximum levels for aluminium in foodstuffs have so far been established in the European Union (EU) legislation. Official food control requires validated methods for the determination of aluminium. Acid digestion assisted by microwaves is the main sample preparation technique used for the determination of aluminium, usually in combination with atomic spectrometry for quantification. In the present study, different parameters in the digestion step were investigated including test portion, digestion temperature, the reagent used and duration of the digestion to assess the aluminium extraction. The presented work is following up on an observation from a proficiency test (PT) on trace elements (including aluminium) in cocoa powder organised in 2020 by the European Union Reference Laboratory for metals and nitrogenous compounds in feed and food (EURL-MN), where the participant results for aluminium showed an unexpectedly large variation. In addition to the PT material, different certified reference materials were included in the present study, and the results highlighted that the temperature and reagent used are the most critical parameters to obtain a satisfactory sample digestion prior to aluminium determination. Based on the obtained results, it is recommended to digest food samples with a mix of ultrapure water and nitric acid for 25 min at a temperature of at least 240 °C with a mix of HNO3 and H2O to achieve satisfactory microwave-assisted digestion.

Isolation and Characterization of Microorganisms Involved in Biogas Production from Agricultural Waste

The study aimed to investigate the microbial composition involved in the biogas production process using a diverse range of substrates, including Spinacia oleracea (vegetable), banana peel, plant extract, watermelon residue, wheat straw and paddy straw, sourced from multiple locations in Jaunpur. Over a period of five weeks (30 days), the research employed established microbiological methodologies and customized anaerobic bio-digesters for the comprehensive analysis of the isolates and substrates to assess biogas generation. The evaluation revealed dynamic fluctuations in the digester temperature within the range of 30°C to 36°C, accompanied by initial pH levels ranging from 4.2 to 8.3, which subsequently decreased to pH 5-6 during and after the anaerobic digestion process. The identified anaerobic bacterial species encompassed Staphylococcus sp., Micrococcus, Enterobacter, Escherichia, Citrobacter, Bacillus sp., and Pseudomonas aeruginosa. Furthermore, the findings demonstrated a hierarchy in the percentage of biogas yield from the substrates, with the following ranking: synergistic mixture &gt; plant extract &gt; banana &gt; wheat straw &gt; spinach &gt; watermelon. Notable disparity in the volume of biogas produced was observed across different substrate treatments and digestion periods. The research underscored the pivotal role of methanogens and other auxiliary bacteria in the overall biogas production process. Additionally, the average pH levels were determined to range between 6.3 - 7.2 before and 5.0 - 6.2 during and after anaerobic digestion. The observed decline in pH during the anaerobic digestion process was associated with the production of metabolites such as acetate, hydrogen gas, carbon dioxide and other volatile fatty acids, exerting significant influence on the substrates within the digesters.

On the survival and habitat use of hatchery-reared cisco (Coregonus artedi) in Lake Erie

Cisco (Coregonus artedi) have been extirpated from Lake Erie in North America since the 1960s, but they once supported one of the largest Laurentian Great Lakes fisheries. Numerous potential impediments to rehabilitation have been identified, including summer habitat refugia and predation. We used acoustic telemetry to investigate the thermal habitat use and survival of hatchery-reared adult cisco in Lake Erie. Fish were experimentally released (n = 50 per site) offshore at Dunkirk, New York, in the eastern basin and Huron, Ohio, in the central basin. Cisco in both basins found suitable summer oxythermal habitat in the metalimnion, suggesting that coldwater habitat availability is likely not an impediment for reestablishment. However, track end dates or predation dates were distributed across only four months with the last detection at 155 days. Predation sensors combined with temperature values during digestion indicated different potential predators: lake trout (Salvelinus namaycush) for the Dunkirk group and walleye (Sander vitreus) for the Huron group. Additionally, digestion temperatures of two tags indicated bird predation was also important, likely underestimated and suggested substantial use of the epilimnion by tagged fish. The results highlight the need for additional studies to address stocking optimization questions in support of future reintroduction experiments and related cisco conservation efforts.

A hybrid approach of anaerobic digestion model no. 1 and machine learning to model and optimize continuous anaerobic digestion processes

Anaerobic digestion is a promising approach to dispose of biodegradable waste and wastewater, generating biogas as an alternative energy resource. This work proposed a so-called M-CADM1 for continuous anaerobic digestion simulation, which combined the machine learning and anaerobic digestion model No.1 (ADM1). The detailed reaction path and intermediate products in different stages of anaerobic digestion are specified in ADM1. The kinetic parameters were modified by machine learning. The characteristics (elemental composition) of feedstocks were used to predict kinetic parameters. A total of 75 biomass samples were used to establish for machine learning models. Five element contents (C, H, O, N, S), feedstock feed rate, and anaerobic digestion temperature were used as the input. The kinetic parameters were set as output. The sensitivities of 17 kinetic parameters were evaluated. 7 kinetic parameters with the highest sensitivities were selected as ADM1 model inputs by sensitivity analysis. The R2 and RMSE were used as the index to evaluated the accuracy of machine learning model. The best R2 and RMSE reached 0.84 and 0.196. The TIC was used as the index to evaluated the accuracy of M-CADM1. By comparing the simulated value with the experimental value, the accuracy of the overall M-CADM1 expressed by TIC of kitchen waste was 0.036. The organic acid content and pH in the reactor were considered as indicators to study the accuracy and stability of the M-CADM1. Trends in organic acids, free ammonia or hydrogen inhibition, and pH were consistent with experimental continuous anaerobic digestion results.

Comparative evaluation of Artificial intelligence based models and kinetic studies in the prediction of biogas from anaerobic digestion of MSW

The generation of biogas from the decomposition of MSW increases greenhouse gas emissions, contributing to global warming. However, the produced biogas can be effectively captured for conversion into a renewable energy resource. This study demonstrates the utility of artificial neural networks (ANN), adaptive network-fuzzy inference systems (ANFIS), and kinetic models in predicting biogas production from the anaerobic digestion of MSW. The digestion time, volatile solids, pH, temperature, and moisture content were selected as the independent variables. Furthermore, kinetic studies were conducted to predict the biogas yield using First-order, modified Gompertz, Logistic, and Transference models. To assess the efficacy of these models, their performance was evaluated using the coefficient of determination (R2) and root mean square error (RMSE). Upon comparing the results, it was evident that for set IX under 100 % field capacity (FC), the ANFIS network exhibited superior performance with RMSE and R2 values of 0.670 and 0.999, respectively. In comparison, the ANN and modified Gompertz models yielded RMSE values of 0.863 and 21.705, and R2 values of 0.999 and 0.998, respectively. While the coefficient of determination (R2 ≥ 0.99) suggested satisfactory agreement between all the models and experimental data, the ANFIS and ANN models achieved notably lower RMSE values, demonstrating their competitive performance.

Multi-criteria-based decision-making assessment for anaerobic digestion of ammonia-rich distillery wastewater: Effect of pyrochar and temperature

Energy-efficient wastewater treatment units are imperative to achieve carbon neutrality and a circular economy at the industrial scale. In the present study, pyrochar loading and digestion temperature were tested to assess their impact on the performance of an anaerobic digester running on distillery wastewater. The digestion temperature (37 °C and 55 °C) and pyrochar loading (7.5 – 30 g/L.feed) were selected as two primary design factors. Experiments were designed using Taguchi’s design of experiments and specific methane yield, total ammonia nitrogen, pH and buffering capacity were selected as experimental outputs for multi-criteria assessment. The results from the confirmation test indicated that the addition of pyrochar (7.5 g/Lfeed) improved the methane yield (276 ± 15 L/kg VS) significantly compared to the control (167 ± 15 L/kg VS) at 37 °C. The detailed post-digestion analysis showed that the adsorption of ammonia on pyrochar may be the primary reason for enhanced digester performance.

Cold dispase digestion of murine lungs improves recovery and culture of airway epithelial cells.

Airway epithelial cells (AECs) play a key role in maintaining lung homeostasis, epithelium regeneration and the initiation of pulmonary immune responses. To isolate and study murine AECs investigators have classically used short and hot (1h 37°C) digestion protocols. Here, we present a workflow for efficient AECs isolation and culture, utilizing long and cold (20h 4°C) dispase II digestion of murine lungs. This protocol yields a greater number of viable AECs compared to an established 1h 37°C dispase II digestion. Using a combination of flow cytometry and immunofluorescent microscopy, we demonstrate that compared to the established method, the cold digestion allows for recovery of a 3-fold higher number of CD45-CD31-EpCAM+ cells from murine lungs. Their viability is increased compared to established protocols, they can be isolated in larger numbers by magnetic-activated cell sorting (MACS), and they result in greater numbers of distal airway stem cell (DASC) KRT5+p63+ colonies in vitro. Our findings demonstrate that temperature and duration of murine lung enzymatic digestion have a considerable impact on AEC yield, viability, and ability to form colonies in vitro. We believe this workflow will be helpful for studying lung AECs and their role in the biology of lung.

Ultrasonic-ethanol pretreatment assisted aqueous enzymatic extraction of hemp seed oil with low Δ9-THC

In this study, ultrasonic-ethanol pretreatment combined with AEE was developed for oil extraction from hemp seeds. The oil yield reached a maximum of 23.32 % at 200 W ultrasonic power and 30 min ultrasonic time, at this point, the degradation rate of Δ9-THC was 83.11 %. By determining the composition of hemp seed before and after pretreatment, it was shown that ultrasonic-ethanol pretreatment reduced the protein content of the raw material. An enzyme mixture consisting of pectinase and hemicellulase (1/1/1, w/w/w) was experimentally determined to be used, and the AEE extraction conditions were optimized using the Plackett-Burman design and the Box-Behnken. The optimal conditions were determined to be pH 5, total enzyme activity of 37,800 U/g, liquid–solid ratio of 10.4 mL/g, enzyme digestion temperature of 32 °C, enzymatic time of 189 min, and oil recovery of 88.38 %. The results of confocal laser scanning microscopy (CLSM) and scanning electron microscopy (SEM) showed that the emulsion formed during ultrasonic ethanol pretreatment was not uniformly distributed, and the droplets appeared to be aggregated; and the irregular pores of hemp seed increased after pretreatment. The contents of Δ9-THC and CBN in the extracted oil samples were 9.58 mg/kg and 52.45 mg/kg, respectively. Compared with the oil extracted by Soxhlet extraction (SE), the oil extracted by this experimental method was of better quality and similar in fatty acid composition.

Simultaneous Determination of Mineral Nutrients and Toxic Metals in M. stenopetala from Southern Ethiopia: A Comparative Study of Three Cultivating Areas Using MP-AES.

In this study, for the first time, the levels of thirteen micro- and macromineral nutrients in the leaves, seeds, and supportive soil of Moringa stenopetala (M. stenopetala) were simultaneously determined using microwave plasma atomic emission spectroscopy (MP-AES). The samples were collected during the arid season, in 2019 from the three main M. stenopetala growing areas in southern Ethiopia (Chano Mile Kebele, Nechisar Kebele, and Konso Special Woreda). A novel digestion method for leaf and seed samples was developed using an optimized acid mixture (2.5 : 0.75 : 0.5 of HNO3, HClO4, and H2O2) at 240°C for 2 hrs and 30 min, resulting in clear and colorless solutions. The method makes the digestion process more efficient by minimizing the reagent volume, reducing digestion temperature and time, and simplifying the overall procedure. The efficiency of the optimized procedure was validated by spiking experiments, and the percentage recovery ranged between 94 and 110%. Under optimized experimental conditions, higher concentrations of essential minerals (K, Na, Ca, and Mg) were observed in the plant leaf and seed samples from the three areas. In addition, significant amounts of trace elements (Fe, Mn, Zn, and Cu) were also found. Importantly, no traces of the toxic elements (Cd and Pb) were detected in any of the analyzed samples, suggesting that the leaves and seeds of M. stenopetala are valuable sources of both micro- and macromineral nutrients and are safe from toxic metals. From a dietary perspective, the seed contains almost comparable concentrations of minerals as the leaves. As a result, the seeds of M. stenopetala can serve as an alternative source of minerals and play a role in overcoming the current global food crisis, particularly in the dry season. Analysis of variance at a 95% confidence level revealed significant differences in the levels of all mineral nutrients between the three sample means except K, Ca, Co, and Cu. Generally, the developed method includes an innovative digestion procedure that minimizes reagent consumption, operates at lower temperatures, and requires shorter digestion times, thereby optimizing resource utilization and maintaining analytical accuracy. Notably, the absence of toxic elements in the MP-AES procedure highlights the safety and reliability of M. stenopetala leaves and seeds as valuable, contamination-free sources of essential nutrients.