Batch Extraction Research Articles

Quality Evaluation of Pulsatilla Total Saponins Extracts Via Quantitative Analysis of Multi-Components by Single Marker Method Combined with Systematic Quantified Fingerprint Method

In this paper, the quality evaluation of the total saponins extracts of Pulsatilla was carried out by using the quantitative analysis of multi-components by single marker (QAMS) and the systematic quantified fingerprint method (SQFM). Firstly, the difference between QAMS and external standard method (ESM) was compared to explore the feasibility of the former. Then, HPLC method was applied to establish the fingerprints of 5 batches of total saponins extracts from Pulsatilla. The results indicated that there was no significant difference between the measurements of QAMS and ESM (t-test, P>0.05). Using Pulsatilla saponin D as the internal standard (IRS), Pulsatilla saponin A, Pulsatilla saponin F and Oleanolic acid 3-O-β-D-Pyranoglucosyl-(1→4)-β-D-Pyranoglucosyl-(1→3)-α-L-Pyridine rhamnosyl-(1→2)-α-L-Pyranosinearabinoside(B9 for short) can be quantified simultaneously. Finally, the fingerprints of 5 batches of the total saponin extract of Pulsatilla were evaluated by using SQFM and hierarchical clustering analysis (HCA). Although there were some differences, the evaluation results were objective, true and comprehensive. Therefore, this method can be used to evaluate the quality of Pulsatilla and other traditional Chinese medicine.

Graphene oxide-metal oxide nanocomposites for on-target enrichment and analysis of phosphorylated biomolecules.

The surface of matrix-assisted laser desorption/ionization mass spectrometry target is modified for improved signal strength and detection of analytes. The developed method includes on-target enrichment and detection of phosphopeptides/phospholipids using graphene oxide-lanthanide metal oxides (samarium, gadolinium, dysprosium, and erbium) nanocomposites. Enriched phosphopeptides are detected using material enhanced laser desorption/ionization mass spectrometry and phospholipids by laser desorption/ionization-mass spectrometry. Nanocomposites are prepared using graphene oxide with respective metal salts at high pH. They are characterized for nano-morphology, chemistry, porosity, composition, crystallinity, and thermal stability. Phosphopeptides enrichment protocol is developed and optimized for tryptic β-casein digest and that of phospholipids by phosphatidylcholine standard. Statistical analyses of phosphopeptides and phospholipids from milk show overlapping results for gadolinium, dysprosium, and erbium oxide nanocomposites. GO-Gd2 O3 has better enrichment efficiency and application as LDI material. Selectivity for GO-Dy2 O3 is 1:2500, for GO-Sm2 O3 is 1:3500, and 1:4000 for GO-Gd2 O3 . GO-Er2 O3 has a sensitivity of 25 fmol, whereas the highest sensitivity is down to 0.5 fmol for GO-Gd2 O3 . On-target enrichment is batch to batch reproducible with a standard deviation of<1, reduced time of enrichment to 10min, and ease of operation compared to solid-phase batch extraction. The developed method enriches serum phosphopeptides characteristic of cancer-related phosphoproteins.

Discovery of quality control ingredients in burdock root by combining anti-tumor effects and UHPLC-QqQ-MS/MS.

Burdock root is the root of Arctium lappa L., a plant of the Compositae family, which has the effects of dispersing wind and heat, detoxifying and reducing swelling. In order to better control the quality of burdock root, a screening study of quality control indicators was carried out. The current research combines biological activity evaluation with chemical analysis to screen and identify the biologically active compounds of burdock root as chemical components for the quality control of herbal medicine. The efficacy of 10 batches of ethanol extracts of burdock roots was evaluated by a tumor inhibition experiment in S180 tumor-bearing mice. The five main chemical components of these extracts were simultaneously quantitatively measured by ultra-high performance liquid chromatography combined with triple quadrupole mass spectrometry. Pearson correlation analysis was used to establish the relationship between these extracts' biological activity and chemical properties. The results showed that chlorogenic acid, caffeic acid and cynarin were positively correlated with the effect of inhibiting tumor growth, and further bioassays confirmed this conclusion. In conclusion, chlorogenic acid, caffeic acid and cynarin can be used as quality control markers for burdock root's antitumor effect.

Study of Extraction Kinetics of Total Polyphenols from Curry Leaves

Solid-liquid batch extraction of total polyphenol content from curry leaves (Murraya koenigii L.) was studied in this paper. The effect of different solvent concentrations and temperatures on total polyphenol content was investigated by performing batch experiments. The experimental studies showed that the kinetics of solid-liquid batch extraction was influenced by different solvent concentrations and temperatures. In solid-liquid batch extraction, more recovery of total polyphenols was obtained for 50% (v/v) aqueous methanol and at 333 K temperature. The total polyphenol obtained at optimum conditions was 79.34 mgGAE/L. Mathematical modelling is an important engineering tool used to study the kinetics of extraction as well as in the design of the extraction process to reduce time, energy, and chemical reagents. Peleg and Power law, the two mathematical models, were used to study the kinetics of the batch extraction process. The Peleg model showed the best fit to explain the kinetics of process with R2 &gt; 0.99. Further conventional extraction methods are compared with the novel extraction method.

Mechanistic model for the batch extraction of oil from avocado seeds available for biofuel production

ABSTRACT Broad assessment is being directed everywhere by the researchers on the world to identify the alternative sources for eco-friendly fuel. In the present investigation, biodiesel was integrated from the waste avocado seeds. Since the seed is a bio-squander that has the fundamental supplements and unsaturated fats, there is a need to use this waste and convert them into a valuable item. The biodiesel production process includes two-step processes. The first step is extraction of oil from the seed by using ethanol as a solvent. The viable extraction was obtained with the optimum conditions were found to be at 80°C, with the solvent to feed the proportion of 7:2, 3 hours of extraction time. Kinetic models were developed for the extraction processes with an R2 value of 0.959 and 0.989. The second step is producing biodiesel from the extracted oil by transesterification process. Operating conditions used for the trans-esterification reaction were observed to be 60°C, KOH to oil weight proportion of 1% and oil to methanol mole proportion 1:6. The biodiesel properties were estimated and contrasted and benchmarks which demonstrated that the biodiesel could be utilized as an elective vitality asset in diesel engines. This research work comprises two principle goals. Initially, a numerical model was obtained to anticipate the best states of extraction of lipids from a dried avocado seed. Second, utilizing the lipid separated from the seed, the biodiesel must be produced. GCMS examined the acquired biodiesel, and the diesel properties were investigated.

Protein mapping of peanut extract with capillary electrophoresis.

Protein separation can be achieved with different modes of capillary electrophoresis, such as with capillary gel electroporesis (CGE) or with capillary zone electrophoresis (CZE). CZE protein mapping of peanut extract was approached in four different ways, combining neutral-coated or multilayer-coated capillaries with pHs well over or under the isoelectric point range of the proteins of interest. At acidic pHs, the mobility ranges of the major peanut allergens Ara h1, Ara h2, Ara h3, and Ara h6 were identified. Although the pH is a major factor in CZE separation, buffers with different compositions but with the same pH and ionic strength showed significantly different resolutions. Different components of the electrolyte were studied in a multifactorial design of experiment. CE-SDS and CZE proved to be suitable for protein mapping and we were able to distinguish different batches of peanut extract and burned peanut extract.

Efficiency of dihydroxamic and trihydroxamic siderochelates to extract uranium and plutonium from contaminated soils

Actinide-based mineral phases occurring in contaminated soils can be solubilized by organic chelators excreted by plants, such as citrate. Herein, the efficiency of citrate towards U and Pu extraction is compared to that of siderophores, whose primary function is the acquisition of iron(III) as an essential nutrient and growth factor for many soil microorganisms. To that end, we selected desferrioxamine B (DFB) as an emblematic bacterial trishydroxamic siderophore and a synthetic analog, abbreviated (LCy,Pr)H2, of the tetradentate rhodotorulic acid (RA) produced by yeasts. Firstly, the uranyl speciation with both ligands was assessed in the pH range 2–11 by potentiometry and visible absorption spectrophotometry. Equilibrium constants and absorption spectra for three [UO2(DFB)Hh](h−1)+ (h = 1–3) and five [UO2(LCy,Pr)lHh](2+h−2l)+ (−1 ≤ h ≤ 1 for l = 1 and h = 0–1 for l = 2) solution complexes were determined at 25.0 °C and I = 0.1 M KNO3. Similar studies for the Fe3+/(LCy,Pr)2– system revealed the formation of five species having [Fe(LCy,Pr)]+, [Fe(LCy,Pr)OH], [Fe(LCy,Pr)(OH)2]–, [Fe(LCy,Pr)2H], and [Fe2(LCy,Pr)3] compositions. Then, the ability of DFB, (LCy,Pr)H2, and citrate to solubilize either U or Pu from pitchblende-rich soils (soils 1 and 2) or freshly plutonium-contaminated soils (LBS and PG) was evaluated by performing batch extraction tests. U was extracted significantly only by citrate after a day. After one week, the amount of U complexed by citrate only slightly exceeded that measured for the siderochelates, following the order citrate > (LCy,Pr)H2 ≥ DFB ≈ H2O, and were comparatively very low. Pu was also more efficiently extracted by citrate than by DFB after a day, but only by a factor of ~2–3 for the PG soil, while the Pu concentration in the supernatant after one week was approximately the same for both natural chelators. It remained nearly constant for DFB between the 1st and 7th day, but drastically decreased in the case of citrate, suggesting chemical decomposition in the latter case. For the Fe-rich soils 1 and 2, the efficiencies of the three chelators to solubilize Fe after a day were of the same order of magnitude, decreasing in the order DFB > citrate > (LCy,Pr)H2. However, after a week DFB had extracted ~1.5 times more Fe, whereas the amount extracted by the other chelators stayed constant. For the less Fe-rich LBS and PG soils contaminated by Pu, the amounts of extracted Fe were higher, especially after 7 days, and the DFB outperformed citrate by a factor of nearly 3. The higher capacity of the hexadentate DFB to extract Pu in the presence of Fe and its lower ability to mobilize U qualitatively agree with the respective complexation constant ratios, keeping in mind that both Pu-containing soils had a lower iron loading. Noticeably, (LCy,Pr)H2 has roughly the same capacity as DFB to solubilize U, but it mobilizes less Fe than the hexadentate siderophore. Similarly, citrate has the highest capacity to extract Pu, but the lowest to extract Fe. Therefore, compared to DFB, (LCy,Pr)H2 shows a better U/Fe extraction selectivity and citrate shows a better Pu/Fe selectivity.

Accelerating Cu and Cd removal in soil flushing assisted by regulating permeability with electrolytes

Soil flushing is one of the common in-situ remediation technologies, in which the permeability of the soil determines its feasibility. Batch extractions showed that deionized water extracted about 20% Cu and 30% Cd from a soil. Electrolytes of 100 mmol/l NaCl, 500 mmol/l NaCl, and 167 mmol/l CaCl2 promoted the extractions to about 60% and 90%, respectively, with higher concentration and valence of cations being more effective. Presence of 100 mmol/l EDTA as a chelant further enhanced the extractions to near completion. Extractions appeared to occur concurrently via ion exchange, complexation with Cl− and predominantly chelation with EDTA. Column leaching in dynamic setups with electrolyte solutions in the presence of EDTA showed similar Cu and Cd removal degrees to the batch extractions. The permeability of soils during leaching decreased by up to 80%, decelerating time-dependent Cu and Cd removal, due to soil swelling by Na+. Electrolytes in leaching solutions well defended the permeability of soil against its decrease to as low as 3.5%, maintaining Cu and Cd removal rates. Formulating flushing solution with EDTA and proper electrolytes have advantages of not only enhancing extraction degrees but accelerating heavy metal removal from soil by regulating the permeability, with the potential to be extended to soils with high clay contents and thus low natural permeability.

Batch and Column Extraction of Lead from Al-Doura Oil Refinery Soil

The aim of this research is to investigate the extraction of lead (Pb) from soil of Al-Doura oil refinery in Baghdad/Iraq. Ethylenediaminetetraacetic acid disodium salt (Na2EDTA) and Hydrochloric acid (HCl) solution were used as extractants. Soil washing method was practiced in two ways, batch extraction and column extraction experiments. A set of batch experiments were carried out at different conditions of extractant (Na2EDTA, HCl) concentration, contact time, pH and agitation speed. From the batch experiments, the maximum removal percentages of Pb that have been obtained were 70 % using Na2EDTA (0.1M) at pH 4 , agitation speed 200 and at equilibrium time 4 hours and 65 % using HCl (1M) at pH 1.08 , agitation speed 200 at equilibrium time 5 hours. &#x0D; Column experiments were conducted at different conditions of extractant (Na2EDTA, HCl) concentration, contact time and flow rate. The maximum removal percentages of Pb were 78% using Na2EDTA (0.1M) at pH 4 , flow rate 30 ml/hr and equilibrium time 8 hours and 75% using HCl (1M) at pH 1.08, flow rate 20 ml/hr and equilibrium time 10 hours. &#x0D; The column extraction proved that the extractant volume required to achieve high removal efficiency is less than that of the batch extraction, but requires a longer contact time.&#x0D; The experimental data of batch and column extraction were applied in four kinetic models; first order, parabolic diffusion, two constant and Elovich model to find best fit model for extraction system. For batch extraction, the parabolic diffusion and two-constant models gave the best correlation {coefficient of determination (R2)} with experimental data using HCl and Na2EDTA respectively. While for column extraction, Elovich model gave good correlation with experimental data.

Extraction of Chlorophylls and Carotenoids from Microalgae: COSMO‐SAC‐Assisted Solvent Screening

AbstractEfficient pigment extraction is a key factor influencing the economic feasibility of microalgal biorefineries. Ethanol, acetone, ethyl acetate, and hexane were evaluated for the batch extraction of chlorophyll a, chlorophyll b, and carotenoids from Chlorella sorokiniana and Heterochlorella luteoviridis. Solvent‐to‐biomass ratios did not affect extraction results in most cases. Ethanol showed the highest efficiency in the recovery of chlorophylls, presenting high extraction yields. Acetone was among the most efficient solvents to extract violaxanthin, lutein, zeaxanthin, and carotene from both microalgae, proving to be generally suitable to this application. Conductor‐like screening model for real solvent segment activity (COSMO‐SAC) corroborated experimental results, proving to be an important tool in the screening of solvents for extraction processes.

Recovery and antioxidant activity of phenolic compounds extracted from walnut press-cake using various methods and conditions

Walnut (Juglans regia L.) press-cake is a residue of oil processing from which the phenolic compounds were extracted using ethanol 60 % by batch and semi-continuous operations, or by ultrasound-assisted maceration in the case of de-oiled cake, with particular attention to the variables time and solid-solvent ratio. For batch extraction, the conditions maximizing total phenolic yield (TPC) and radical scavenging activity evaluated by 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay were 60 °C without the addition of phospholipids, provided however for phenolic yield, that an extraction time of 60 min and a ratio of 25 mL of solvent per g of cake were applied. Values of up to 14.8 mg gallic acid equivalent (GAE)/gcake and 136.9 μmol Trolox equivalent/gcake were obtained. The semi-continuous variant gave a TPC of 19.8 mg GAE/gcake and an overall extract containing 8% phenolic compounds and 46 % oil. After de-oiling, the cake was subjected to ultrasound-assisted extraction. The TPC and DPPH varied slightly with the applied conditions, between 10.4 and 13.3 mg GAE/gcake and 83–107 μmol Trolox Equiv./gcake respectively, unless the solid/solvent ratio increased to 1/200 (TPC of 29 mg GAE/gcake). It was also shown that the oxidative stability of Camelina sativa L. Crantz oil increased from 24 to 72 h by enrichment with walnut extract.

Heat transfer evaluation for conventional and extractive ethanol fermentations: Saving cooling water

Ethanol production in Brazil has two major drawbacks, related to the maximum product concentration and control of the process temperature. During the fermentation, yeast metabolism completely ceases when the ethanol concentration reaches 95 g.L−1, while high temperatures increase both the risk of bacterial contamination and the sensitivity of the yeast to ethanol toxicity. In order to address these problems, extractive ethanol fermentation with carbon dioxide stripping offers a way to overcome the toxic effect of ethanol on yeast cell growth, while also avoiding increase of the broth temperature during the fermentation. Although ethanol removal by gas stripping has a positive effect on ethanol volumetric productivity, the application of this technique for economization of cooling water during the ethanol fermentation process requires a technical analysis. Therefore, in the present work, evaluation was made of heat removal from the culture broth during extractive fermentation with ethanol stripping by CO2. First, ethanol fermentations were carried out using a 10-L bench-scale bubble column bioreactor. The mass and energy balances were used to obtain kinetic parameters, with the heat generated during fermentation being close to theoretical values. Extractive batch fermentations were performed using two carbon dioxide specific flow rates (0.5 and 1.0 vvm), resulting in efficient removal of heat from the fermentation broth, as well as reducing cooling water consumption by up to 62.7%. These results were then validated in a pilot-scale (100-L) extractive fed-batch fermentation performed at 1.0 vvm, resulting in a 63.1% reduction of cooling water consumption. In an industrial distillery, this lower consumption of cooling water would allow substantial savings of chemicals needed for cooling water treatment, making the ethanol production process in Brazil more competitive in the near future.

Enhanced removal of uranium (VI) from leach liquors by aniline - polyaniline with Chinese D263B resin

ABSTRACT Aniline and polyaniline was successfully impregnated with Chinese D263B resin and polymerisation prepared via using polyvinyl alcohol as a surfactant and benzoyl peroxide to form impregnated D263B/aniline and D263B/polyaniline were used for enhancing the removal of U(VI) from Abu El Toyour leach liquor. The impregnated D263B/polyaniline was characterised by Fourier transform infrared spectroscopy (FT-IR) and scanning electron microscope (SEM). Experimental measurements have been optimised by batch extraction technique such as pH, contact time, initial U(VI) concentration, resin dosage, temperature and eluting agents. It was found that the maximum uptake capacity of Chinese D263B resin is 40 mg/g at room temperature, Chinese D263B resin with aniline is 86.95 mg/g and Chinese D263B resin with polyaniline is 121.95 mg/g. The resulted equilibrium data fitted well with Langmuir isotherm model. From kinetic parameters, it was found that U(VI) adsorption followed the pseudo-second order kinetic model. The thermodynamic parameters ΔH, ΔS and ΔG were also evaluated indicating exothermic, randomness and non-spontaneous adsorption process. U(VI) can be eluted approximately 99% from the loaded D263B/polyaniline using 1 M (1:1) NaCl/H2SO4. Finally, the optimised factors have been applied for enhanced U(VI) removal from Abu El Toyour leach liquor.

Optimization of batch extraction of functional ingredients from stevia leaves with response surface methodology

The aim of the study was to reveal an effective extraction procedure for maximization of the yield of stevioside, flavonoid, and total phenolic compounds as well as antioxidant activity in stevia extract. Extraction was carried out at temperature variations of 75 ÂΩC, 80 ÂΩC, 90 ÂΩC and variations of water solvents 280 mL/g, 290 mL/g, 300 mL/g. Stevioside and flavonoid analysis used spectrophotometer method, while phenol analysis used the Folin-Cioccalteau reagent method. The result is a change in temperature and solvent ratio affect the changes in stevioside, flavonoid, and phenol levels. Optimal conditions of stevioside, flavonoid, and phenol using response surface methodology (RSM) occur at a temperature range of 75 ÂΩC with a solvent ratio of 280-290 mL/g.

Substituent Effect on the Selective Separation and Complexation of Trivalent Americium and Lanthanides by N,O-Hybrid 2,9-Diamide-1,10-phenanthroline Ligands in Ionic Liquid.

The extraction and complexation of trivalent americium (Am) and lanthanides (Ln) by four 2,9-diamide-1,10-phenanthroline (DAPhen) ligands with different alkyl substituent groups on the diamide moiety in an ionic liquid (IL), C4mimNTf2, were studied through a combination of batch extraction, spectroscopic, and calorimetric approaches. All four DAPhen ligands can achieve selective separation of Am(III) from Eu(III), but the detailed extractability and the extraction kinetics are affected significantly by the length of the alkyl substituent groups. UV-vis absorption spectrophotometric titrations indicate that Ln(III) coordinates with all four ligands in a 1:2 mode in the ionic liquid and the binding strength decreases with the increase of the alkyl chain length. The complexation of the DAPhen ligands with Ln(III) in the ionic liquid is driven by highly positive entropies and opposed by endothermic enthalpies. A luminescence spectroscopy study suggests that each DAPhen ligand coordinates in a tetradentate form with Eu(III). This work further unravels the unique extraction and coordination behavior in an ionic liquid system and offers additional guidelines to design more efficient DAPhen ligands for Ln(III)/An(III) separation.

Intensified extraction and separation of zinc from cadmium and manganese by a slug flow capillary microreactor

Selective extraction of zinc from sulphate effluents containing zinc, cadmium and manganese by liquid–liquid extraction with a capillary microreactor operating in the slug flow regime was elaborately investigated. Experiments were carried out at a flow rate ratio 1:1 of aqueous to organic phase, with a set-up consisting of a T-mixer connected to a PTFE capillary microreactor, and a subsequent membrane separator. The influences of extractant saponification degree, initial aqueous pH, residence time and mixture velocity on separation performance were studied, which indicated that separation enhancement of zinc from cadmium and manganese can be achieved by controlling the residence time and mixture velocity in the capillary microreactor without any aqueous pH adjustment. The βZn/Cd 2232.86 and βZn/Mn 1288.90 could be accomplished within 45 s in microfluidic extraction, whereas only 233.39 and 193.05 within 25 min in batch extraction, confirming the significant separation enhancement. Furthermore, the overall volumetric mass transfer coefficient kLa and overall mass transfer coefficient kL were also determined, high kLa of zinc (0.055 s−1–0.472 s−1) and low kLa of cadmium (0.009 s−1–0.076 s−1) and manganese (0.011 s−1–0.083 s−1) were responsible for the significant separation performance in the slug flow microfluidic system.

Integrating metabolomic data with machine learning approach for discovery of Q-markers from Jinqi Jiangtang preparation against type 2 diabetes

BackgroundJinqi Jiangtang (JQJT) has been widely used in clinical practice to prevent and treat type 2 diabetes. However, little research has been done to identify and classify its quality markers (Q-markers) associated with anti-diabetes bioactivity. In this study, a strategy combining mass spectrometry-based untargeted metabolomics with backpropagation artificial neural network (BP-ANN)-based machine learning approach was proposed to screen Q-markers from JQJT preparation.MethodsThis strategy mainly involved chemical profiling of herbal medicines, statistic processing of metabolomic datasets, detection of different anti-diabetes activities and establishment of BP-ANN model. The chemical features of seventy-eight batches of JQJT extracts were first profiled by using the untargeted UPLC-LTQ-Orbitrap metabolomic approach. The chemical features obtained which were associated with different anti-diabetes activities based on three modes of action were normalized, ranked, and then pre-selected by using ReliefF feature selection. BP-ANN model was then established and optimized to screen Q-markers based on mean impact value (MIV).ResultsOptimized BP-ANN architecture was established with high accuracy of R > 0.9983 and relative low error of MSE < 0.0014, which showed better performance than that of partial least square (PLS) model (R2 < 0.5). Meanwhile, the BP-ANN model was subsequently applied to further screen potential bioactive components from the pre-selected chemical features by calculating their MIVs. With this machine learning model, 10 potential Q-markers with bioactivity were discovered from JQJT. The tested anti-diabetes bioactivities of 78 batches of JQJT could be accurately predicted.ConclusionsThis proposed artificial intelligence approach is desirable for quick and easy identification of Q-markers with bioactivity from JQJT preparation.

Selective Extraction of Medium-Chain Carboxylic Acids by Electrodialysis and Phase Separation.

Carboxylic acids obtained via the microbial electrochemical conversion of waste gases containing carbon dioxide (i.e., microbial electrosynthesis) can be used in lieu of nonrenewable building-block chemicals in the manufacture of a variety of products. When targeting valuable medium-chain carboxylic acids such as caproic acid, electricity-driven fermentations can be limited by the accumulation of fermentation products in the culturing media, often resulting in low volumetric productivities and titers due to direct toxicity or inhibition of the biocatalyst. In this study, we tested the effectiveness of a simple electrodialysis system in upconcentrating carboxylic acids from a model solution mimicking the effluent of a microbial electrochemical system producing short- and medium-chain carboxylic acids. Under batch extraction conditions, the electrodialysis scheme enabled the recovery of 60% (mol mol–1) of the total carboxylic acids present in the model fermentation broth. The particular arrangement of conventional monopolar ion exchange membranes and hydraulic recirculation loops allowed the progressive acidification of the extraction solution, enabling phase separation of caproic acid as an immiscible oil with 76% purity.

Addition of Grape Skin and Stems Extracts in Wines during the Storage to Reduce the Sulfur Dioxide: Impact on Red Wine Quality.

This study aimed to evaluate the usefulness of bioactive extracts obtained from red wine by-products, such as grape skins and stems, for reducing or eliminating the use of SO2 in red wine production. Special attention was focused on guaranteeing the microbiological stability of the red wines and protecting them against oxidation. Therefore, the antioxidant and antimicrobial activities of the extracts and red wines were studied. Red grape stems and skins, by-products of the wine industry, from six types of monovarietal wines, were used. Extracts obtained from stems displayed higher concentrations of total phenolic compounds and higher in vitro antioxidant activity. Both stem and skin extracts demonstrated higher antimicrobial activity against pathogenic bacteria and lower activity against yeasts. In the wines produced, higher antimicrobial and antioxidant activities were observed, mainly in the skin extract batches. This study highlights that bioactive extracts obtained from by-products of wine making could be used to reduce or eliminate the use of SO2 in wine production. In this way, healthier red wines could be obtained while guaranteeing their microbiological stability and protecting them from oxidation. Furthermore, the use of these by-products is strongly associated with the circular economy, as they could help to reduce the environmental impact of the wine industry.

Hydrothermal Synthesis of Fluorescent Schiff Base Functionalized Carbon Dot Composite for The Removal Of Cd(II) Ions From Aqueous Solution: Equilibrium and Kinetic Studies.

In this study, bis(salicylidene)ethylenediamine (SALEN) functionalized carbon dot derived from waste banana peels was synthesized using facile hydrothermal technique and the optical biomarker and adsorption properties of the highly fluorescent red nanomaterial studied. The carbon dot and its functionalized counterpart were characterized using FTIR, SEM/EDX and UV-Visible technique. Evaluation of the optical properties of the yellowish brown carbon dot and reddish highly luminescent functionalized carbon dot indicated band gap energy values of 1.85 and 2.04 eV respectively. Extraneous variables such as effect of initial metal ion concentration, pH and contact time were studied in the batch extraction process for the sorption of Cd(II) ions from aqueous solution. The sorption of Cd(II) ion was observed to be highest at pH 5 with 99.3 % removal efficiency. The adsorption isotherm and kinetic models indicated interplay of physisorption and chemisorption processes. The mechanism for the chelation of Cd(II) ions onto the surface of the functionalized carbon dot was mainly governed by inner aphere chelation and ion exchange. Reusability of the material was evaluated using adsorption-desorption experiments. Result of the study indicated the potential of the functionalized carbon dot as (i) semiconductor materials with strong photoluminescence at the visible region which could be used as environmental biomarker and as sensor (ii) effective, efficient and low cost adsorbent for remediating Cd(II) ions contaminated environment.