RESUMO
Peanut shells' adsorption performance in caffeine and triclosan removal was studied. Peanut shells were analyzed for their chemical composition, morphology, and surface functional groups. Batch adsorption and fixed-bed column experiments were carried out with solutions containing 30 mg/L of caffeine and triclosan. The parameters examined included peanut shell particle size (120-150, 300-600, and 800-2000 µm), adsorbent dose (0.02-60 g/L), contact time (up to 180 min), bed height (4-8 cm), and hydraulic loading rate (2.0 and 4.0 m3/m2-day). After determining the optimal adsorption conditions, kinetics, isotherm, and breakthrough curve models were applied to analyze the experimental data. Peanut shells showed an irregular surface and consisted mainly of polysaccharides (around 70% lignin, cellulose, and hemicellulose), with a specific surface area of 1.7 m2/g and a pore volume of 0.005 cm3/g. The highest removal efficiencies for caffeine (85.6 ± 1.4%) and triclosan (89.3 ± 1.5%) were achieved using the smallest particles and 10.0 and 0.1 g/L doses over 180 and 45 min, respectively. Triclosan showed easier removal compared to caffeine due to its higher lipophilic character. The pseudo-second-order kinetics model provided the best fit with the experimental data, suggesting a chemisorption process between caffeine/triclosan and the adsorbent. Equilibrium data were well-described by the Sips model, with maximum adsorption capacities of 3.3 mg/g and 289.3 mg/g for caffeine and triclosan, respectively. In fixed-bed column adsorption tests, particle size significantly influenced efficiency and hydraulic behavior, with 120-150 µm particles exhibiting the highest adsorption capacity for caffeine (0.72 mg/g) and triclosan (143.44 mg/g), albeit with clogging issues. The experimental data also showed good agreement with the Bohart-Adams, Thomas, and Yoon-Nelson models. Therefore, the findings of this study highlight not only the effective capability of peanut shells to remove caffeine and triclosan but also their versatility as a promising option for water treatment and sanitation applications in different contexts.
Assuntos
Arachis , Cafeína , Triclosan , Cafeína/química , Cafeína/isolamento & purificação , Triclosan/química , Triclosan/isolamento & purificação , Arachis/química , Adsorção , Cinética , Poluentes Químicos da Água/química , Poluentes Químicos da Água/isolamento & purificação , Tamanho da Partícula , Purificação da Água/métodosRESUMO
The extraction of valuable compounds from dried fruits and vegetables by microwave hydrodiffusion and gravity (MHG) requires previous hydration of the plant material. In this work, ultrasound was used to speed up the hydration of guarana powder before MHG extraction and increase caffeine recovery. The humidification step was speeded up with ultrasound taking only 15 min over 60 min without ultrasound. Water and 50% (v/v) ethanol were evaluated as green solvents for humidification, with a higher concentration of caffeine obtained for the hydroalcoholic solution. Ultrasound pretreatment allowed guarana extracts from MHG with two times more caffeine for both solvents evaluated. Therefore, ultrasound can be used in the hydration step before MHG extraction to reduce time and increase caffeine recovery from guarana powder.
Assuntos
Cafeína , Micro-Ondas , Paullinia , Extratos Vegetais , Pós , Cafeína/análise , Cafeína/isolamento & purificação , Paullinia/química , Extratos Vegetais/química , Gravitação , Ultrassom , SolventesRESUMO
A factorial design with a duplicate in the central point was used to investigate the effect of treating arabica coffee beans with asparaginase. The investigated factors were enzymatic load (1000 and 5000 ASNU/Kg), water percentage (30 and 90%), and hydrolysis time (1 and 3 h). The acrylamide content was determined by UPLC-MS/MS, and the caffeic acid, chlorogenic acid and caffeine concentrations were determined by HPLC-DAD. The statistical analysis was carried out in the R platform using RStudio graphical interface. The results indicated the importance of coffee bean pretreatment with steam, and that the enzyme load reduced the acrylamide content to 65 mg/kg in coffee beans. The predicted reduction was obtained with hydrolysis time of 2 h, water content of 90%, and asparaginase load of 5000 ASNU/kg. The asparaginase treatment did not influence the major bioactive compounds in coffee.
Assuntos
Acrilamida/análise , Asparaginase/metabolismo , Ácidos Cafeicos/análise , Cafeína/análise , Ácido Clorogênico/análise , Café/metabolismo , Ácidos Cafeicos/isolamento & purificação , Cafeína/isolamento & purificação , Ácido Clorogênico/isolamento & purificação , Cromatografia Líquida de Alta Pressão , Café/química , Hidrólise , Extração em Fase Sólida , Espectrometria de Massas em TandemRESUMO
Polypyrrole (PPy) was electrochemically synthesized with charge control on the surface of a steel mesh. Two different morphologies (globular and nanotubular) were created and characterized by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The modified electrodes were used as extraction phases in solid-phase extraction (SPE) and electrochemically controlled solid-phase extraction (EC-SPE) of atrazine, caffeine and progesterone. Raman spectroscopy was employed for the structural characterization of PPy after long exposure to the analytes. The electrochemical behavior was studied by cyclic voltammetry which revealed the higher capacitive behavior of polypyrrole nanotubes because of the huge superficial area, also no electrocatalytical behavior was observed evidencing the strong adsorption of the analytes on the PPy surface. The effects of the PPy oxidation state on the extraction performance were evaluated by in-situ electrochemical sorption experiments. The sorption capacity was evaluated by gas chromatography coupled to mass spectrometry (GC-MS). The method displays good stability, repeatability and reproducibility. The limits of detection range between 1.7-16.7 µg L-1. Following the extraction of river water samples, it was possible to identify the presence of other endogenous organic compounds besides the analytes of interest. This indicates the potential of the method and material developed in this work. Graphical abstract Schematic representation of a steel mesh electrode covered with polypyrrole nanotubes used as extraction phase for separation of contaminants from aqueous samples. The oxidation level of polypyrrole was electrochemically tuned by which the adsorption of analytes is deeply affected.
Assuntos
Atrazina/isolamento & purificação , Cafeína/isolamento & purificação , Nanotubos/química , Polímeros/química , Progesterona/isolamento & purificação , Pirróis/química , Extração em Fase Sólida/métodos , Adsorção , Técnicas Biossensoriais/métodos , Técnicas Eletroquímicas/métodos , Cromatografia Gasosa-Espectrometria de Massas , Limite de Detecção , Reprodutibilidade dos TestesRESUMO
In this study, a simple, efficient, and reusable device based on cellulose membranes modified with polypyrrole was developed to extract 14 emerging contaminants from aqueous matrices. For chemical polymerization, a low-cost cellulose membrane was immersed in 0.1 mol/L pyrrole and 0.5 mol/L ammonium persulfate for 40 min in an ice/water bath. The cellulose membranes modified with polypyrrole were accommodated in a polycarbonate holder suitable for solid-phase extraction disks. Solid-phase extraction parameters that affect extraction efficiency, such as sample volume, pH, flow rate, and desorption were optimized. Subsequently, determination of target compounds was performed by gas chromatography with mass spectrometry. The linear range for analytes ranged from 0.05 to 500 µg/L, with coefficients of determination above 0.990. The limits of quantification varied between 0.05 and 10 µg/L, with relative standard deviations lower than 17%. The performance of the proposed cellulose membranes modified with polypyrrole device for real samples was evaluated after extraction of emerging contaminants from a river water sample from the city of Curitiba, Brazil. Bisphenol A (6.39 µg/L), caffeine (17.83 µg/L), and paracetamol (19.28 µg/L) were found in these samples.
Assuntos
Celulose/química , Cromatografia Gasosa-Espectrometria de Massas/métodos , Extração em Fase Sólida/métodos , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/isolamento & purificação , Acetaminofen/análise , Acetaminofen/isolamento & purificação , Compostos Benzidrílicos/análise , Compostos Benzidrílicos/isolamento & purificação , Brasil , Cafeína/análise , Cafeína/isolamento & purificação , Fenóis/análise , Fenóis/isolamento & purificação , Polímeros/química , Pirróis/química , Rios/química , Extração em Fase Sólida/instrumentaçãoRESUMO
INTRODUCTION: The prevailing treatment for Alzheimer's disease is the use of acetylcholinesterase (AChE) inhibitors. Natural extracts are the principal source of AChE's inhibitors. However, their chemical complexity demands for simple, selective and rapid assays. OBJECTIVE: To develop a strategy for identification of AChE inhibitors present in mixtures employing high resolution mass spectrometry (HRMS) and thin layer chromatography (TLC)-biological staining. METHODOLOGY: The strategy uses an autographic assay based on the α-naphthyl acetate - fast blue B system for the detection of AChE activity. The immobilisation of AChE in agar allowed the extraction of the compounds for analysis by HRMS. Three TLC experiments employing different solvent systems were used in parallel and the mass spectra of the compounds extracted from the inhibition halos, were compared. The analysis was performed under MatLab environment. RESULTS: The strategy was used to detect the presence of physostigmine in an extract of Brassica rapa L. spiked with the inhibitor. Similarly, caffeine was straightforwardly spotted as responsible for the inhibitory properties of an extract of Ilex paraguariensis Saint-Hilaire. Comparison of the HRMS profiles lead to the facile identification of the [M+H](+) and [M+Na](+) of the compounds responsible for the inhibition. CONCLUSION: The proposed methodology, coupling TLC-AChE autography-HRMS, illustrates the feasibility of assigning molecular formulas of active compounds present in complex mixtures directly from autography. The new AChE agar-immobilised assay presented a more homogenous colour and a better definition than direct spraying methods, reducing the cost of the assay and improving its sensitivity.
Assuntos
Autorradiografia/métodos , Produtos Biológicos/química , Inibidores da Colinesterase/análise , Cromatografia em Camada Fina/métodos , Ilex paraguariensis/química , Espectrometria de Massas/métodos , Autorradiografia/economia , Brassica rapa/química , Cafeína/isolamento & purificação , Cromatografia em Camada Fina/economia , Descoberta de Drogas , Espectrometria de Massas/economia , Fisostigmina/análiseRESUMO
This study aimed to assess the capacity of saponite modified with n-hexadecyltrimethylammonium bromide (CTAB) and/or 3-aminopropyltriethoxysilane (APTS) to adsorb and remove caffeine from aqueous solutions. Powder X-ray diffraction (PXRD) revealed increased basal spacing in the modified saponites. Small-angle X-ray scattering (SAXS) confirmed the PXRD results; it also showed how the different clay layers were stacked and provided information on the swelling of natural saponite and of the saponites functionalized with CTAB and/or APTS. Thermal analyses, infrared spectroscopy, scanning electron microscopy, element chemical analysis, and textural analyses confirmed functionalization of the natural saponite. The maximum adsorption capacity at equilibrium was 80.54 mg/g, indicating that the saponite modified with 3-aminopropyltriethoxysilane constitutes an efficient and suitable caffeine adsorbent.
Assuntos
Silicatos de Alumínio/química , Cafeína/isolamento & purificação , Compostos Orgânicos/química , Purificação da Água/métodos , Difração de Raios X/métodos , Adsorção , Cafeína/química , Nanopartículas/química , Nanopartículas/ultraestrutura , Tamanho da Partícula , Espalhamento a Baixo Ângulo , Poluentes Químicos da Água/isolamento & purificaçãoRESUMO
A novel and fast method based on the solid phase extraction (SPE) coupled to a flow injection system for the determination of caffeine in coffee beans was developed. The caffeine extraction of coffee beans was carried out with hot water. A C18 reverse-phase mini-column was coupled to a continuous flow manifold to carry out the on-line SPE and the quantification of caffeine from aqueous extracts. Column length, retention time, elution volume, extracting solution and injection volume were evaluated. The retention time was of 90s and the elution was carried out with 400 µL of a methanol:water mixture (25:75). The proposed on-line SPE was compared against a chloroform extraction from aqueous extracts. With the proposed method the sample preparation was minimised and the sample throughput was increased (10 determination/h) because no dilution was required. Green coffee beans and beans with different roasting degree were analyzed.
Assuntos
Cafeína/análise , Cafeína/isolamento & purificação , Coffea/química , Análise de Injeção de Fluxo/métodos , Sementes/química , Extração em Fase Sólida/métodos , Automação , Cromatografia Líquida de Alta Pressão/métodos , Culinária , Análise de Injeção de Fluxo/instrumentaçãoRESUMO
ETHNOPHARMACOLOGICAL RELEVANCE: Guarana (Paullinia cupana Kunth var. sorbilis (Mart.) Ducke) has been traditionally consumed by indigenous communities of the Amazon region. It is valued mainly for its stimulant property because of its high content of caffeine, which can be up to 6% in the seeds. AIM OF THE REVIEW: The purpose of this review is to revisit this typically Brazilian plant, addressing economic considerations, the chemical makeup of the seeds and pharmacological properties so far investigated. RESULTS: Guarana is primarily produced in the Brazilian states of Amazonas and Bahia, and approximately 70% of the production is used by the industry of soft and energy drinks. The other 30% becomes guarana powder for direct consumption in capsules or dilution in water, or it serves as a raw material for the pharmaceutical and cosmetics industries. In addition to its stimulant property, guarana has other therapeutic properties, which have aroused the interest of the scientific community. CONCLUSION: This review shows that other guarana properties may be explored and how scarce are the studies regarding agronomic, plant pathology, physiology and breeding. So far, caffeine has been the main reason to study guarana and still will lead the researches because the demand for this alkaloid by food and pharmaceutical industry, and a strongly growing market related with beauty products. However, guarana has other components and there is great interest in studies designed to elucidate the effects of guarana's bioactive components and their potential pharmacological applications. Significant part of the guarana production in Brazil still comes from Indians tribes in the Amazon State, and any improvement in this plant, in any aspect, may propitiate a positive economic impact in their lives.
Assuntos
Paullinia , Extratos Vegetais/farmacologia , Animais , Brasil , Cafeína/isolamento & purificação , Humanos , Sementes/químicaRESUMO
The aim of this study was to characterise the bioactive compounds in mate (Ilex paraguariensis St. Hil) extract and in concentrated mate extract obtained by nanofiltration (NF). Also, the impact of NF on the antioxidant activity of both mate extracts was evaluated in vitro and using eukaryotic cells of Saccharomyces cerevisiae (yeast assay). The results showed a significant increase in the contents of total phenolics (338%), chlorogenic acid (483%), theobromine (323%), caffeine (251%), chlorophyll (321%), condensed tannins (278%) and saponins (211%) in the concentrated mate extract. The concentrated mate extract showed higher in vitro antioxidant activity than the mate extract. According to the results obtained, it can be stated that the use of nanofiltration membrane is a valid approach for the concentration of biologically active compounds in aqueous extract of mate.
Assuntos
Filtração/métodos , Ilex paraguariensis/química , Extratos Vegetais/isolamento & purificação , Cafeína/análise , Cafeína/isolamento & purificação , Ácido Clorogênico/análise , Ácido Clorogênico/isolamento & purificação , Filtração/instrumentação , Extratos Vegetais/análise , Saponinas/análise , Saponinas/isolamento & purificaçãoRESUMO
Chlorogenic acids (CGA) are cinnamic acid derivatives with biological effects mostly related to their antioxidant and antiinflammatory activities. Caffeoylquinic acids (CQA) and dicaffeoylquinic acids (diCQA) are the main CGA found in nature. Because green coffee is a major source of CGA, it has been used for production of nutraceuticals. However, data on the bioavailability of CGA from green coffee in humans are inexistent. The present study evaluated the pharmacokinetic profile and apparent bioavailability of CGA in plasma and urine of 10 healthy adults for 8 h after the consumption of a decaffeinated green coffee extract containing 170 mg of CGA. Three CQA, 3 diCQA, and caffeic, ferulic, isoferulic, and p-coumaric acids were identified in plasma by HPLC-Diode Array Detector-MS after treatment. Over 30% (33.1 +/- 23.1%) of the ingested cinnamic acid moieties were recovered in plasma, including metabolites, with peak levels from 0.5 to 8 h after treatment. CGA and metabolites identified in urine after treatment were 4-CQA, 5-CQA, and sinapic, p-hydroxybenzoic, gallic, vanillic, dihydrocaffeic, caffeic, ferulic, isoferulic, and p-coumaric acids, totaling 5.5 +/- 10.6% urinary recovery of the ingested cinnamic and quinic acid moiteties. This study shows that the major CGA compounds present in green coffee are highly absorbed and metabolized in humans.
Assuntos
Ácido Clorogênico/farmacocinética , Café/química , Café/metabolismo , Adulto , Disponibilidade Biológica , Ácidos Cafeicos/farmacocinética , Cafeína/isolamento & purificação , Ácido Clorogênico/administração & dosagem , Ácido Clorogênico/sangue , Ácido Clorogênico/urina , Cinamatos/farmacocinética , Ácidos Cumáricos/farmacocinética , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Propionatos , Ácido Quínico/análogos & derivados , Ácido Quínico/farmacocinética , Adulto JovemRESUMO
In this investigation, liquid carbon dioxide at 20 degrees C and 150 bar was used for the selective extraction of caffeine and theobromine from dry leaves of mate. A comparison between the chromatograms from CO2 extraction and traditional solvent extraction supports the selectivity of carbon dioxide for these purine alkaloids. The advantages of selective liquid CO2 extraction in terms of speed and resolution of UV/HPLC is also evidenced. A randomized block design of experiments was proposed to investigate the influence of 16 progenies of Ilex paraguariensis grown in 3 diverse sites on the contents of caffeine and theobromine in liquors of mate leaves obtained by extraction with compressed CO2. A significant effect of both these factors on the parameters investigated was observed by involving the F distribution in the statistical analysis. A cluster analysis based on the experimental uncertainties in the contents of these two methylxanthines has identified from four to six different groups of mate progenies.
Assuntos
Cafeína/isolamento & purificação , Dióxido de Carbono , Meio Ambiente , Ilex paraguariensis/química , Ilex paraguariensis/crescimento & desenvolvimento , Teobromina/isolamento & purificação , Cromatografia Líquida de Alta Pressão , Folhas de Planta/químicaRESUMO
The genus Paullinia includes the economically important P. cupana, known as guaraná in Brazil and more recently in the world market. Native Americans of the Maué and Andirá tribes cultivated P. cupana 'Sorbilis' in central Amazon, and the Barés cultivated the 'Typica' variety in the upper Negro River (Brazil). Cytological studies in the Sapindaceae family have concentrated on the diversity in number (from 2n = 14 to 96) and size of the chromosomes. In Paullinia, seven species have been karyotyped and all show 2n = 24. Meristem maceration, cellular dissociation and air-drying techniques were used for cytogenetic preparations and DNA content was determined by flow cytometry. Chromosome characterization and DNA content of Paullinia cupana Kunth 'Sorbilis' (Mart.) Ducke (Sapindaceae) were studied. The high chromosome number (2n = 210) fall into two cytomorphological groups: (a) a metacentric and submetacentric group showing 25 sets of three pairs of chromosomes (2-76); (b) a group containing only acrocentric showing 12 sets of two pairs of chromosomes (82-105), a homologous submetacentric pair (1) and an acrocentric pair (81). Mean nuclear DNA content of guaraná was 2C = 22.8 pg. A karyogram was set up showing a high chromosome number complement.
Assuntos
Genes de Plantas , Cariotipagem , Paullinia/genética , Brasil , Cafeína/isolamento & purificação , Mapeamento Cromossômico , Citometria de Fluxo , Metáfase , Clima TropicalRESUMO
The aim of this study was to study the convective drying of the hydroalcoholic extracts obtained from powdered guarana seeds in a spouted bed dryer. The influence of process variables, such as the convective airflow rate, extract feed rate, and air inlet temperature, on the quality of the dry extract was determined using the caffeine and moisture content for the process evaluation. The caffeine content in the alcoholic and dried extracts was determined by capillary gas chromatography. The experiments were performed following a 3(3) factorial design and the data analyzed by response surface. The analysis of dry extract showed that the air and extract feed rates did not significantly affect (25% level) the caffeine content, but that drying temperature is a major factor to consider when the extract is submitted to fluid bed drying. Caffeine losses were significant (1% level) for drying temperatures above 120 degrees C, while moisture content was lower than 3% for temperatures above 120 degrees C. The data showed that there is an optimum temperature for the drying of guarana extracts in spouted beds, and under the conditions used in this study it was 120 degrees C.
Assuntos
Cafeína/isolamento & purificação , Dessecação/métodos , Composição de Medicamentos/métodos , Extratos Vegetais/isolamento & purificação , Reologia/métodos , Teobromina/química , Teobromina/isolamento & purificação , Teofilina/química , Teofilina/isolamento & purificação , Cafeína/química , Dessecação/instrumentação , Composição de Medicamentos/instrumentaçãoRESUMO
New experimental data on the extraction of caffeine from guaraná seeds and maté tea leaves, and theobromine from cocoa beans, with supercritical CO2 were obtained using a high-pressure extraction apparatus. The effect of the addition of ethanol to carbon dioxide on the extraction efficiency was also investigated. Caffeine extraction yields of 98% of the initial caffeine content in both wet ground guaraná seeds and maté tea leaves were obtained. Extractions of caffeine from guaraná seeds and maté tea leaves also exhibited a retrograde behavior for the two temperatures considered in this work. In the removal of theobromine from cocoa beans, a much smaller extraction yield was obtained with longer extraction periods and consequently larger solvent requirements. The results of this study confirm the higher selectivity of CO2 for caffeine in comparison with that for theobromine, and also the influence of other components in each particular natural product on the extraction of methylxanthines. The effect of the addition of ethanol to carbon dioxide on the extraction of methylxanthines was significant, particularly in the extraction of theobromine from cocoa beans. In general, the use of ethanol results in lower solvent and energy requirements and thereby improved extraction efficiency.
Assuntos
Cacau/química , Cromatografia com Fluido Supercrítico , Ilex paraguariensis/química , Sapindaceae/química , Xantinas/isolamento & purificação , Cafeína/isolamento & purificação , Dióxido de Carbono , Etanol , Folhas de Planta/química , Sementes/química , Teobromina/isolamento & purificaçãoRESUMO
Caffeine and theobromine were identified and quantified in leaf epicuticular waxes of Ilex paraguariensis A. St.-Hil. (Aquifoliaceae). The total epicuticular leaf wax content was ca. 0.5% on average of dry leaf weight. Epicuticular caffeine and theobromine contents varied from 0.16 to 127.6 microg/mg and from 0 to 9.5 microg/mg of wax, respectively. For some selected samples, the intracellular methylxanthine concentration was also determined. A positive correlation was found between inner and epicuticular caffeine contents.
Assuntos
Cafeína/isolamento & purificação , Teobromina/isolamento & purificação , Cafeína/química , Calibragem , Cromatografia Líquida de Alta Pressão , Cromatografia em Camada Fina , Espectrofotometria Ultravioleta , Teobromina/químicaRESUMO
Experimental data for the supercritical CO(2) extraction of purine alkaloids (caffeine, theobromine, and theophylline) from ground herbal maté tea (Ilex paraguaryensis) using a high-pressure apparatus are presented. Caffeine, theophylline, and theobromine were identified in the extracted fractions using HPLC. Results indicated a much higher CO(2) selectivity for caffeine in comparison with those for theophylline and theobromine. Solubilities of pure compounds in carbon dioxide were also determined at 313.2, 323.2, 338.2, and 343.2 K, and pressures ranging from 14 to 24 MPa. Caffeine solubility exhibited a retrograde behavior with temperature while theophylline and theobromine manifested a normal behavior at conditions explored in this study. Solubilities in binary CO(2)/purine alkaloid model systems were much higher than those obtained during extraction of maté tea, demonstrating the difficulty of using binary data in predicting complex multicomponent behavior.
Assuntos
Bebidas/análise , Cafeína/isolamento & purificação , Teobromina/isolamento & purificação , Teofilina/isolamento & purificação , Cafeína/química , Dióxido de Carbono , Cromatografia Líquida de Alta Pressão/instrumentação , Cromatografia Líquida de Alta Pressão/métodos , Magnoliopsida , Pressão , Solubilidade , Teobromina/química , Teofilina/químicaRESUMO
Palicourea marcgravii (Rubiacea) is the major toxic plant to cattle in Brazil. We show the presence of the xanthinic alkaloid, caffeine, in this plant's leaves.