Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 15 de 15
Filtrar
Mais filtros











Intervalo de ano de publicação
1.
Foods ; 13(3)2024 Jan 24.
Artigo em Inglês | MEDLINE | ID: mdl-38338524

RESUMO

This research aimed to assess the influence of red dragon fruit peels ratio (RDF-PR) from two species, Hylocereus hybridum (HH) and Hylocereus undatus (HU), and particle size (PS) on quality parameters of red dragon fruit peel powder (RDF-PP) and its further application in emulsified alpaca-based sausages as partial substitutes of pork-back fat. A three-level full factorial design (nine treatments) was employed to evaluate the effect of RDF-PR (HH(0%):HU(100%), HH(50%):HU(50%), and HH(100%):HU(0%)) and PS (499-297, 296-177, and <177 µm) on the dependent variables: L*, a*, b*, C, h°, water-holding capacity, oil-holding capacity, swelling capacity, pectin yield, degree of esterification (analysed through FT-IR), and crude fibre content. The data analysed through a response surface methodology showed that treatment one (T1) is the best with the optimised conditions at 100% HU RDF-PR and PS of <177 µm. The statistical validation of T1 exhibited the highest water-holding capacity (32.1 g/g peel), oil-holding capacity (2.20 g oil/g peel), and pectin yield (27.1%). A completely randomised design (four formulations) was then used to assess the effect of partial replacement of pork-back fat by T1 in emulsified alpaca-based sausages on the colourimetric, physicochemical, and texture properties (hardness, chewiness, cohesiveness, springiness, adhesiveness, and adhesive force). Likewise, a sensory hedonic scale was employed to evaluate the appearance, colour, odour, flavour, texture, and overall acceptability of sausages. The results revealed that 65.7% of pork-back fat content was successfully replaced compared with a control formulation. Additionally, F3 showed significantly (p < 0.05) better colourimetric, physicochemical, and textural characteristics, such as lower hardness (34.8 N) and chewiness (21.7 N) and higher redness (a* = 19.3) and C (22.9), compared to a control formulation. This research presents RDF-PP as a promising fat substitute for developing healthier, reduced-fat meat products using fibre-rich agroindustry by-products.

2.
World J Microbiol Biotechnol ; 39(11): 290, 2023 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-37650985

RESUMO

This study aimed at estimating cultivation conditions to enable Yarrowia lipolytica NNRL Y-1095 to produce extracellular lipase and at evaluating the influence of magnetic fields (MF) on the lipase production and on its catalytic conditions. Culture conditions of carbon sources and surfactant defined to produce extracellular lipase were 10 g L-1 glucose, 15 g L-1 olive oil and 2 g L-1 Triton X-100. The highest lipase activity (34.8 U mL-1) was reached after 144 h when MFs were applied from 72 to 144 h of culture. It corresponds to an increase of 287.5% by comparison with the highest lipase activity in the control culture. MF application from 72 to 144 h did not change the optimal temperature of lipase, which was 37 °C, by comparison with the control. However, the optimal pH of the control was 7.0 while the one of lipase produced with MF was 8.0. Findings highlighted that the presence of MFs led to increase in synthesis of lipase by Y. lipolytica, with changes in the catalytic profile. This is one of the first studies of MF application to Y. lipolytica NRRL Y-1095 cultures to produce lipase.


Assuntos
Yarrowia , Carbono , Catálise , Lipase , Campos Magnéticos
3.
Anal Biochem ; 674: 115195, 2023 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-37268197

RESUMO

In this work, a quantitative sandwich ELISA was optimized, through a full factorial design of experiments (DOE) in successive steps of a preliminary protocol obtained by the method of one factor at a time (OFAT). The specificity of the optimized ELISA, the lower limit of quantification, the quantification range and the analytical sensitivity of the antigen quantification curve were evaluated, in comparison with the curve obtained from the preliminary protocol. The full factorial DOE was linked to a simple statistical processing, which facilitates the interpretation of the results in those laboratories where there is no trained statistician. The step-by-step optimization of the ELISA and the successive incorporation into the protocol of the best combination of factors and levels, allowed obtaining a specific immunoassay, with an analytical sensitivity 20 times greater and with a lower limit of antigen quantification that decreased from 156.25 at 9.766 ng/mL. As far as we know, there are no reports of optimization of an ELISA following the step-by-step scheme used in this work. The optimized ELISA will be used for the quantification of the TT-P0 protein, the active principle of a vaccine candidate against sea lice.


Assuntos
Antígenos , Ensaio de Imunoadsorção Enzimática/métodos , Imunoensaio
4.
AAPS PharmSciTech ; 24(4): 97, 2023 Apr 04.
Artigo em Inglês | MEDLINE | ID: mdl-37016118

RESUMO

The evaluation of the vehicle formulation is important during the development of sunscreens, as it influences their efficacy. In this context, the aim of the present study was to develop photoprotective formulations and evaluate the influence of the formulation components in the sun protection factor (SPF) and physical-mechanical and sensory properties of the formulations. We evaluated four sunscreens through a 22 full factorial design in terms of concentration and emulsifier type. The design of experiments (DOE) parameters were SPF, thixotropy, and work of shear. After the screening of the formulations by DOE, the SPF values, mechanical and sensory properties, and stability were evaluated. All study formulations showed non-Newtonian pseudoplastic behavior, compatible with sunscreens, and presented SPF values above 30. The factors evaluated in DOE had significant interactions for all the analyzed parameters. The concentration of the phosphate-based emulsifier influenced the SPF parameter. The work of shear was influenced by the concentration of polyglyceryl-based emulsifier. The concentration and the type of emulsifier influenced the thixotropy. Finally, effective sunscreens were developed, and the type and concentration of emulsifiers had an influence on the SPF of the formulations. In addition, the formulations chosen by DOE were stable and showed good sensory properties.


Assuntos
Fator de Proteção Solar , Protetores Solares , Emulsificantes , Excipientes , Raios Ultravioleta
5.
Arq. ciências saúde UNIPAR ; 26(3): 1019-1032, set-dez. 2022.
Artigo em Português | LILACS | ID: biblio-1414336

RESUMO

Arctium lappa L. é indicada no Formulário de Fitoterápicos da Farmacopeia Brasileira para o tratamento de distúrbios urinários leves. Estudos já demonstraram o potencial antioxidante, anti-inflamatório e antidiabético deste extrato, onde foram identificados fenóis, lignanas, taninos e flavonoides. O objetivo deste trabalho foi otimizar o método extrativo de raízes de A. lappa. Realizou-se o preparo de extratos por diferentes métodos: Ultrassom, Soxhlet, maceração e turbo extração. A otimização foi realizada por turbo extração seguindo um planejamento fatorial 23, empregando como fatores: teor alcoólico, concentração da matéria prima e tempo de extração. Os extratos foram avaliados quanto ao resíduo seco, teores de fenóis e flavonoides, e atividade antioxidante. Com relação ao resíduo seco, e aos teores de fenóis e flavonoides, os métodos de ultrassom e turbo extração demonstraram melhor poder extrativo. Devido ao menor tempo e custo operacional, a otimização foi realizada por turbo extração, e o extrato otimizado foi obtido utilizando álcool 60%, em proporção matéria prima solvente 1:10 e tempo de extração de 15 minutos. Estas análises poderão nortear futuros testes de transposição de método para escala industrial, diminuindo mão de obra, tempo e custos, visando obter produtos fitoterápicos mais eficientes, com valor acessível à população.


Arctium lappa L. is indicated in the Brazilian Pharmacopeia Herbal Medicines Form for the treatment of mild urinary disorders. Studies have already demonstrated the antioxidant, anti-inflammatory and antidiabetic potential of this extract, where phenols, lignans, tannins and flavonoids were identified. The objective of this work was to optimize the extractive method of A. lappa roots. Extracts were prepared by different methods: Ultrasound, Soxhlet, maceration and vortical extraction. The optimization was performed by vortical extraction following a 23 full factorial design, using as factors: alcohol content, drug concentration and extraction time. The extracts were evaluated for dry residue, phenols and flavonoids contents, and antioxidant activity. Regarding the dry residue, and the phenols and flavonoids contents, the ultrasound and vortical extraction methods showed better extractive power. Due to the lower operating time and cost, the optimization was performed by vortical extraction, and the optimized extract was obtained using 60% alcohol, in a 1:10 drug solvent ratio and extraction time of 15 minutes. These assessments guide the future tests of transposition of the method to an industrial scale, reducing manpower, time and costs, aiming to obtain more efficient phytotherapic products, with affordable value for the population.


Arctium lappa L. está indicado en la Formulacao de Fitoterápicos da Farmacopeia Brasileira para el tratamiento de trastornos urinarios leves. Los estudios han demostrado el potencial antioxidante, antiinflamatorio y antidiabético de este extracto, donde se identificaron fenoles, lignanos, taninos y flavonoides. El objetivo de este trabajo fue optimizar el método extractivo de las raíces de A. lappa. Los extractos se prepararon por diferentes métodos: Ultrasonido, Soxhlet, maceración y turboextracción. La optimización se realizó mediante turboextracción siguiendo una planificación factorial de 23, empleando como factores: tenor alcohólico, concentración de materia prima y tiempo de extracción. Se evaluaron los extractos para determinar el residuo seco, el contenido de fenoles y flavonoides y la actividad antioxidante. En cuanto al contenido de residuo seco, fenoles y flavonoides, los métodos de extracción por ultrasonidos y turbo demostraron un mejor poder de extracción. Debido al menor tiempo y coste operativo, la optimización se realizó mediante turboextracción, y el extracto optimizado se obtuvo utilizando alcohol 60%, en proporción disolvente-materia 1:10 y tiempo de extracción de 15 minutos. Estos análisis podrán orientar futuros ensayos de transposición del método para escala industrial, reduciendo mano de obra, tiempo y costes, con el objetivo de obtener productos fitoterapéuticos más eficientes, con valor accesible para la población.


Assuntos
Arctium/efeitos dos fármacos , Medicamento Fitoterápico , Otimização de Processos , Flavonoides/uso terapêutico , Preparações Farmacêuticas , Raízes de Plantas/efeitos dos fármacos , Compostos Fenólicos , Anti-Inflamatórios/uso terapêutico , Antioxidantes/uso terapêutico
6.
Arch Microbiol ; 204(8): 530, 2022 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-35900475

RESUMO

Microorganisms adapt to environmental conditions as a survival strategy for different interactions with the environment. The adaptive capacity of fungi allows them to cause disease at various sites of infection in humans. In this study, we propose digital images as responses of a complete factorial 23. Furthermore, we compared two experimental approaches: the experimental design (3D) and the checkerboard assay (2D) to know the influence of pH, glucose, and fluconazole concentration on different strains of the genus Candida. The digital images obtained from the factorial 23 were used as input in the PCA-ANOVA to analyze the results of this experimental design. pH modification in the culture medium modifies the susceptibility in some species less adapted to this type of modification. For the first time, to the best of our knowledge, digital images were used as input to PCA-ANOVA to obtain information on Candida spp.. Therefore, a higher concentration of antifungals is needed to inhibit the same strain at a lower pH. In short, we present an alternative with less use of reagents and time. In addition, the use of digital images allows obtaining information about fungal susceptibility with three or more factors.


Assuntos
Candida , Glucose , Antifúngicos/farmacologia , Quimiometria , Computadores , Farmacorresistência Fúngica , Fluconazol/farmacologia , Humanos , Concentração de Íons de Hidrogênio , Testes de Sensibilidade Microbiana
7.
Nat Prod Res ; 36(14): 3744-3749, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33461325

RESUMO

The ability to add value to waste materials from industrial operations has come to the attention of the wood processing industry, with reports, for example, of extracts from the bark tree conveying colour and UV protection to textile fibres. The objective of the present work was to expand our developments in this arena by using Copaifera langsdorffii Desf. bark extract as a natural dye for textile dyeing. A complete 2³-statistical experimental design and the central point was elaborated. The results showed that the optimal dyeing conditions were 98 °C, for 60 min, using undiluted bark extract. The dyed fabric was analysed by a spectrophotometer using the CIELAB system for evaluation of the colour strength. The results showed a K/S value of 5.78, and the dyed fabric had good colour fastness to rubbing and washing.


Assuntos
Corantes/isolamento & purificação , Fabaceae/química , Casca de Planta/química , Extratos Vegetais/química , Lã/química , Animais , Cor , Corantes/química , Extratos Vegetais/isolamento & purificação , Proteção Radiológica/métodos , Proteção Radiológica/normas , Espectrofotometria , Temperatura , Têxteis , Fatores de Tempo , Raios Ultravioleta , Lã/metabolismo
8.
Bioprocess Biosyst Eng ; 44(11): 2269-2276, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34155546

RESUMO

This work aims to produce bio-surfactant using a brewery waste (trub) as a strategy to reduce production costs related to the substrate, as well as to provide an eco-friendly destination for this residue. Trub is obtained during the boiling of the wort, being mainly composed of proteins and reducing sugars. To evaluate important process parameters on bio-surfactant production, a full factorial design (24) was elaborated, having agitation rate and concentrations of trub, yeast extract, and peptone as independent variables. The highest bio-surfactant concentration achieved was 100.76 mg L-1, where FTIR and Maldi-ToF-MS confirmed functional groups characteristic of peptides and isomers of surfactin in the bio-surfactant extract. Trub, agitation and yeast extract showed statistically significant effects on the response variable (surface tension), where an increase in the agitation rate and in the concentration of yeast extract demonstrated a positive impact on the production of bio-surfactant.


Assuntos
Cerveja , Carbono/metabolismo , Resíduos Industriais , Tensoativos/metabolismo , Fermentação , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Espectroscopia de Infravermelho com Transformada de Fourier , Tensão Superficial
9.
Eur J Pharm Biopharm ; 165: 127-148, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33992754

RESUMO

Nanotechnology has been widely applied to develop drug delivery systems to improve therapeutic performance. The effectiveness of these systems is intrinsically related to their physicochemical properties, so their biological responses are highly susceptible to factors such as the type and quantity of each material that is employed in their synthesis and to the method that is used to produce them. In this context, quality-oriented manufacturing of nanoparticles has been an important strategy to understand and to optimize the factors involved in their production. For this purpose, Design of Experiment (DoE) tools have been applied to obtain enough knowledge about the process and hence achieve high-quality products. This review aims to set up the bases to implement DoE as a strategy to improve the manufacture of nanocarriers and to discuss the main factors involved in the production of the most common nanocarriers employed in the pharmaceutical field.


Assuntos
Portadores de Fármacos/química , Composição de Medicamentos/métodos , Nanopartículas/química , Projetos de Pesquisa , Química Farmacêutica , Nanomedicina/métodos
10.
Rev. colomb. quím. (Bogotá) ; 49(2): 3-11, mayo-ago. 2020. tab, graf
Artigo em Espanhol | LILACS-Express | LILACS | ID: biblio-1115656

RESUMO

Resumen Los lípidos polares de las microalgas sor de gran interés debido a su aplicación como ingredientes naturales novedosos para las industrias cosmética, nutricional y farmacéutica. Por ello, el presente trabajo buscó determinar el efecto de los principales factores en la extracción e identificación de los lípidos polares de las microalgas Nannochloropsis oceanica y Desmodesmus asymmetricus, mediante el diseño de superficie de respuesta de Box-Behnken y el diseño factorial completo, respectivamente. Estas cepas del Banco de Germoplasma de Organismos Acuáticos (BGOA - IMARPE) fueron cultivadas en un invernadero, en biorreactores de 30 litros, centrifugadas y liofilizadas. Los lípidos fueron extraídos con cloroformo-metanol, fraccionados y analizados con un espectrómetro de masas Waters Xevo G2-XS QTOF. La maximización de la extracción de los lípidos totales determinó un valor óptimo de la relación masa-solvente de 25mg/3 mL, una proporción 1:1 de cloroformo-metanol, aproximadamente, y un tiempo del baño de ultrasonido entre 10 y 30 min. Los principales lípidos polares identificados para N. oceanica fueron lisofosfatidilcolina (LPC), diacilgliceril-N,N,N-trimetilhomoserina (DGTS), digalactosil diacilglicerol (DGDG) y monogalactosil diacilglicerol (MGDG) y para D. asymmetricus fueron sulfoquinovosil diacilglicerol (SQDG), LDGTS, DGTS, DGDG y MGDG.


Abstract The microalgae polar lipids are of great interest due to their application as novel natural ingredients for the cosmetic, nutritional, and pharmaceutical industry. For this reason, the present work sought to determine the effect of the main factors in the extraction and identification of polar lipids from the microalgae Nannochloropsis oceanica and Desmodesmus asymmetricus, using Box-Behnken response surface methodology design and full factorial design, respectively. These strains from the Germplasm Bank of Aquatic Organisms (BGOA - IMARPE) were grown in a greenhouse, in 30 L bioreactors, centrifuged and lyophilized. The lipids were extracted with chloroform-methanol, fractionated and analyzed with the Waters Xevo G2-XS QTOF mass spectrometer. The maximization of total lipid extraction determined an optimal value of the mass-solvent ratio of 25 mg / 3 mL, an approximate ratio of chloroform-methanol 1:1 and an ultrasound bath time between 10 and 30 min. The main polar lipids identified for the N. oceanica microalgae were lysophophatidylcholine (LPC), diacylglyceryl-N,N,N-trimethylhomoserine (DGTS), digalactosyldiacylglycerol (DGDG), and monogalactosyldiacylglycerol (MGDG) and for D. asymmetricus were sulfoquinovosyl diacylglycerol (SQDG), LDGTS, DGTS, DGDG, and MGDG.


Resumo Os lipídios polares das microalgas possuem grande interesse em sua aplicação como novos ingredientes naturais na indústria cosmética, nutricional e farmacêutica. A presente pesquisa procura determinar o efeito dos principais fatores na extração e identificação dos lipídios polares das microalgas Nannochloropsis oceanica e Desmodesmus asymmetricus, por meio do um experimento de Box-Behnken e um experimento fatorial completo, respectivamente. As cepas do Banco do Germoplasma do Organismos Aquáticos (BGOA - IMARPE), foram cultivadas em casa de vegetação, em biorreatores do 30 L, centrifugadas e liofilizadas. Os lipídios foram extraídos com clorofórmio-metanol, fracionados e analisados com o espectrómetro do massa Waters Xevo G2-XS QTOF. A maximização da extração lipídica determinou um valor ótimo da razão massa-solvente de 25 mg / 3 mL, uma proporção aproximadamente clorofórmio-metanol de 1:1 e no tempo do banho de ultrassom entre 10 e 30 minutos. Os principais lipídios polares identificados para das microalgas N. oceanica foram lisofosfatidilcolina (LPC), diacilgliceril-N,N,N-trimetil-homoserina (DGTS), digalactosil diacilglicerol (DGDG) e monogalactosil diacilglicerol (MGDG), e para D. asymmetricus foram sulfoquinovosil diacilglicerol (SQDG), LDGTS, DGTS, DGDG e MGDG.

11.
Int J Biol Macromol ; 146: 431-443, 2020 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-31904462

RESUMO

Pressurized hot water extraction (PHWE), known as a "green" extraction technique, was used to obtain polysaccharide from the pulp of gabiroba (Campomanesia xanthocarpa Berg) fruits. The effects of pressure, temperature, and flow rate on pectin yields were analyzed through a full factorial design experiment 23. The optimal extraction conditions to achieve maximum pectin yield (5.70 wt%) were pressure of 150 bar, temperature of 120 °C, and flow rate of 1.5 mL min-1. The high pressure (100 bar) promoted an increase in galacturonic acid content (36.0%) compared to conventional hot water extraction (CEGP) with 25.7%. Differences in the proportion of homogalacturonan (HG) and rhamnogalacturonan (RG-I) domains ranging from 16.3 to 35.4% and 61.7 to 80.1%, respectively, were observed for each pectin sample according to the extraction conditions. The mono-dimensional (13C-NMR) and bi-dimensional (1H/13C HSQC-NMR) analyses confirmed the presence of HG and RG-I regions and indicated the presence of arabinogalactans type I (AG-I) and arabinogalactans type II (AG-II) in the PHWE pectin samples, which was not found for pectins from gabiroba pulp obtained by CEGP. The results showed that PHWE proved to be a promising method for extracting pectins from gabiroba fruits.


Assuntos
Frutas/química , Temperatura Alta , Myrtaceae/química , Pectinas/química , Pectinas/isolamento & purificação , Pressão , Água/química , Espectroscopia de Ressonância Magnética Nuclear de Carbono-13 , Monossacarídeos/análise , Espectroscopia de Prótons por Ressonância Magnética , Análise de Regressão
12.
Braz. J. Pharm. Sci. (Online) ; 56: e18070, 2020. tab, graf
Artigo em Inglês | LILACS-Express | LILACS | ID: biblio-1089193

RESUMO

The objective of this study was to determine specific combination of pharmaceutical excipients that lead to formulation of efficient nebivolol hydrochloride SMEDDS and its subsequent formulation into IR-SET (Immediate release- Self emulsifying tablet) which will enhance its solubility and dissolution. Solubility and Pseudo-ternary phase studies were carried out to identify the excipients showing highest solubility and to identify the zone of microemulsion with selected ingredients. Liquid-SMEDDS (L-SMEDDS) were optimized for Concentration of oil(X1) and Smix(X2) and formulated using a combination of Kollisolv GTA as oil, Tween 80 as surfactant and propylene glycol as co-surfactant which gave smaller droplet size(Y1) 55.98nm , Emulsification time (Y2) 16±1.5 s,% transmittance (Y3) 99.94±0.47%. Neusilin US2 was used as solid carrier for solidification of L-SMEDDS in to Solid-SMEDDS (S-SMEDDS) by adsorption technique. IR-SET of nebivolol were formulated with S-SMEDDS and optimized for the concentration of binder (X1) (PVP K30) and superdisintegrant (X2) (KOLLIDON CL) which showed low Disintegration time (Y1) (92±0.5s) and low Friability(Y2)(0.424±0.03%). Also the DSC and XRD data revealed the molecular state of the drug in S-SMEDDS. The extent of in-vivo drug release and ex-vivo diffusion values from L-SMEDDS and IR-SET was much higher than pure drug and marketed tablet. In conclusion, the results showed potential of SMEDDS to improve solubility and thus the bioavailability.

13.
Braz. J. Pharm. Sci. (Online) ; 56: e18069, 2020. tab, graf
Artigo em Inglês | LILACS-Express | LILACS | ID: biblio-1089210

RESUMO

Present study was aimed to prepare and characterize fluconazole loaded nanostructured lipid carriers (FLZ-NLCs) for the treatment of fungal infections. Fungal infections are tremendously widespread and are the often faced dermatological condition worldwide. FLZ-NLCs was prepared by ultrasonication emulsion technique using stearic acid (SA) as solid lipid, castor oil as liquid lipid and tween 20 as a surfactant. The mean diameter of optimized FLZ-NLCs were found to be 359.15 ± 9.83 nm. The drug content and entrapment efficiency of NLCs was found to be 102.97 ± 7.45% and 87 ± 0.59%, respectively. In vitro drug release studies of FLZ-NLCs showed 37.34 ± 2.08% drug release over a period of 72 h. The above studies confirmed the prepared FLZ-NLCs may be useful for the treatment of fungal infections.

14.
Food Chem ; 294: 405-413, 2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31126481

RESUMO

In the present paper, a new analytical preconcentration/speciation method for antimony species determination in bottled mineral water samples using the SiO2/Al2O3/SnO2 adsorbent was developed. The method is based on selective adsorption of Sb(III) ions by SiO2/Al2O3/SnO2 under a wide pH range (2.5-7.5). Total antimony was determined with previous sample treatment using 0.1% (w/v) l-cysteine and the concentration of Sb(V) species was determined by the difference between total and Sb(III). The proposed method provided an analytical curve ranging from 0.50 to 5.00 µg L-1 (r = 0.999), limit of detection (LD) of 0.17 µg L-1 and preconcentration factor (PF) of 136-fold. The method exhibited tolerance to different metal ions and the accuracy was attested from addition and recovery tests (95.2-106.0%) in bottled mineral water samples using 2.0% (w/v) l-cysteine, as well as by analysis of certified material. Only Sb(III) species were determined in mineral water (0.54-1.04 µg L-1).


Assuntos
Antimônio/análise , Água Potável/análise , Águas Minerais/análise , Espectrofotometria Atômica/métodos , Óxido de Alumínio/química , Antimônio/química , Cisteína/química , Análise de Injeção de Fluxo , Limite de Detecção , Oxirredução , Dióxido de Silício/química , Compostos de Estanho/química
15.
Environ Sci Pollut Res Int ; 26(5): 5131-5139, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30607853

RESUMO

This study proposed the optimization of a laccase-mediator system to reduce pesticide levels (bentazone, carbofuran, diuron, clomazone, tebuconazole, and pyraclostrobin) on aqueous medium. Firstly, the mediator concentration of 1 mM was established (average removal of 36%). After that, seven redox-mediating compounds, namely, 2,20-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt, caffeic acid, chlorogenic acid, p-coumaric acid, ferulic acid, gallic acid, protocatechuic acid, and vanillin, were compared regarding their removal efficiency. The highest removal (77%) was achieved with the laccase-vanillin system. After this screening, the optimization was carried out by a 22 full factorial design. Variables under study were the enzyme (laccase) activity and vanillin concentration. Maximum removal (53-85%) was achieved with 0.95 U/mL laccase and 1.8 mM vanillin. Pesticide removal in reaction media was fitted to the first-order kinetics equation with an average half-time life of 2.2 h. This is the first study of the use of this natural compound as a mediator in the degradation of the pesticides under investigation. The results of this study contribute, with alternative methods, to decrease pesticide levels since they are highly persistent in aqueous samples and, as a result, mitigate the environmental impact.


Assuntos
Benzaldeídos/química , Lacase/metabolismo , Praguicidas/análise , Poluentes Químicos da Água/análise , Benzaldeídos/metabolismo , Biodegradação Ambiental , Catálise , Cinética , Oxirredução , Praguicidas/metabolismo , Trametes/enzimologia , Poluentes Químicos da Água/metabolismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA