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1.
J Agric Food Chem ; 68(8): 2562-2569, 2020 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-32003990

RESUMO

This study was aimed to evaluate the level of furan and acrylamide contamination in cocoa and noncocoa raw materials, in masses from processing stages, and in chocolates originating from three factories. Acrylamide was determined by the gas chromatography-mass spectrometry (GC-MS) method using the QuEChERS procedure with dispersive solid-phase extraction clean-up and isotopic standard (2,3,3-d3-acrylamide). Furan was analyzed by the headspace solid-phase microextraction/GC-MS technique with the d4-furan marker. Both analytical methods were validated in terms of accuracy, precision, and linearity as well as the limit of detection (LOD) and limit of quantification (LOQ). Among all raw materials, the most abundant in acrylamide were cocoa masses and powders (83.0-127.5 ng g-1). Roasting of cocoa beans increased the content of acrylamide 2-3-fold. The obtained results indicate that acrylamide might be formed during wet conching. Only in cocoa powders and lecithin, it was possible to quantify furan (3.7-10.2 and 16.3 ng g-1, respectively). Roasting of cocoa beans increased the content of furan from

Assuntos
Acrilamida/análise , Cacau/química , Chocolate/análise , Furanos/análise , Acrilamida/isolamento & purificação , Contaminação de Alimentos/análise , Manipulação de Alimentos , Furanos/isolamento & purificação , Cromatografia Gasosa-Espectrometria de Massas , Sementes/química , Microextração em Fase Sólida
2.
Molecules ; 24(20)2019 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-31623227

RESUMO

Acrylamide and 5-hydroxymethyl-2-furfural (5-HMF) are two of the most abundant compounds generated during thermal processing. A simple method for the simultaneous quantitation of acrylamide and 5-HMF was developed and successfully applied in thermally processed foods. Acrylamide and 5-HMF were co-extracted with methanol and then purified and enriched by an Oasis HLB solid-phase extraction cartridge, simultaneously analyzed by high-performance liquid chromatography and detected with a diode array detector, respectively, at their optimal wavelength. The linear concentration range was found to be 25-5000 µg/L with high linear correlation coefficients (R > 0.999). The limit of detection and the limit of quantitation for acrylamide and 5-HMF were 6.90 µg/L and 4.66 µg/L, and 20.90 µg/L and 14.12 µg/L, respectively. The recovery of acrylamide and 5-HMF in biscuits, bread, Chinese doughnuts, breakfast cereals, and milk-based baby foods was achieved at 87.72-96.70% and 85.68-96.17% with RSD at 0.78-3.35% and 0.55-2.81%, respectively. The established method presents simplicity, accuracy and good repeatability, and can be used for the rapid simultaneous quantitation of acrylamide and 5-HMF in thermally processed foods.


Assuntos
Acrilamida/química , Acrilamida/isolamento & purificação , Análise de Alimentos , Furaldeído/análogos & derivados , Análise de Alimentos/métodos , Análise de Alimentos/normas , Furaldeído/química , Furaldeído/isolamento & purificação , Temperatura Alta , Limite de Detecção
3.
J Agric Food Chem ; 67(17): 5017-5025, 2019 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-30839206

RESUMO

The goal of this study was to develop a method for simultaneous determination of acrylamide (AA) and 5-hydroxymethylfurfural (5-HMF) in heat-processed foods by liquid chromatography-tandem mass spectrometry analysis. Several cleanup methods for the quick, easy, cheap, effective, rugged, and safe (QuEChERS) protocol were investigated and compared: (a) dispersive solid-phase extraction (d-SPE) with Enhanced Matrix Removal-Lipid (EMR-Lipid), (b) d-SPE with primary secondary amine, (c) without the cleanup step, and (d) cleanup with n-hexane. It is the first time that EMR-Lipid sorbent has been used as a d-SPE material to detect AA and 5-HMF in heat-processed foods, and among the four cleanup methods, the EMR-Lipid method provided the best cleanup of co-extracted matrix interferences and the highest extraction efficiency. Validation experiments were carried out for the method using EMR-Lipid as the d-SPE sorbent. Excellent linearity ( R2 > 0.999) was achieved, and the limits of detection (LODs) of AA and 5-HMF were 2.5 and 12.5 µg/kg, respectively. The recoveries of AA and 5-HMF levels obtained were in the ranges of 87.3-103.3 and 83.2-104.3%, with precision [relative standard deviations (RSDs)] of 1.2-6.8 and 1.4-7.4% ( n = 3), respectively. The method is accurate and reliable and was successfully applied to analyze the AA and 5-HMF in eight categories of Chinese heat-processed foods.


Assuntos
Acrilamida/análise , Acrilamida/isolamento & purificação , Furaldeído/análogos & derivados , Extração em Fase Sólida/métodos , Cromatografia Líquida/métodos , Culinária , Contaminação de Alimentos/análise , Furaldeído/análise , Furaldeído/isolamento & purificação , Temperatura Alta , Limite de Detecção , Lipídeos/química , Extração em Fase Sólida/instrumentação , Espectrometria de Massas em Tandem/métodos
4.
Food Chem ; 275: 95-104, 2019 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-30724265

RESUMO

This study reports on removal of acrylamide from roasted coffee by acrylamidase from Cupriavidus oxalaticus ICTDB921. Chitosan coated calcium alginate beads were functionalized with citric acid as nontoxic cross linker and activated by 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride (EDC) and N-hydroxysuccinimide (NHS) (1.66:1 w/w) for covalent immobilization of acrylamidase. The optimum beads were obtained using 5% sodium alginate, 1.5% chitosan, and 0.6 mol/L citric acid. The beads prepared at each step were characterized by FTIR and SEM. Coating of chitosan matrix on calcium alginate beads enhanced the mechanical stability over that of calcium alginate and/or chitosan. The immobilized acrylamidase showed optimum pH/temperature of 8.5/65 °C, improved pH/thermal/shelf stability, and retained 80% activity after four cycles. Haldane model could describe the degradation kinetics of acrylamide in batch study. In packed bed column, a bed height, feed flow rate and inlet acrylamide concentration of 20 cm, 1 mL/min, and 100 mg/L gave best results.


Assuntos
Acrilamida/isolamento & purificação , Alginatos/química , Amidoidrolases/química , Quitosana/química , Café/química , Enzimas Imobilizadas/química , Manipulação de Alimentos/métodos , Burkholderiaceae/enzimologia , Carbodi-Imidas/química , Enzimas Imobilizadas/metabolismo , Manipulação de Alimentos/instrumentação , Concentração de Íons de Hidrogênio , Cinética , Microscopia Eletrônica de Varredura , Espectroscopia de Infravermelho com Transformada de Fourier , Succinimidas/química , Temperatura
5.
Food Chem ; 282: 120-126, 2019 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-30711095

RESUMO

This work has proposed the application of optimized dispersive liquid-liquid microextraction (DLLME) in order to extract acrylamide from brewed coffee samples for its subsequent determination by ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS). DLLME achieved superior results employing 300 µL of brewed coffee, 100 µL of dichloromethane, 400 µL of acetonitrile and without sodium chloride addition. Quantitative analyses were carried out by the standard addition method, and the limits of detection and quantification were 0.9 and 3.0 µg L-1, respectively. Recoveries ranged from 97 to 106%, and the intra- and inter-assay precisions ranged from 6 to 9%. The proposed analytical method was applied to seventeen brewed coffee samples prepared in a filter coffee maker, and acrylamide amounts varied from 10.5 to 28.5 µg L-1. Therefore, the suggested DLLME-UPLC-MS/MS method is promising for routine analysis in order to guarantee the quality control of acrylamide in brewed coffee.


Assuntos
Acrilamida/análise , Café/química , Espectrometria de Massas em Tandem , Acrilamida/isolamento & purificação , Cromatografia Líquida de Alta Pressão , Café/metabolismo , Limite de Detecção , Microextração em Fase Líquida/métodos
6.
Food Chem ; 274: 55-60, 2019 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-30372978

RESUMO

A single-drop microextraction method followed by gas chromatography-electron capture detection was developed to determine acrylamide in food samples. Acrylamide was extracted by water and derivatized by hydrobromic acid in the presence of ammonium peroxydisulfate. The derivatization was carried out at 45 °C in 15 min using 46 µL of hydrobromic acid and 98 mg of ammonium peroxydisulfate. A 3.0-mL volume of the derivatized analyte was extracted using a 1.0-µL n-octanol droplet hanging from the needle tip of a GC microsyringe. After extraction, the extract was injected into the gas chromatograph. The influence of experimental parameters effective on derivatization reaction yield and extraction performance was studied. The limit of detection and quantification, relative standard deviation and linearity of the method were 0.60 µg/L, 2.0 µg/L, <6.0%, and 2.0-100.0 µg/L, respectively. The method was utilized to determine acrylamide in three food samples (i.e., bread, potato chips and cookie).


Assuntos
Acrilamida/análise , Cromatografia Gasosa/métodos , Análise de Alimentos/métodos , Cromatografia Gasosa-Espectrometria de Massas/métodos , Acrilamida/isolamento & purificação , Pão/análise , Fracionamento Químico/instrumentação , Fracionamento Químico/métodos , Elétrons , Análise de Alimentos/instrumentação , Cromatografia Gasosa-Espectrometria de Massas/instrumentação , Limite de Detecção , Solanum tuberosum , Água/química
7.
Food Chem ; 271: 54-61, 2019 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-30236713

RESUMO

Acrylamide a neurotoxin and strong carcinogen, is found in various thermally processed foods. In this study, an electrochemical sensor for detection of acrylamide using double stranded DNA (dsDNA)/Hemoglobin (Hb)-modified screen printed gold electrode (SPGE) was designed. The immobilization of ssDNA1-SH on the surface of SPGE was confirmed by cyclic voltammetry, and the interaction between ssDNA2-NH2 and Hb with the ratio 1:1 was characterized by agarose gel. The excellent response of the designed biosensor towards acrylamide due to acrylamide and Hb adducts and change of reduction/oxidation process of Hb-Fe(III)/Hb-Fe(II) was determined by square wave voltammetry (SWV). The biosensor showed the optimum response at pH 8.0. The linear working range for acrylamide was from 2.0 × 10-6 to 5.0 × 10-2 M with a detection limit of 1.58 × 10-7 M. The biosensor was suitable for direct determination of acrylamide in water extracted of potato fries and displayed good reproductivity and high stability.


Assuntos
Acrilamida/química , Técnicas Biossensoriais/métodos , Técnicas Eletroquímicas/métodos , Contaminação de Alimentos/análise , Solanum tuberosum/química , Acrilamida/isolamento & purificação , Eletrodos , Compostos Férricos , Hemoglobinas , Oligonucleotídeos
8.
Int J Biol Macromol ; 107(Pt A): 1000-1013, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-28965965

RESUMO

The nanoparticles of haemoglobin (HbNPs) were prepared by desolvation method and characterized by transmission electron microscopy (TEM),UV-vis spectroscopy, Fourier transformation infra red (FTIR) spectroscopy and X-ray diffraction (XRD) and atomic force microscopy (AFM). Protein profile of HbNPs was also studied by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). An amperometric acrylamide biosensor was constructed by immobilizing covalently HbNPs onto polycrystalline Au electrode. The Au electrode was characterized by scanning electron microscopy (SEM) and electrochemical impedance spectra (EIS) before and after immobilization of HbNPs. The biosensor showed optimum current response within 2s at 0.26V, pH 5.0 at room temperature (20°C). The biosensor measured the acrylamide concentration in processed foods. The working range of biosensor was 0.1nm-100mM with a limit of detection (LOD) as low as 0.1nM. The biosensor measured acrylamide concentration in various processed foods such as biscuits, bread, potato crisps, "kurkure", nuts and fried cereals. The analytical recovery of added acrylamide in aqueous extract of food at 5 and 10mM was 99% and 98% respectively. Within-and between-batch, co-efficient of variations were 3.85% and 4.67% respectively. The structural analogs of acrylamide such as acrylic acid and propionic acid had practically no interference on the biosensor.


Assuntos
Acrilamida/isolamento & purificação , Técnicas Biossensoriais/métodos , Hemoglobinas/química , Nanopartículas/química , Acrilamida/química , Acrilamida/toxicidade , Manipulação de Alimentos , Humanos , Limite de Detecção , Microscopia de Força Atômica , Espectroscopia de Infravermelho com Transformada de Fourier , Difração de Raios X
9.
Int J Biol Macromol ; 96: 93-99, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-27919811

RESUMO

A novel L-asparaginase gene (PbAsnase) from Paenibaeillus barengoltzii CAU904 was cloned and expressed in Escherichia coli. The L-asparaginase gene was 1011bp encoding 336 amino acids. Multiple sequence alignment of PbAsnase with other known L-asparaginases revealed that the enzyme showed high similarities with some Rhizobial-type L-asparaginases, sharing the highest identity of 32% with a characterized L-asparaginase from Rhizobium etli CFN 42, suggesting that it should be a novel L-asparaginase. The recombinant L-asparaginase (PbAsnase) was purified to homogeneity and biochemically characterized. The purified enzyme was optimally active at pH 8.5 and 45°C, respectively. It was stable within pH 5.5-10.0 and at temperatures below 55°C. PbAsnase exhibited strict substrate specificity towards L-asparagine (35.2U/mg), with Km and Vmax values of 3.6mM and 162.2µmol/min/mg, respectively, but displayed trace activity towards L-glutamine. Moreover, the application potential of PbAsnase on acrylamide migration in potato chips and mooncakes was evaluated. The pretreatment by PbAsnase significantly decreased the acrylamide contents in potato chips and mooncakes by 86% and 52%, respectively. The unique properties of PbAsnase may make it a good candidate in industries, especially in food safety.


Assuntos
Acrilamida/metabolismo , Asparaginase/química , Asparaginase/metabolismo , Manipulação de Alimentos , Paenibacillus/enzimologia , Solanum tuberosum/química , Acrilamida/isolamento & purificação , Sequência de Aminoácidos , Asparaginase/genética , Clonagem Molecular , Estabilidade Enzimática , Concentração de Íons de Hidrogênio , Cinética , Oxirredução , Análise de Sequência , Especificidade por Substrato
10.
J Chromatogr A ; 1459: 17-23, 2016 Aug 12.
Artigo em Inglês | MEDLINE | ID: mdl-27423776

RESUMO

Nine crosslinked polymeric ionic liquid (PIL)-based SPME sorbent coatings were designed and screened in this study for the trace level determination of acrylamide in brewed coffee and coffee powder using gas chromatography-mass spectrometry (GC-MS). The structure of the ionic liquid (IL) monomer was tailored by introducing different functional groups to the cation and the nature of the IL crosslinker was designed by altering both the structure of the cation as well as counteranions. The extraction efficiency of the new PIL coatings towards acrylamide was investigated and compared to a previously reported PIL sorbent coating. All PIL fibers exhibited excellent analytical precision and linearity. The PIL fiber coating consisting of 50% 1,12-di(3-vinylbenzylbenzimidazolium)dodecane dibis[(trifluoromethyl)sulfonyl]imide as IL crosslinker in 1-vinyl-3-(10-hydroxydecyl)imidazolium bis[(trifluoromethyl)sulfonyl]imide IL monomer resulted in a limit of quantitation of 0.5µgL(-1) with in-solution SPME sampling. The hydroxyl moiety appended to the IL cation was observed to significantly increase the sensitivity of the PIL coating toward acrylamide. The quantitation of acrylamide in brewed coffee and coffee powder was performed using the different PIL-based fibers by the method of standard addition after a quenching reaction using ninhydrin to inhibit the formation of interfering acrylamide in the GC inlet, mainly by asparagine thermal degradation. Excellent repeatability with relative standard deviations below 10% were obtained on the real coffee samples and the structure of the coatings appeared intact by scanning electron microscopy after coffee sampling proving the matrix-compatibility of the PIL sorbent coatings.


Assuntos
Acrilamida/análise , Café/química , Cromatografia Gasosa-Espectrometria de Massas , Líquidos Iônicos/química , Polímeros/química , Microextração em Fase Sólida , Acrilamida/isolamento & purificação , Íons/química , Microscopia Eletrônica de Varredura
11.
Talanta ; 146: 417-22, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26695284

RESUMO

Acrylamide is a potentially toxic and carcinogenic substance present in many high-consumption foods. Recently, this matter has been placed in category of "reasonably anticipated to be a human carcinogen" by National Toxicology Program (NTP). Therefore, simple and cost-effective determination of acrylamide in food samples has attracted intense interest. The most reported techniques for this purpose are GC-MS and LC-MS, which are very expensive and available in few laboratories. In this research, for the first time, a rapid, easy and low-cost method is introduced for sensitive and precise determination of acrylamide in foodstuffs, using gas chromatography-flame ionization detection (GC-FID) system after its direct trapping in the upper atmosphere of samples by headspace solid-phase microextraction (HS-SPME). The effects of main experimental variables were studied and the optimized parameters were obtained as the type of fiber, carboxen/divinylbenzene/polydimethylsiloxane (CAR/DVB/PDMS); extraction time, 30 min; extraction temperature, 60°C; moisture content, 10 µL water per 1g of sample; desorption time, 2 min; and desorption temperature, 230°C. The linear calibration graph was obtained in the range of 0.77-50 µg g(-1), with regression coefficient of 0.998. The detection and quantification limits of the proposed method were 0.22 and 0.77 µg g(-1), respectively. The recoveries, for different food samples, were 79.6-95.7%. The repeatability of measurements, expressed as relative standard deviation (RSD), were found to be 4.1-8.0% (n=9). The proposed HS-SPME-GC-FID method was successfully carried out for quantifying of trace levels of acrylamide in some processed food products (chips and French fries), sold in open local markets.


Assuntos
Acrilamida/análise , Acrilamida/isolamento & purificação , Cromatografia Gasosa/métodos , Contaminação de Alimentos/análise , Manipulação de Alimentos , Solanum tuberosum/química , Microextração em Fase Sólida/métodos , Acrilamida/química , Cromatografia Gasosa/normas , Padrões de Referência , Temperatura
12.
Artigo em Inglês | MEDLINE | ID: mdl-26414298

RESUMO

The paper investigates the migration of the acrylamide monomer (AMD) to lettuce chosen as a test plant growing in an organic medium (peat substrate). Polyacrylamide (PAM)-based flocculant added to the growing medium contained no more than 1000 mg kg(-1) of AMD. Plants were grown with varied doses of PAM preparation (0.5-3.0 mg dm(-3) of peat substrate) to compare the results with the control sample. The determination of AMD content, chlorophyll content, weight of the lettuce head, and also analysis of macro- and micro-elements in lyophilised test material was made under the same analytical conditions. The results showed that lettuce plants absorb AMD to the leaves from the peat substrate. The AMD uptake has a negative impact on the growth of lettuce. It reduces the average fresh weight of heads and destabilises the mineral composition of the plant. Therefore, concern related to the transfer risk of the residual AMD from sludge used for organic fertilisation of edible plants still remains a crucial question from a food and consumer safety point of view. To ensure consumer safety, the fate of the AMD following the application of PAM to cropland should be carefully monitored in the whole food chain.


Assuntos
Acrilamida/isolamento & purificação , Resinas Acrílicas/isolamento & purificação , Lactuca/química , Folhas de Planta/química , Poluentes do Solo/isolamento & purificação , Acrilamida/metabolismo , Resinas Acrílicas/metabolismo , Clorofila/análise , Clorofila/biossíntese , Cromatografia Líquida de Alta Pressão , Floculação , Inocuidade dos Alimentos , Humanos , Lactuca/efeitos dos fármacos , Lactuca/metabolismo , Folhas de Planta/efeitos dos fármacos , Folhas de Planta/metabolismo , Solo/química , Poluentes do Solo/metabolismo
13.
Bioresour Technol ; 187: 198-204, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25846190

RESUMO

In this work, multiple reuses of Rhodococcus ruber TH3 free cells for the hydration of acrylonitrile to produce acrylamide in a membrane dispersion microreactor were carried out. Through using a centrifuge, the reactions reached 39.9, 39.5, 38.6 and 38.0wt% of the final acrylamide product concentration respectively within 35min in a four cycle reuse of free cells. In contrast, using a stirring tank, free cells could only be used once with the same addition speed of acrylonitrile with a microreactor. Through observing the dissolution behavior of acrylonitrile microdroplets in a free cell solution using a coaxial microfluidic device and microscope, it was found that the acrylonitrile microdroplets with a diameter of 75µm were rarely observed within a length of 2cm channel within 10s, which illustrated that the microreactor can intensify the reaction rate to reduce the inhibition of acrylonitrile and acrylamide.


Assuntos
Acrilamida/metabolismo , Reatores Biológicos/microbiologia , Membranas Artificiais , Reciclagem/métodos , Rhodococcus/classificação , Rhodococcus/metabolismo , Acrilamida/isolamento & purificação , Especificidade da Espécie
14.
Crit Rev Anal Chem ; 44(2): 107-41, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25391433

RESUMO

Acrylamide (AA) is a compound classified as carcinogenic to humans by the International Agency for Research on Cancer. It was first discovered to be present in certain heated processed food by the Swedish National Food Administration (SNFA) and University of Stockholm in early 2002. The major pathway for AA formation in food is the Maillard reaction between reducing sugar and the amino acid asparagine at high temperature. Since the discovery of AA's presence in food, many analytical methods have been developed for determination of AA contents in different food matrices. Also, several studies have been conducted to develop extraction procedures for AA from difficult food matrices. AA is a small, highly polar molecule, which makes its extraction and analysis challenging. Many articles and reviews have been published dealing with AA in food. The aim of the review is to discuss AA formation in food, the factors affecting AA formation and removal, AA exposure assessment, AA extraction and cleanup from food samples, and analytical methods used in AA determination, such as high-performance liquid chromatography (HPLC) and gas chromatography (GC). Special attention is given to sample extraction and cleanup procedures and analytical techniques used for AA determination.


Assuntos
Acrilamida/análise , Carcinógenos/análise , Cromatografia Gasosa/métodos , Cromatografia Líquida/métodos , Análise de Alimentos/métodos , Contaminação de Alimentos/análise , Acrilamida/isolamento & purificação , Carcinógenos/isolamento & purificação , Humanos
15.
J Agric Food Chem ; 62(26): 6100-7, 2014 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-24933037

RESUMO

In this paper, a rapid and effective HPLC method, using tetraazacalix[2]arene[2]triazine-modified silica gel (NCSi) as solid-phase extraction (SPE) sorbent, was developed for the purification and determination of trace acrylamide in starchy foodstuffs. The main influence factors of SPE including amount of NCSi sorbent, sample flow rate, and volume and composition of washing solution were investigated and evaluated in the sample pretreatment step. The optimized purification effect was achieved at the sample flow rate of 3 mL/min with 100 mg of NCSi and 2 mL of washing solution (water, 100%). The HPLC separation was carried out on a C18 column (250×4.6 mm i.d., 5 µm) with a mobile phase of methanol/water (10:90, v/v). The linear range of the calibration curve was 4-4000 ng/mL with s correlation coefficient of >0.9999. The intraday and interday RSDs (n=5) of peak areas of acrylamide were 0.22 and 0.90% and the intraday and interday RSDs (n=5) of retention times were 0.50 and 1.63%, respectively. In addition, overall recoveries through the extraction and NCSi-SPE purification ranged from 73.13 to 98%. Compared with the commercial SPE sorbents, NCSi featured excellent selectivity to retain polar and nonpolar interferences in the sample matrices. The improved method was simple, rapid, accurate, and promising for the determination of trace acrylamide in starchy foods with a complex matrix.


Assuntos
Acrilamida/análise , Carcinógenos/análise , Fast Foods/análise , Contaminação de Alimentos , Inspeção de Alimentos/métodos , Acrilamida/isolamento & purificação , Métodos Analíticos de Preparação de Amostras , Calixarenos/química , Carcinógenos/isolamento & purificação , China , Cromatografia Líquida de Alta Pressão , Carboidratos da Dieta/análise , Fast Foods/economia , Indicadores e Reagentes/química , Reação de Maillard , Sílica Gel/química , Extração em Fase Sólida , Amido/química , Triazinas/química
16.
Appl Biochem Biotechnol ; 173(5): 1135-44, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24771288

RESUMO

Acrylamide finds diverse industrial applications but is considered an environmental threat because of its neurotoxic, carcinogenic, and teratogenic effects. Certain bacteria enzymatically degrade acrylamide to acrylic acid and ammonia. The present investigation was carried out to isolate and identify an acrylamide-degrading bacterium from industrial effluent. Bacterial growth and extent of acrylamide degradation in the presence of different acrylamide concentrations, nutrients, varied range of pH, and temperature were analyzed. Among the eight acrylamide-degrading isolates, isolate BAC-6 demonstrated the highest degradation, and based upon the partial 16S rDNA sequencing, it was identified as Pseudomonas aeruginosa. P. aeruginosa BAC-6 grew over a wide range of acrylamide concentrations, but the highest degradation was recorded at 500 mg/L concentration with concomitant cell growth. Among the carbon supplements, mannitol supported the highest growth and degradation. Maximum degradation was reported at neutral pH. A mesophilic temperature range (25-40 °C) facilitated conducive bacterial growth followed by degradation. The highest degradation and bacterial growth were observed at 30 and 35 °C, respectively. Thus, it could be inferred from the present investigation that cultural conditions strongly affected the degradation potential of P. aeruginosa BAC-6 and advocated the utilization of the isolate in bioremediation of sites polluted with acrylamide.


Assuntos
Acrilamida/metabolismo , Poluentes Ambientais/metabolismo , Resíduos Industriais , Pseudomonas aeruginosa/isolamento & purificação , Pseudomonas aeruginosa/metabolismo , Acrilamida/isolamento & purificação , Biodegradação Ambiental , Carbono/metabolismo , Técnicas de Cultura , Poluentes Ambientais/isolamento & purificação , Concentração de Íons de Hidrogênio , Pseudomonas aeruginosa/genética , Pseudomonas aeruginosa/crescimento & desenvolvimento , Temperatura
17.
Crit Rev Food Sci Nutr ; 54(6): 708-33, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24345045

RESUMO

This review aims at summarizing the most recent updates in the field of acrylamide (AA) formation (mechanism, conditions) and the determination of AA in a number of foods (fried or baked potatoes, chips, coffee, bread, etc). The methods applied for AA detection [Capillary Electrophoresis-Mass Spectrometry (CE-MS), Liquid Chromatography-Mass Spectrometry (LC-MS), Non-Aqueous Capillary Electrophoresis (NACE), High Performance Liquid Chromatography-Mass Spectrometry (HPLC-MS), Pressurized Fluid Extraction (PFE), Matrix Solid-Phase Dispersion (MSPD), Gas Chromatography-Mass Spectrometry (GC-MS), Solid-Phase MicroExtraction-Gas Chromatography (SPME-GC), Enzyme Linked Immunosorbent Assay (ELISA), and MicroEmulsion ElectroKinetic Chromatography (MEEKC) are presented and commented. Several informative figures and tables are included to show the effect of conditions (temperature, time) on the AA formation. A section is also included related to AA legislation in EU and US.


Assuntos
Acrilamida/química , Acrilamida/isolamento & purificação , Contaminação de Alimentos/análise , Legislação sobre Alimentos/normas , Acrilamida/toxicidade , Cromatografia Líquida de Alta Pressão , Inocuidade dos Alimentos , Cromatografia Gasosa-Espectrometria de Massas
18.
Anal Chim Acta ; 760: 93-9, 2013 Jan 14.
Artigo em Inglês | MEDLINE | ID: mdl-23265738

RESUMO

Both 3-monochloropropane-1,2-diol (3-MCPD) and acrylamide are contaminants found in heat-processed foods and their related products. A quantitative method was developed for the simultaneous determination of both contaminants in food by gas chromatography-triple quadrupole mass spectrometry (GC-MS/MS). The analytes were purified and extracted by the matrix solid-phase dispersion extraction (MSPDE) technique with Extrelut NT. A coupled column (a 3 m Innowax combined with a 30 m DB-5 ms) was developed to separate both compounds efficiently without derivatization. Triple quadrupole mass spectrometry in multiple reaction monitoring mode (MRM) was applied to suppress matrix interference and obtain good sensitivity in the determination of both analytes. The limit of detection (LOD) in the sample matrix was 5 µg kg(-1) for 3-MCPD or acrylamide. The average recoveries for 3-MCPD and acrylamide in different food matrices were 90.5-107% and 81.9-95.7%, respectively, with the intraday relative standard deviations (RSDs) of 5.6-13.5% and 5.3-13.4%, respectively. The interday RSDs were 6.1-12.6% for 3-MCPD and were 5.0-12.8% for acrylamide. Both contaminants were found in samples of bread, fried chips, fried instant noodles, soy sauce, and instant noodle flavoring. Neither 3-MCPD nor acrylamide was detected in the samples of dairy products (solid or liquid samples) and non-fried instant noodles.


Assuntos
Acrilamida/análise , Contaminação de Alimentos/análise , Cromatografia Gasosa-Espectrometria de Massas , Glicerol/análogos & derivados , Acrilamida/isolamento & purificação , Animais , Bovinos , Laticínios/análise , Fast Foods/análise , Aromatizantes/análise , Glicerol/análise , Glicerol/isolamento & purificação , Leite/química , Alimentos de Soja/análise , alfa-Cloridrina
19.
J Chromatogr A ; 1218(15): 1983-7, 2011 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-21241990

RESUMO

We report the first development of a novel, planar, microfluidic, graphitic carbon separations column utilizing an array of graphitic micropillars of diamond cross-section as the chromatographic stationary phase. 795 nm femtosecond laser ablation was employed to subtractively machine fluidic architectures and a micropillared array in a planar, graphitic substrate as a monolithic structure. A sample injector was integrated on-chip, together with fluid-flow distribution architectures to minimize band-broadening and ensure sample equi-distribution across the micro-pillared column width. The separations chip was interfaced directly to the ESI probe of a Thermofisher Surveyor mass spectrometer, enabling the detection of test-mixture analytes following their differential retention on the micro-pillared graphitic column, thus demonstrating the exciting potential of this novel separations format. Importantly, unlike porous, graphitic microspheres, the temperature and pressure resilience of the microfluidic device potentially enables use in subcritical H(2)O chromatography.


Assuntos
Cromatografia Líquida de Alta Pressão/instrumentação , Grafite/química , Acrilamida/isolamento & purificação , Cromatografia Líquida de Alta Pressão/métodos , Hidrocortisona/isolamento & purificação , Técnicas Analíticas Microfluídicas , Espectrometria de Massas por Ionização por Electrospray
20.
Ars pharm ; 51(supl.3): 135-143, jul. 2010. tab
Artigo em Espanhol | IBECS | ID: ibc-99471

RESUMO

Una de las modificaciones más importantes inducidas en el alimento durante el calentamiento es la reacción de Maillard, donde participan aminoácidos y azúcares reductores, pudiendo producirse mejora de las características organolépticas del alimento pero también pérdida del valor nutritivo y aparición de compuestos tóxicos. Los cereales infantiles son hidrolizados durante el procesado, aumentando los niveles de azúcares reductores, por lo que en el tostado o desecado de estas muestras puede favorecerse el desarrollo de la reacción de Maillard. Los niños son especialmente susceptibles ala disminución del valor nutritivo y al consumo de compuestos potencialmente tóxicos, de ahí la importancia de conocer el grado de desarrollo de esta reacción en dichos productos. En este estudio se determinó el contenido de acrilamida y furosina en harinas crudas y tostadas y en papillas infantiles, con el fin de evaluar la extensión de la reacción de Maillard. El contenido de furosina osciló entre11,5-34,6 mg/100 g de proteínas en las muestras de harinas y entre 122-1193 mg/100 g de proteínas en las muestras de papillas. No se detectó acrilamida en las muestras de harinas y osciló entre 0,22 y 9,6Cg/kg en las papillas. Las pérdidas de lisina pueden considerarse altas en algunas muestras, pero no suponen riesgo de déficit nutricional al consumirse estos productos con leche. La acrilamida sólo se encontró en niveles cuantificables en cuatro muestras y en concentraciones muy bajas; éstas se encuentran lejos de la dosis máxima permitida y por lo tanto no deberían representar problemas adversos tras su consumo(AU)


One of the most important modifications originated in foods during thermal treatment is Maillard reaction, in which amino acids and reducing sugars are participants. This reaction can improve the organoleptic characteristics of foods but, moreover, can lead to nutritional value losses and apparition of toxicological compounds. Infant cereals are hydrolyzed during processing, increasing reducing sugar levels thereby Maillard reaction can be favored in toasted or dried samples. Infants are especially susceptible to the decreased nutritional value and to the toxicological compounds consumption. Thus it is important to know the development rate of this reaction in these products. In this study acrylamide and furosine content in raw and toasted flour and in infant formulas were determined, in order to evaluate Maillard reaction evolution. Furosine content ranged from 11.5 to34.6 mg/100 g of proteins in toasted flour samples and from 122 to 1193 mg/100 g of proteins in formula samples. Acrylamide was not detected in flour samples ranging from 0.22 and 9.6 Cg/kg in formula samples. Lysine losses can be considered to be high in several samples, but it does not suppose a nutritional deficiency risk because these products are consumed together with milk. Acrylamide only was found in quantified levels in four samples and in very low concentrations. These values are lower than the maximum dose allowed and, therefore, they should not represent adverse problems after their consumption(AU)


Assuntos
Humanos , Masculino , Feminino , Lactente , Pré-Escolar , Reação de Maillard , Reação de Maillard/efeitos da radiação , Aminoácidos/antagonistas & inibidores , Aminoácidos/síntese química , Aminoácidos , Grão Comestível , Grão Comestível/efeitos da radiação , Acrilamida/isolamento & purificação , Acrilamida/metabolismo , Substâncias Redutoras/metabolismo , Substâncias Redutoras/farmacologia , Substâncias Redutoras/farmacocinética
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