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1.
Rapid Commun Mass Spectrom ; 37(11): e9507, 2023 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-36951453

RESUMO

Liquid chromatography-tandem mass spectrometry (LC-MS/MS) is a widespread technology used for the quantitative determination of per- and polyfluoroalkyl substances (PFAS) in foodstuff. Specifically, LC-MS/MS offers an attractive performance by combining the sensitivity and selectivity required by the European Union for testing perfluorooctane sulfonic acid, perfluorooctanoic acid, perfluorononanoic acid, and perfluorohexane sulfonic acid with maximum limits of quantification (LOQ) in the sub-parts-per-billion (µg/kg) or the parts-per-trillion (ng/kg) domains. In this article, we highlight the important diversity in LOQ definitions applied in LC-MS/MS methods described in the literature that raise concerns about the capability of some of those to generate reliable data requested by the European regulation. Here, we point out the risk of false response or misquantification if the criteria for assessing LOQ suffer from a lack of rigor. We emphasize the need to use PFAS-free samples spiked with the analyte(s) of interest and the application of identification criteria according to official documents for a sound measurement of the LOQ.


Assuntos
Fluorocarbonos , Espectrometria de Massas em Tandem , Cromatografia Líquida , Espectrometria de Massas em Tandem/métodos , Reprodutibilidade dos Testes , Fluorocarbonos/análise , Cromatografia Líquida de Alta Pressão/métodos
2.
Crit Rev Food Sci Nutr ; : 1-9, 2022 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-35852101

RESUMO

After nearly two decades since acrylamide was first raised as a potential safety issue in foods, significant progress has been made in understanding its formation during cooking, how to reduce levels in the most concerned foods, and the possible cancer risk to humans. Despite the huge wealth of knowledge gathered on this topic over the past years, a few new discoveries in occurrence, mitigation, analysis and risk assessment are worthy to note. This short review highlights the salient novelties pertaining to acrylamide, particularly in the areas of formation & analysis, existing and possible future regulations in the European Union, and finally considerations that may lead to possibly revisiting the toxicity of acrylamide and the main metabolite, glycidamide.

3.
Artigo em Inglês | MEDLINE | ID: mdl-38170576

RESUMO

A call for data on the occurrence of alkylfurans in food and feed from EFSA triggered the development of new methods to cover next to furan also 2- and 3-methylfuran, 2,5-dimethyl- and 2-ethylfuran as well as 2-pentylfuran. A significant variability was noticed when comparing analysis of 2-pentylfuran and furans in the same matrix performed by different laboratories. To assess the variability an interlaboratory study including eight laboratories was organised. The highest variabilities were observed when analysing cereals, with measurements of 2-pentylfuran indicating concentrations from 8 mg/kg up to more than 1000 mg/kg in the same sample. This study illustrates that the analysis of 2-pentylfuran requires special attention, and that additional method development would be necessary to ensure reliable and reproducible determination of 2-pentylfuran at contamination level. Moreover, a recent evaluation of the EFSA Panel on Food Additives and Flavourings indicates that concerns for genotoxicity, reason why it was grouped with the shorter alkylfurans, are now ruled out. We question the need and justification to include 2-pentylfuran in the analytical method as requested by EFSA, from both the analytical and the safety perspective.


Assuntos
Grão Comestível , Furanos , Cromatografia Gasosa-Espectrometria de Massas/métodos , Furanos/análise , Grão Comestível/química
4.
J AOAC Int ; 107(3): 453-463, 2024 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-38273660

RESUMO

BACKGROUND: Acrylamide (AA) is a process contaminant naturally formed during the cooking of starchy food at high temperatures. Considering existing risks of misquantification inherent to the analysis of AA, an AOAC initiative raised the need for a consensus standard to determine AA in a broad variety of food. OBJECTIVE: A quantitative LC-MS/MS method for AA determination in food was validated in a single-laboratory study. Targeted performance requirements in terms of target matrixes, limit of quantification, recovery, and precision were as defined per Standard Method Performance Requirement (SMPR®) 2022.006. METHOD: The proposed method derives from EN 16618:2015 standard pending modifications brought to the (1) sample preparation (simplified, potentially automated); (2) scope of application (significantly extended); and (3) LC conditions (improved selectivity). Confirmatory detection of AA is conducted by LC-MS/MS in the Selected Reaction Monitoring mode (SRM), and isotopic dilution was applied for quantification approach using either 2,3,3-d3-acrylamide (d3-AA), or 13C3-2,3,3-d3-acrylamide (13C3-d3-AA) as labeled internal standard. RESULTS: A total of 16 laboratory samples from nine matrix categories were included in the validation process. A full validation was conducted on coffee (instant, roast), infant cereal, cocoa powder, pet food (croquettes), tea (green tea), spices (black pepper), and nuts (roasted almonds) with satisfactory performances both in terms of recovery (97-108%) and precision (RSDr and RSDiR <12%). The method applicability was further demonstrated through the analysis of quality control materials and reference materials including French fries, potato crisps, vegetable crisps, instant coffee, infant food, and biscuits (cookies), with accuracy values determined within a 94-107% range. CONCLUSIONS: The performances of the presented method are in agreement with the acceptance criteria stipulated in SMPR 2022.006. HIGHLIGHTS: The Expert Review Panel for acrylamide approved the present method as AOAC Official First Action 2023.01.


Assuntos
Acrilamida , Cacau , Café , Grão Comestível , Contaminação de Alimentos , Alimentos Infantis , Nozes , Solanum tuberosum , Espectrometria de Massas em Tandem , Chá , Acrilamida/análise , Espectrometria de Massas em Tandem/métodos , Chá/química , Café/química , Cromatografia Líquida/métodos , Solanum tuberosum/química , Grão Comestível/química , Contaminação de Alimentos/análise , Nozes/química , Cacau/química , Alimentos Infantis/análise , Especiarias/análise , Análise de Alimentos/métodos , Chocolate/análise , Verduras/química , Animais , Ração Animal/análise , Espectrometria de Massa com Cromatografia Líquida
5.
J AOAC Int ; 107(4): 617-631, 2024 Jul 04.
Artigo em Inglês | MEDLINE | ID: mdl-38627236

RESUMO

BACKGROUND: The presence of veterinary drug residues in food-producing animals and animal products is regulated through the enforcement of maximum residue limits (MRLs). To answer the need of the food sector to monitor these substances in a wide range of food commodities, stakeholders at AOAC INTERNATIONAL identified the need for a reliable confirmatory screening method. Such a qualitative approach is required for compliance checking and to support product release in manufacturing. OBJECTIVE: Data were collected from five independent laboratories that applied the First Action Official Method 2020.04 to demonstrate adequate performance under reproducibility conditions. The probability of detection (POD) was calculated in blank test samples and test samples spiked at the screening target concentration (STC) level, with the objective to achieve PODs ≤10% and ≥90%, respectively. Additionally, the effectiveness of the screening method was evaluated by participating in 92 proficiency tests. METHODS: Four streams were optimized to screen for 152 veterinary drug residues by LC-MS/MS in a wide variety of food commodities including milk-based ingredients and related products (e.g., milk fractions, infant formula, infant cereals, and baby foods), meat- and fish-based ingredients and related products (fresh, powdered, cooked, infant cereals, and baby foods), and other ingredients based on eggs, animal fat, and animal byproducts. The four streams covered 105 antibiotic residues, anti-inflammatory and antiparasitic agents (stream A), 23 beta-lactams (stream B), 14 aminoglycosides (stream C), and 10 tetracyclines (Stream D). RESULTS: The multilaboratory validation led to PODs at the STC ≥94% and PODs in the blank ≤9%. Further application of the multilaboratory validated method to 92 proficiency tests provided more than 99% satisfactory submitted results (n = 784). CONCLUSION: The interlaboratory reproducibility determined for this method met the acceptance criteria defined in AOAC Standard Method Performance Requirement (SMPR®) 2018.010. HIGHLIGHTS: AOAC has approved the method for Final Action status.


Assuntos
Resíduos de Drogas , Contaminação de Alimentos , Espectrometria de Massas em Tandem , Drogas Veterinárias , Resíduos de Drogas/análise , Drogas Veterinárias/análise , Espectrometria de Massas em Tandem/métodos , Animais , Contaminação de Alimentos/análise , Cromatografia Líquida/métodos , Leite/química , Reprodutibilidade dos Testes , Carne/análise , Análise de Alimentos/métodos , Espectrometria de Massa com Cromatografia Líquida
6.
Food Chem ; 403: 134355, 2023 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-36183468

RESUMO

Robusta and Arabica green beans were supplemented with carbon 14-glyphosate labelled on each carbon position alternatively prior to roasting, up to 220 °C for Robusta and 200 °C for Arabica (2, 5 and 10 min). The results of the study point a significant decomposition of glyphosate that happens during roasting, from at least 42 % to > 74 % depending on roasting conditions (time, temperature) and coffee variety. The data obtained with 14C-labelled glyphosate materials suggest that the carboxymethyl branch of the compound degrades more effectively than the phosphonomethyl moiety. The degradation of glyphosate does not lead to the formation of aminomethylphosphonic acid (AMPA). The results of the study indicate that carbon dioxide, methylamine and dimethylamine are major degradation products of glyphosate formed along coffee roasting, likely released with the roasting gas. Ultimately, the results of the study show that levels of glyphosate in green beans do not mirror those in coffee beverages.


Assuntos
Coffea , Coffea/química , Sementes/química , Temperatura Alta , Radioisótopos de Carbono , Glifosato
7.
Artigo em Inglês | MEDLINE | ID: mdl-37410932

RESUMO

To enable the monitoring of a wide scope of per- and polyfluoroalkyl substances (PFAS) in the ng/kg level in foodstuffs, an LC-MS/MS method comprising 57 analytes was developed and validated in seven different matrices (milk powder, milk-based infant formula, meat-based baby food puree, fish and fish oil, fresh egg, and soluble coffee). The analytical approach was based on an acetonitrile:water extraction followed by solid phase extraction clean-up with subsequent quantification of the extracted analytes either by isotope dilution (55 compounds) or by standard addition (2 compounds) mass spectrometry. The validation criteria followed the guidance document for the analysis of PFAS issued by the European Union Reference Laboratory for Halogenated Persistent Organic Pollutants. The lowest limits of quantification (LOQs) for the four recently regulated compounds (L-PFOS, PFOA, PFNA, L-PFHxS) were set at 0.010 µg/kg in baby and infant foods (as sold) but also in dairy ingredients. Exception was for PFOA in milk powder due to too large variability in the repeatability. Applicability of the method was further demonstrated in 37 commodity check matrices. Overall validation data demonstrated the robustness of the method for most of the compounds and the LOQs achieved were low enough to ensure compliance with Commission Regulation EU 2022/2388 but also to support future collection of occurrence data in ng/kg level in food.


Assuntos
Fluorocarbonos , Espectrometria de Massas em Tandem , Animais , Cromatografia Líquida , Pós/análise , Leite/química , Fórmulas Infantis/análise , Fluorocarbonos/análise
8.
Artigo em Inglês | MEDLINE | ID: mdl-36395391

RESUMO

This study describes the extension of a gas chromatography mass spectrometry (GC-MS) method, initially devoted to the analysis of ethylene oxide (EO) in ice cream, to a larger range of food items including herbs, spices, vegetables, inorganic salts, food supplements, thickeners, etc. Results are reported as EOTotal according to EC 2015/868 definition (expressed as EO equivalents as the sum of native EO and 2-chloroethanol (2-CE) after acidic hydrolysis) with a limit of quantification at 0.01 mg/kg regardless of the food item. Its ruggedness was demonstrated through fortification experiments on hundreds of samples. Re-analysis of 146 positive food samples without hydrolysis demonstrated that not EO but 2-CE is the predominant analyte detected in the different processed ingredients suspected to have been previously treated with EO. A series of eight contaminated dried herbs and spices were also re-analysed by four ISO 17025 accredited commercial laboratories making use of different analytical strategies for EO determination in foods. Each laboratory reported EOTotal levels within the same concentration range, but the resulting reproducibility ranged from 23% to 41% depending on the sample. Additionally, we show that results of free EO from methods based on conversion to 2-iodoethanol may lead to artefactual detection of native EO (false positive). An official method of analysis applicable for different food matrices would be useful to avoid discrepancies of results. Altogether, these data re-enforce the fact that in absence of native EO in food items, risk assessment of EO in foodstuffs should consider the predominance of 2-CE. A toxicological risk assessment using the food additive xanthan gum as a case study is discussed.


Assuntos
Etilenocloroidrina , Óxido de Etileno , Óxido de Etileno/análise , Reprodutibilidade dos Testes , Etilenocloroidrina/análise , Cromatografia Gasosa-Espectrometria de Massas/métodos , Medição de Risco
9.
Artigo em Inglês | MEDLINE | ID: mdl-36098978

RESUMO

Liquid chromatography-high resolution mass spectrometry (LC-HRMS) is considered an unavoidable extension of low-resolution LC-MS/MS that stretches the capabilities of multi-residue analysis of chemical contaminants in food. However, LC-HRMS acquisitions generate a massive amount of information available for data processing with supplier software that still miss critical calculation features and adapted reporting tools. Consequently, routine laboratories are still reluctant to switch from LC-MS/MS to LC-HRMS, the latter is still perceived as a cumbersome and demanding technology. In that context, we propose a four-step LC-HRMS workflow to speed-up data processing in situations of multi-residue multi-matrix analysis with the goal to maximize the time spent on data interpretation rather than on data formatting. The first three steps of the workflow imply specific settings on the Orbitrap HRMS associated software (TraceFinderTM) while the fourth step is the novelty i.e. a newly coded R-script capable to translate a raw export file into a comprehensive .xlsx report file in a few seconds. As recommended by various international guidelines and in some official methods, standard addition-based applications are fully embedded in this reporting tool whilst still being the main bottleneck of supplier's software. The reporting tool also allows appropriate data formatting, filtering, and color-coding options to provide a clear picture of compounds being detected or not, and those requiring specific attention due to unmet quality control criteria as required by European legislation (European Commission SANTE 11312/2021). It is hoped that additional functionalities compatible with R scripts will be soon fully embedded in the supplier's software for easier data interpretation and reporting.


Assuntos
Software , Espectrometria de Massas em Tandem , Cromatografia Líquida/métodos , Espectrometria de Massas em Tandem/métodos , Controle de Qualidade , Laboratórios
10.
Artigo em Inglês | MEDLINE | ID: mdl-35113763

RESUMO

Acrylamide is prone to misquantification, and critical steps in the analytical procedures need to be identified and controlled to ensure a reliable determination. Four methods were considered to illustrate misquantification issues with acrylamide. For two methods varying by the extent of their sample preparations, cases of overestimation in cocoa samples reaching up to a 20-fold factor are shown. A second example, applied to a variety of food products, includes two other methods varying by their chromatographic conditions. As a follow up of a study conducted in 2020 about the identification of N-acetyl-ß-alanine as an interference of acrylamide in coffee, the extent of this interference was evaluated in a selection of coffee samples, cereal-based products and baby foods. The ultimate objective of this manuscript was to resolve such cases of misquantification and validate a wide scope and robust method allowing an interference free acrylamide analysis. To do so, an extraction procedure based on the EN 16618:2015 standard with water extraction and two consecutive solid phase extraction (SPE) steps was applied with modified liquid chromatographic conditions. The method was validated in coffee, cereals, baby foods, cocoa and pet foods with excellent performance in terms of recovery (97-108%) and precision (RSDr and RSDiR <12 %). The breath of scope was further proved through trueness determination in quality control materials and reference materials including French fries, potato crisps, vegetable crisps, instant coffee, infant food and biscuit (cookie), with trueness values found within a 94-107% range.


Assuntos
Acrilamida , Cacau , Acrilamida/análise , Cromatografia Líquida/métodos , Café/química , Consenso , Grão Comestível/química , Contaminação de Alimentos/análise , Humanos , Espectrometria de Massas em Tandem/métodos
11.
Artigo em Inglês | MEDLINE | ID: mdl-34418759

RESUMO

Alkylfurans have been found concurrently to furan in thermally processed food and might add to the overall exposure, thereby increase the health concern. The analytical methods developed for these compounds are based on gas chromatography separation coupled to mass spectrometry. Two of those alkylfurans, 2,5-dimethylfuran and 2-ethylfuran, are isomers, for which accurate quantification require either complete chromatographic separation or tandem mass spectrometry (MS/MS) selectivity. A new chromatographic method is reported using the Supelco Equity-1 column, demonstrating complete baseline separation of these two isomers, with a shorter runtime when using single mass spectrometry. Full validation was performed successfully for furan, 2- and 3-methylfuran, 2-ethylfuran, 2,5-dimethylfuran and 2-pentylfuran on different food matrices with recovery rates in the range of 80-110 %, repeatability below 14%, intermediate reproducibility below 22% as well as expanded uncertainty under 50%.


Assuntos
Café/química , Grão Comestível/química , Furanos/análise , Cromatografia Gasosa-Espectrometria de Massas/métodos , Furanos/química , Furanos/isolamento & purificação , Humanos , Lactente , Alimentos Infantis/análise , Modelos Lineares , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Microextração em Fase Sólida/métodos
12.
Foods ; 11(1)2021 Dec 29.
Artigo em Inglês | MEDLINE | ID: mdl-35010202

RESUMO

With the rising trend of consumers being offered by start-up companies portable devices and applications for checking quality of purchased products, it appears of paramount importance to assess the reliability of miniaturized sensors embedded in such devices. Here, eight sensors were assessed for food fraud applications in skimmed milk powder. The performance was evaluated with dry- and wet-blended powders mimicking adulterated materials by addition of either ammonium sulfate, semicarbazide, or cornstarch in the range 0.5-10% of profit. The quality of the spectra was assessed for an adequate identification of the outliers prior to a deep assessment of performance for both non-targeted (soft independent modelling of class analogy, SIMCA) and targeted analyses (partial least square regression with orthogonal signal correction, OPLS). Here, we show that the sensors have generally difficulties in detecting adulterants at ca. 5% supplementation, and often fail in achieving adequate specificity and detection capability. This is a concern as they may mislead future users, particularly consumers, if they are intended to be developed for handheld devices available publicly in smartphone-based applications.

13.
J AOAC Int ; 104(3): 650-681, 2021 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-33351146

RESUMO

BACKGROUND: Veterinary drug residues in food are substances (>200 compounds) exhibiting potential health risks for consumers, thus being regulated in national legislations and the Codex Alimentarius. Most of the compounds are regulated based upon a maximum residue limit (MRL) while a few of them are banned in food for humans. The food sector needs a reliable and consensus analytical platform able to monitor these substances in a wide range of food commodities. OBJECTIVE: Several confirmatory methods based on liquid chromatography-mass spectrometry are available in the literature for either screening or quantification of veterinary drug residues in food, but usually applicable to limited scope of matrices. The current work describes the single-laboratory validation (SLV) of a method for screening 154 veterinary drug residues in several food categories. METHODS: This work describes a streamlined platform making use of liquid chromatography-tandem mass spectrometry (LC-MS/MS) for screening 105 antibiotics, 41 antiparasitics, 5anti-inflammatory agents, and 3 tranquilizers in foods of animal origin. For the best performance across the commodities (dairy-, meat-, fish-, and egg-based materials), four method streams were established. As a screening tool, probabilities of detection (PODs) were assessed at the screening target concentration (STC < MRL) and the blank. RESULTS: The SLV led to PODs at the STC >94% and PODs in the blank < 4%. CONCLUSION: Performance is in agreement with the acceptance criteria defined in SMPR 2018.010. HIGHLIGHTS: The Expert Review Panel approved the present method as AOAC Official First Action 2020.04.


Assuntos
Resíduos de Drogas , Drogas Veterinárias , Animais , Cromatografia Líquida , Resíduos de Drogas/análise , Contaminação de Alimentos/análise , Humanos , Carne/análise , Espectrometria de Massas em Tandem , Drogas Veterinárias/análise
14.
Artigo em Inglês | MEDLINE | ID: mdl-34477495

RESUMO

Residues of ethylene oxide (EO), a banned fumigant in the EU, were found at amounts above the maximum residue limit (MRL) in carob (locust) bean gum (additive E410). The pesticide entered the food chain via stabiliser blends that are used as minor ingredients in the manufacture of ice cream. Consequently, all products that contained the non-compliant ingredient were withdrawn or recalled in several countries across the EU, in most cases irrespective of whether the pesticide residue was detectable or not in the final product. This is the first report of a reliable method to determine EO and its metabolite/marker compound 2-chloroethanol (2-CE), either together or independently in ice cream, with a limit of quantification at 0.01 mg EO/kg and recovery in the range of 87-104% across the levels investigated (0.01, 0.02 and 0.06 mg EO/kg). The method applies QuEChERS extraction and isotope dilution gas chromatography coupled with tandem mass spectrometry (GC-MS/MS). High resolution mass spectrometry (HRMS) confirmed the specificity of low mass ions. Data on the stability of EO and 2-CE under thermal conditions revealed that 2-CE is relatively stable in an ice cream matrix (ca. 80% recovery of spiked material). Importantly, this study also demonstrates that not EO, but 2-CE is the predominant analyte detected in the contaminated samples, which is new information of significance in terms of the overall risk assessment of EO in foodstuffs.


Assuntos
Etilenocloroidrina/análise , Óxido de Etileno/análise , Análise de Alimentos , Contaminação de Alimentos/análise , Galactanos/química , Sorvetes/análise , Mananas/química , Gomas Vegetais/química , Cromatografia Gasosa-Espectrometria de Massas
15.
Toxicol Appl Pharmacol ; 245(1): 57-66, 2010 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-20144636

RESUMO

Estragole has been shown to be hepatocarcinogenic in rodent species at high-dose levels. Translation of these results into the likelihood of formation of DNA adducts, mutation, and ultimately cancer upon more realistic low-dose exposures remains a challenge. Recently we have developed physiologically based biokinetic (PBBK) models for rat and human predicting bioactivation of estragole. These PBBK models, however, predict only kinetic characteristics. The present study describes the extension of the PBBK model to a so-called physiologically based biodynamic (PBBD) model predicting in vivo DNA adduct formation of estragole in rat liver. This PBBD model was developed using in vitro data on DNA adduct formation in rat primary hepatocytes exposed to 1'-hydroxyestragole. The model was extended by linking the area under the curve for 1'-hydroxyestragole formation predicted by the PBBK model to the area under the curve for 1'-hydroxyestragole in the in vitro experiments. The outcome of the PBBD model revealed a linear increase in DNA adduct formation with increasing estragole doses up to 100 mg/kg bw. Although DNA adduct formation of genotoxic carcinogens is generally seen as a biomarker of exposure rather than a biomarker of response, the PBBD model now developed is one step closer to the ultimate toxic effect of estragole than the PBBK model described previously. Comparison of the PBBD model outcome to available data showed that the model adequately predicts the dose-dependent level of DNA adduct formation. The PBBD model predicts DNA adduct formation at low levels of exposure up to a dose level showing to cause cancer in rodent bioassays, providing a proof of principle for modeling a toxicodynamic in vivo endpoint on the basis of solely in vitro experimental data.


Assuntos
Anisóis/toxicidade , Carcinógenos/toxicidade , Adutos de DNA/metabolismo , Hepatócitos/efeitos dos fármacos , Modelos Biológicos , Derivados de Alilbenzenos , Animais , Anisóis/química , Anisóis/metabolismo , Hepatócitos/metabolismo , Humanos , Masculino , Testes de Mutagenicidade , Ratos , Ratos Sprague-Dawley
16.
J Chromatogr A ; 1610: 460566, 2020 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-31582163

RESUMO

Analysis of acrylamide in coffee by liquid chromatography-tandem mass spectrometry (LC-MS/MS) is prone to interferences. According to our study, unknown background ions can entail an overestimation by up to 40% in case of coelution with acrylamide. In order to develop a precise and accurate quantification method for acrylamide, identification and removal of these interfering ions is requested. We thus studied potential isobaric impurities of acrylamide using liquid chromatography-high resolution mass spectrometry (LC-HRMS). An in-source fragment of N-Acetyl-ß-alanine, a substance not yet reported in coffee, was identified as the main interfering ion. The characterization of the interference further triggered modification of the mobile phase-pH to alter the retention of N-Acetyl-ß-alanine and achieve an interference free acrylamide determination. Two other compounds closely related to acrylamide namely 3-aminopropanamide and lactamide were also susceptible to in-source fragmentation, highlighting the pivotal role of chromatographic conditions to ensure a reliable quantification of acrylamide.


Assuntos
Acrilamida/análise , Cromatografia Líquida/métodos , Café/química , Espectrometria de Massas em Tandem/métodos , Padrões de Referência , Solventes/química , beta-Alanina/análise
17.
J Agric Food Chem ; 68(29): 7727-7733, 2020 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-32578985

RESUMO

The study reports the role of choline and compounds thereof in the formation of chlormequat under thermal conditions, with emphasis on the molecular mechanism involved in the transformation. The data show the decomposition of choline to chlormequat at 200 °C in presence of chloride ions, likely by nucleophilic substitution. Furthermore, the results suggest that phosphatidylcholine, glycerophosphocholine, and phosphocholine are the effective precursors of chlormequat under sufficient thermal conditions due to their capability to degrade to choline and/or the ability of the phosphate moiety to behave as a good leaving group with respect to nucleophilic attacks. Thermal treatments (120 and 200 °C) applied to egg powder, rich in phosphatidylcholine, and wheat flour, with choline at a substantial level, suggest that less energy is required for obtaining chlormequat from phosphatidylcholine than from choline. This observation is consistent with the postulated mechanism of a nucleophilic substitution with phosphate moieties acting as better leaving groups than the hydroxyl group.


Assuntos
Clormequat/análise , Ovos/análise , Farinha/análise , Reguladores de Crescimento de Plantas/análise , Triticum/química , Animais , Galinhas , Colina/análise , Temperatura Alta
18.
Food Chem ; 320: 126601, 2020 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-32208180

RESUMO

Acrylamide (AA) formation during coffee roasting happens rapidly, reaching a peak value within the first minutes of roasting followed by a fast decrease to reach an asymptote at approximately 200 µg/kg. Today, the mechanisms by which AA is reduced during roasting remain unclear. In this research, the fate of AA during roasting followed by drip brewed-like extraction was studied using 14C-radiolabeled (14C-AA) and 13C-labeled (13C3-AA) materials. Results showed that 28% of the spiked 14C-AA was lost during the roasting process, presumably by degradation to volatile compounds and 25% was non-extractable; therefore, appeared bound to the matrix. About 50% of initial AA went into the water extract, either unchanged or transformed by conjugation/binding. The release of bound acrylamide was further evidenced by increasing levels of 13C3-AA over prolonged roasting times. In addition, the absence of 14C activity in the hexane extracts suggested acrylamide not to bind to any lipophilic material.


Assuntos
Acrilamida/química , Café/química , Manipulação de Alimentos , Acrilamida/análise , Radioisótopos de Carbono , Temperatura Alta
19.
Food Chem ; 303: 125406, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31472386

RESUMO

This study reports the heat-induced formation of furan by decarboxylation of 2-furoic acid, and 2-methylfuran by dehydration of furfuryl alcohol under dry conditions. Model systems were incubated at temperatures up to 190 °C, followed by quantitative determination of furan and 2-methylfuran performed by isotope dilution headspace gas chromatography-mass spectrometry. Results show that 2-furoic acid decarboxylation and furfuryl alcohol dehydration are activated as from about 140-160 °C. Furfuryl alcohol and 2-furoic acids were measured in a selection of roasted coffee products by isotope dilution liquid chromatography-high resolution mass spectrometry, and the data evidenced a strong correlation between the two compounds, suggesting an intimate mechanistic relationship between them. The possible oxidation of furfuryl alcohol to furfural and 2-furoic acid in heated food is raised with particular emphasis on coffee roasting. These findings are relevant for better understanding the formation of furan and alkylfurans in food, and ultimately opening avenues for mitigation.


Assuntos
Furanos/análise , Furanos/química , Coffea/química , Culinária , Contaminação de Alimentos/análise , Cromatografia Gasosa-Espectrometria de Massas/métodos , Temperatura Alta , Sementes/química
20.
Food Chem ; 295: 42-50, 2019 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-31174777

RESUMO

Mid-infrared analysis of reconstituted milk is proposed as a feasible solution for the detection of milk powder adulteration regardless of the blending practice. To challenge the concept, skim milk powders were spiked with three of the most reactive/unstable of potential milk adulterants: semicarbazide hydrochloride, ammonium sulfate and cornstarch. To create the wet-blended set, a fraction of each sample was reconstituted and re-spray dried at laboratory scale with a benchtop spray dryer. Dry and wet-blended adulterated samples were reconstituted prior to mid-infrared measurement and projected onto a one-class classifier SIMCA model for reconstituted skim milk. Quantitative sensitivities, determined from the normalized orthogonal distances, were compared. Although the non-industrial spray drying introduced a spectroscopic bias, as revealed by the control samples, the non-targeted mid-infrared model showed comparable sensitivities for both blending practices once the main bias-rich spectral regions were removed, validating thereby the proposed concept.


Assuntos
Análise de Alimentos/métodos , Contaminação de Alimentos/análise , Leite/química , Espectroscopia de Infravermelho com Transformada de Fourier/métodos , Sulfato de Amônio/química , Animais , Análise de Alimentos/economia , Modelos Teóricos , Pós/química , Semicarbazidas/química , Amido/química
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