Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 12 de 12
Filtrar
Mais filtros

Base de dados
Tipo de documento
Intervalo de ano de publicação
1.
Anal Methods ; 16(25): 4124-4135, 2024 Jun 27.
Artigo em Inglês | MEDLINE | ID: mdl-38860427

RESUMO

This paper describes an extensive study in which a multiclass QuEChERS based approach was optimized for determination of 150 pesticides and 7 mycotoxins in table olives. Three versions of QuEChERS were evaluated and compared (unbuffered, citrate and acetate buffering). A combination of EMR-Lipid cartridges and liquid nitrogen or freezer freezing out were tested for clean-up of the oily olive extracts. Analysis of the extracts were performed by LC-MS/MS triple quadrupole. The best results were achieved using acetate QuEChERS with liquid nitrogen for clean-up. For validation, organic olives were ground and spiked at 4 concentrations with pesticides and mycotoxins (n = 5). The linearity of the calibration curves was assessed by analyzing calibration standards of 7 concentrations which were prepared separately in acetonitrile and in blank olive extract (n = 5). The validation study demonstrated that the calculated r2 was ≥0.99 for 144 pesticides and 6 mycotoxins, when the calibration curves were prepared in matrix extract, showing satisfactory linearity. Matrix effects were within the range of ±20% for only 46 pesticides and one mycotoxin. Then, to ensure reliable quantification, calibration standards had to be matrix-matched. In accuracy experiments 138 pesticides and 6 mycotoxins presented recoveries from 70 to 120% and RSD ≤ 20% for at least 2 of the 4 spike concentrations evaluated, being successfully validated. The integrated QuEChERS and LC-MS/MS method meet MRL for 11 of the 21 pesticides regulated for olives in Brazil and for 132 pesticides which are regulated in the EU law. Eleven commercial table olive samples were analyzed and 4 of them tested positive for pesticides. All the positive samples violate the Brazilian law and one sample violates also the European law.


Assuntos
Micotoxinas , Olea , Praguicidas , Espectrometria de Massas em Tandem , Olea/química , Brasil , Micotoxinas/análise , Espectrometria de Massas em Tandem/métodos , Praguicidas/análise , Cromatografia Líquida/métodos , Contaminação de Alimentos/análise , Reprodutibilidade dos Testes
2.
J Food Sci Technol ; 61(7): 1215-1237, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38910923

RESUMO

Protein has become an increasingly valuable food component with high global demand. Consequently, unconventional sources, such as industrial and agroindustrial wastes and by-products, emerge as interesting alternatives to meet this demand, considering the UN Sustainable Development Goals and the transition to a circular economy. In this context, this work presents a review of the use of Steam Explosion (SE), a green technique that can be employed as a pretreatment for various waste materials, including bones, hide/leather, feathers, and wool, aimming the extraction of protein compounds, such as low molecular weight biopeptides, gelatin, and keratin, as well as to enhance the protein functionality of grains and meals. The SE technique and the main factors affecting the process's efficiency were detailed. Promising experimental studies are discussed, along with the mechanisms responsible for protein extraction and functionality improvement, as well as the main reported and suggested applications. In general, steam explosion favored yields in subsequent extraction processes, ranging from 27 to 95%, in addition to enhancing solubility and functional protein properties. Nonetheless, it is crucial to maintain the continuity of research on this topic to drive advancements in ensuring the safety of the extracted compounds for use in consumable products and oral ingestion.

3.
Food Res Int ; 162(Pt B): 112114, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36461410

RESUMO

Gelatin is the product resulting from collagen denaturation, which, in addition to conventional sources of extraction, can be recovered from wastes and byproducts rich in collagen widely generated by the industrial activities of poultry and cattle slaughterhouses and the fishing industry. Given the properties of good film-forming ability, nontoxicity, and biocompatibility for the addition of other compounds to obtain composite materials, gelatin is a potential polymer for the production of biodegradable films and, if extracted from waste sources, can contribute to the reduction of environmental pollution and positively impact several of the Sustainable Development Goals from the United Nations Organization. The gelatins extracted from porcine, poultry, and fish skins and untanned bovine hide wastes, or by-products can be used for the production of packaging films or edible coatings, while chromium-tanned leather wastes can be applied with mulching films in agriculture aiming at greater crop yield for food production. Also, the crosslinking of gelatin protein chains and the addition of plasticizers and other additives have shown promising results in improving gelatin films' mechanical, barrier, and solubility properties. In this sense, this paper reviewed gelatin-based films from wastes, covering the main characteristics of gelatin, techniques for film production and characterization, and applications of obtained films for the food field, in addition to considerations about social, environmental, and economic aspects.


Assuntos
Filmes Comestíveis , Gelatina , Animais , Bovinos , Suínos , Conservação de Alimentos , Agricultura
4.
Food Chem ; 394: 133513, 2022 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-35749875

RESUMO

This work presents an easy and quick miniaturized procedure for the analysis of dithiocarbamates fungicides (DTC), by GC-MS, in yerba mate, an important product in South America. The sample amount, the volume of extracting solvent and acid solution, and the time of hot bath shaking were minimized. A clean-up procedure based on PSA, GCB and MgSO4 was studied in order to improve analytical signal and reduce GC-MS system damage. Blank yerba mate samples were spiked with thiram at equivalent CS2 concentrations of 0.1, 0.3, 0.5 and 1 mg kg-1. The validated method at least 2 times faster than the traditional method and was according to the latest European guidelines for pesticide residue analysis. Linearity, limits of detection and quantification, matrix effects, trueness and precision were assessed. Sixty-five commercialized samples from southern Brazil and Argentina were analyzed; 14% of samples presented CS2 concentration greater than LOQ (0.1 mg kg-1).


Assuntos
Ilex paraguariensis , Resíduos de Praguicidas , Argentina , Brasil , Cromatografia Gasosa-Espectrometria de Massas , Ilex paraguariensis/química
5.
J Agric Food Chem ; 69(38): 11440-11450, 2021 Sep 29.
Artigo em Inglês | MEDLINE | ID: mdl-34520209

RESUMO

Two simple and low-cost QuEChERS approaches were optimized and validated for multimycotoxin determination in grains by UPLC-MS/MS and applied to assess effectiveness of controlled atmosphere (CA) storage in preventing mycotoxin contamination. Common bean, soybean, and maize samples were stored for 6 months. CA treatments were conducted varying O2 and CO2 partial pressures, temperatures, and moisture contents of the chambers. In the validation study for common bean and maize, 8 out of 11 mycotoxins were successfully validated. For soybean, 10 out of 11 mycotoxins were validated. Aflatoxin B1 was detected in all commodities. Statistical tests suggest that storage temperature played a key role in aflatoxin B1 concentrations in common bean and soybean, but had no influence on maize. Maize was also positive for fumonisins B1 and B2. Differences in fumonisin concentrations were not significant among different treatments. Concentrations of aflatoxin B1 in some samples exceeded legislation's maximum levels. Thus, some of the CA treatments applied were effective in preventing mycotoxin contamination in common bean and soybean but were not effective for maize.


Assuntos
Micotoxinas , Atmosfera , Cromatografia Líquida , Contaminação de Alimentos/análise , Micotoxinas/análise , Espectrometria de Massas em Tandem
6.
J Agric Food Chem ; 69(38): 11485-11493, 2021 Sep 29.
Artigo em Inglês | MEDLINE | ID: mdl-34547203

RESUMO

Food matrices consist of many components with different physical and chemical properties that may influence instrumental robustness. The soybean contains fatty coextractives which may have a deleterious effect on the gas chromatography (GC) system. In this study, the efficiencies of PSA, C18OH, C18, silica, aluminum oxide, and Florisil, as dSPE clean-up sorbents, were evaluated by the high-performance liquid chromatography (HPLC) diode-array detector and evaporative light-scattering detector analysis. The dithiocarbamates in soybean samples are determined as CS2 using acidic hydrolysis and isooctane partitioning, followed by GC-PFPD and GC-ITD-MS analyses. The linearity of the analytical curves, the instrument limit of detection matrix effects, the trueness and precision, and the method limit of quantification (LOQ) were assessed in the validation study. Milled soybean was spiked with thiram solution at three concentration levels (corresponding to 0.05, 0.1, and 0.5 mg CS2 kg-1) for recovery determination. Silica appeared to be an effective and cheap sorbent to remove coextracted matrix components without causing any CS2 losses. Recoveries were in the range of 68-91%, with relative standard deviations ≤ 8.7%. The method LOQ was 0.05 mg CS2 kg-1, and both GC-ITD-MS and GC-PFPD systems appeared to be appropriate and complementary to determine dithiocarbamate residues in soybean extracts.


Assuntos
Fungicidas Industriais , Resíduos de Praguicidas , Cromatografia Gasosa , Cromatografia Líquida de Alta Pressão , Resíduos de Praguicidas/análise , Extração em Fase Sólida , Glycine max
7.
Food Addit Contam Part B Surveill ; 14(2): 151-161, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-34114946

RESUMO

The goal of this survey was to evaluate the presence and concentration as well as the co-occurrence of legislated and non-legislated mycotoxins in wheat flour samples from Brazil. A total of 200 wheat flour samples were analysed by a validated multi-mycotoxins method. DON was the mycotoxin with the highest occurrence, being present in 100% of the analysed samples and showing contamination in both years and regions (53-2905 µg kg-1). ZEN was detected in 51% (

Assuntos
Micotoxinas , Tricotecenos , Brasil , Farinha/análise , Contaminação de Alimentos/análise , Micotoxinas/análise , Tricotecenos/análise , Triticum
8.
Nat Prod Res ; 35(23): 5317-5322, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32363928

RESUMO

Ruellia angustiflora (Acanthaceae) is known as flower-of-fire, and its leaves are traditionally employed to promote wound healing. This study was aimed at extracting and characterizing the chemical constituents of the extracts of R. angustiflora obtained by ultrasound-assisted and supercritical fluid extractions, and subsequently investigate their antioxidant potential and cyto-genotoxicity. The extract obtained by ultrasound (UAE-EtOH) was characterized by ultraperformance liquid chromatography-mass spectrometer (UPLC-MS), and the extract obtained via supercritical fluid (SFE-CO2) by gas chromatograph-mass spectrometer (GC-MS). The antioxidant potential was verified by the antiradical activity against the 1,1-diphenyl-2-picrylhydrazyl radical (DPPH), and the cyto-genotoxicity evaluation to test cell viability and DNA damage was performed in peripheral blood mononuclear cells (PBMC) cultures. The SFE-CO2 extract presented some fatty acids, triterpenes, tetraterpenes, tocopherols and phytosterols. The UAE-EtOH extract contained phenolic acids and flavonoids, and showed the highest antioxidant capacity. Neither extract was genotoxic or cytotoxic at the tested concentrations.


Assuntos
Acanthaceae , Antioxidantes , Antioxidantes/farmacologia , Cromatografia Líquida , Dano ao DNA , Leucócitos Mononucleares , Extratos Vegetais/farmacologia , Espectrometria de Massas em Tandem
9.
Food Chem Toxicol ; 143: 111572, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32673632

RESUMO

A probabilistic dietary risk assessment on mycotoxins was conducted using the Monte Carlo Risk Assessment software, with consumption data from the 2008/2009 Brazilian Household Budget Survey for individuals who were at least 10 years old and occurrence data for 646 samples of rice, maize, wheat, and their products, collected in the Federal District and in the state of Rio Grande do Sul, Brazil. Processing factors were estimated and applied to concentration data. Chronic exposure was estimated for fumonisins (free and bound/hidden), deoxynivalenol (DON) (including the acetylated forms) and zearalenone (ZON) (including alfa-zearalenol) and acute exposure was estimated for DON. For the general population, the chronic exposure exceeded the safe exposure levels at the 95P for DON and at the 99P for fumonisins. Additionally, safe level exceedance occurred at the 97.5P for fumonisins and at the 95P for DON for teenagers, as well as at the 99P for fumonisins for women of child-bearing-age. No exceedances were found for chronic exposure to ZON and acute exposure to DON. Maize couscous contributed most of the total fumonisins (91%) and ZON intakes (~40%) and bread to total intake of DON (~30%). Further studies should be conducted with updated Brazilian consumption data, which should include information for individuals aged less than 10 years old.


Assuntos
Dieta , Grão Comestível/química , Análise de Alimentos , Contaminação de Alimentos , Micotoxinas/química , Brasil , Humanos , Medição de Risco
10.
Food Sci Biotechnol ; 28(3): 931-937, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31093452

RESUMO

ABSTRACT: The aim of this study was to evaluate the mycotoxicological quality of wheat flours used by bakeries from the North Region in Rio Grande do Sul state, Brazil, regarding the presence of mycotoxins. On collecting type-1 refined wheat flour, a conglomerate sampling from 13 cities and 3 bakeries per city (n = 39), selected from the defined region was performed. The mycotoxins analysis was using QuEChERS method and UPLC-MS/MS analysis. As a result, 100% of samples presented contamination by DON, with concentrations ranging from 76.7 to 3630.2 µg kg-1 and ZON was found in one sample (26.7 µg kg-1), which represented 2.6% of the analyzed wheat flours. Other mycotoxins (AFB1, AFB2, AFG1, AFG2, DAS, HT-2 toxin, OTA, FB1 and FB2) were not detected in the analyzed samples.

11.
Anal Chim Acta ; 1004: 40-50, 2018 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-29329707

RESUMO

This paper describes the optimization and validation of an acetonitrile based method for simultaneous extraction of multiple pesticides and mycotoxins from raw coffee beans followed by LC-ESI-MS/MS determination. Before extraction, the raw coffee samples were milled and then slurried with water. The slurried samples were spiked with two separate standard solutions, one containing 131 pesticides and a second with 35 mycotoxins, which were divided into 3 groups of different relative concentration levels. Optimization of the QuEChERS approach included performance tests with acetonitrile acidified with acetic acid or formic acid, with or without buffer and with or without clean-up of the extracts before LC-ESI-MS/MS analysis. For the clean-up step, seven d-SPE sorbents and their various mixtures were evaluated. After method optimization a complete validation study was carried out to ensure adequate performance of the extraction and chromatographic methods. The samples were spiked at 3 concentrations levels with both mycotoxins and pesticides (with 6 replicates at each level, n = 6) and then submitted to the extraction procedure. Before LC-ESI-MS/MS analysis, the acetonitrile extracts were diluted 2-fold with methanol, in order to improve the chromatographic performance of the early-eluting polar analytes. Calibration standard solutions were prepared in organic solvent and in blank coffee extract at 7 concentration levels and analyzed 6 times each. The method was assessed for accuracy (recovery %), precision (RSD%), selectivity, linearity (r2), limit of quantification (LOQ) and matrix effects (%).


Assuntos
Café/química , Micotoxinas/análise , Praguicidas/análise , Cromatografia Líquida , Espectrometria de Massas em Tandem
12.
Talanta ; 134: 415-424, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25618688

RESUMO

In this study, a very sensitive method was validated to determine pesticides residues in fruit jams using micro flow liquid chromatography-tandem mass spectrometry (µLC-MS/MS). A slurry of the fruit jams and water was prepared to yield homogeneous samples. Because of the high sensitivity achieved with the µLC-MS/MS equipment and to minimize matrix effects, the QuEChERS extracts were diluted 30-fold before the analysis. The validation was performed analyzing spiked samples at 9 and 45 µg kg(-1) (n=5). The method met validation criteria of 70-120% recovery and RSD≤20% for 92% of the 107 pesticides evaluated. The reporting limit (RL) was 9 and 45 µg kg(-1) for respectively 66% and 26% of the analytes, 5% of the compounds did not fulfill the requirements for validation and 3% were not detected at the studied concentrations. The validated method was applied to the analysis of 51 different fruit jam samples from Brazil and Spain and pesticide residues were detected in 41 samples, 26 of which contained at least one pesticide at concentration >10 µg kg(-1).


Assuntos
Contaminação de Alimentos/análise , Alimentos em Conserva/análise , Frutas , Resíduos de Praguicidas/análise , Cromatografia Líquida/métodos , Reprodutibilidade dos Testes , Espectrometria de Massas em Tandem/métodos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA