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1.
J Chromatogr A ; 1621: 461081, 2020 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-32349863

RESUMO

The chemical composition distribution (CCD) of three single site made ethylene/1-octene copolymers was investigated through offline-hyphenation of solvent gradient interaction chromatography (SGIC) with 1H NMR. Thus, a clear, non-linear correlation between SGIC elution time and chemical composition was found under the specific measurement conditions applied here. The application of 1H NMR as detection allowed to determine the CCD with unprecedented accuracy. 2D-LC of the copolymers revealed the correlation between CCD and molar mass distribution (MMD) in a quantitative manner. Furthermore, this approach allowed a comparison between the response behavior of an evaporative light scattering detector (ELSD, semi-quantitative, commonly applied in SGIC) and that of an infrared (IR) detector (quantitative, commonly applied in SEC). As a result, it could be shown that ELSD results are close to IR results for the system investigated here, in other words, the often-criticized semi-quantitative response behavior of the ELSD is affecting results in an acceptable manner.


Assuntos
Alcenos/análise , Cromatografia Líquida de Alta Pressão/métodos , Elastômeros/análise , Etilenos/análise , Polienos/análise , Calibragem , Espectroscopia de Ressonância Magnética Nuclear de Carbono-13 , Elastômeros/química , Peso Molecular , Espectroscopia de Prótons por Ressonância Magnética , Solventes/química , Temperatura , Fatores de Tempo
2.
Artigo em Inglês | MEDLINE | ID: mdl-30601713

RESUMO

Swiss control authorities checked the safety assessment of nine major producers of polyolefin granulates for making food contact materials. It was a pilot project to gain experience on the procedure of collecting and evaluating compliance documentation, but also to obtain insight into the quality of compliance work performed by the main plastic producers. It revealed that there are fundamental problems in performing such control. These are reported with proposals for improvement. For most products, the safety assessment made available did not correspond to the requirements, as confirmed by a group of internationally recognised experts, who were asked for their opinion on whether the safety of the migrates was assessed in accordance to 'internationally accepted scientific methods on risk assessment', as required by Art. 19 of Regulation (EU) 10/2011 and specified by EFSA.


Assuntos
Contaminação de Alimentos/análise , Inocuidade dos Alimentos , Polienos/análise , Documentação , União Europeia , Embalagem de Alimentos , Humanos , Medição de Risco , Suíça
3.
J Chromatogr A ; 1402: 94-101, 2015 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-26037318

RESUMO

Multidimensional chromatography based on two-dimensional high performance liquid chromatography on-line coupled to gas chromatography (on-line HPLC-HPLC-GC) enables the separate analysis of saturated, monounsaturated and aromatic hydrocarbons in packaging materials like polyolefins or paperboard and their migrates into foods. Since normal-phase HPLC on silica gel did not preseparate saturated from monounsaturated hydrocarbons, a separation step on a normal-phase HPLC column treated in the laboratory with an optimized amount of silver nitrate was added. The preparation of this HPLC column and the instrumental set-up are described, followed by examples showing the potential of the method. In a preliminary investigation of 11 polyolefin granulates for food contact up to 40% monounsaturated hydrocarbons among the oligomers C16-35 were determined.


Assuntos
Cromatografia Gasosa , Cromatografia Líquida de Alta Pressão , Análise de Alimentos/métodos , Contaminação de Alimentos/análise , Embalagem de Alimentos , Hidrocarbonetos/análise , Hidrocarbonetos Aromáticos/análise , Polienos/análise , Sílica Gel
4.
Int J Syst Evol Microbiol ; 63(Pt 10): 3769-3776, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23645023

RESUMO

A light-yellow-coloured bacterium, designated strain PTJT-5(T), was isolated from the stem of Smilacina japonica A. Gray collected from Taibai Mountain in Shaanxi Province, north-west China, and was subjected to a taxonomic study by using a polyphasic approach. The novel isolate grew optimally at 25-28 °C and pH 6.0-7.0. Flexirubin-type pigments were produced. Cells were Gram-reaction-negative, strictly aerobic, rod-shaped and non-motile. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain PTJT-5(T) was a member of the phylum Bacteroidetes, exhibiting the highest sequence similarity to Lacibacter cauensis NJ-8(T) (87.7 %). The major cellular fatty acids were iso-C15 : 0, iso-C15 : 1 G, iso-C17 : 0 and iso-C17 : 0 3-OH. The only polyamine was homospermidine and the major polar lipid was phosphatidylethanolamine. The only respiratory quinone was MK-7 and the DNA G+C content was 40.3 mol%. Based on the phenotypic, phylogenetic and genotypic data, strain PTJT-5(T) is considered to represent a novel species of a new genus in the family Chitinophagaceae, for which the name Taibaiella smilacinae gen. nov., sp. nov. is proposed. The type strain of Taibaiella smilacinae is PTJT-5(T) ( = CCTCC AB 2013017(T) = KCTC 32316(T)). An emended description of Flavihumibacter petaseus is also proposed.


Assuntos
Bacteroidetes/classificação , Maianthemum/microbiologia , Filogenia , Técnicas de Tipagem Bacteriana , Bacteroidetes/genética , Bacteroidetes/isolamento & purificação , Composição de Bases , China , DNA Bacteriano/genética , Ácidos Graxos/análise , Dados de Sequência Molecular , Fosfatidiletanolaminas/análise , Caules de Planta/microbiologia , Polienos/análise , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Espermidina/análise , Vitamina K 2/análogos & derivados , Vitamina K 2/análise
5.
Int J Syst Evol Microbiol ; 63(Pt 9): 3494-3500, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23543504

RESUMO

Two yellow-pigmented, rod-shaped, non-motile, Gram-reaction-negative and aerobic bacterial strains, designated KYW560(T) and KYW563(T), were isolated from seawater collected from Gwangyang Bay, Republic of Korea. The isolates required sea salts for growth. Flexirubin-type pigments were absent. The common major cellular fatty acids (>5% of total) of the two strains were C(16:0), C(18:0), iso-C(15:0), anteiso-C(15:0), iso-C(15:1) G, iso-C(17:0) 3-OH and summed feature 3 (C(16:1)ω6c and/or C(16:1)ω7c). Strain KYW560(T) also contained iso-C(15:0) 3-OH and C(20:1)ω9c as major fatty acids. The main polar lipids were phosphatidylethanolamine, an unidentified aminolipid and two unidentified lipids. The predominant isoprenoid quinone was MK-6. The DNA G+C contents of strains KYW560(T) and KYW563(T) were 41.0 ± 0.7 and 38.3 ± 0.4 mol% (mean ± sd of three determinations), respectively. Phylogenetic analysis based on 16S rRNA gene sequences indicated that the isolates belonged to the family Flavobacteriaceae, and were related to the genus Algibacter. Based on data from this taxonomic study using a polyphasic approach, it is proposed that the isolates represent novel species of the genus Algibacter, for which the names Algibacter agarivorans sp. nov. (type strain, KYW560(T) =KCTC 23855(T) =JCM 18285(T)) and Algibacter agarilyticus sp. nov. (type strain, KYW563(T) =KCTC 23857(T) =JCM 18275(T)) are proposed. Reclassification of Marinivirga aestuarii as Algibacter aestuarii comb. nov. and emended description of the genus Algibacter are also proposed.


Assuntos
Flavobacteriaceae/classificação , Filogenia , Água do Mar/microbiologia , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , Ácidos Graxos/análise , Flavobacteriaceae/genética , Flavobacteriaceae/isolamento & purificação , Dados de Sequência Molecular , Hibridização de Ácido Nucleico , Fosfatidiletanolaminas/análise , Polienos/análise , República da Coreia , Análise de Sequência de DNA , Vitamina K 2/análogos & derivados , Vitamina K 2/análise , Microbiologia da Água
6.
Int J Syst Evol Microbiol ; 63(Pt 5): 1639-1645, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-22904215

RESUMO

A Gram-staining-negative, rod-shaped, gliding and pale-pink-pigmented bacterium, designated strain ZLM-10(T), was isolated from a soil sample collected from an arid area in Xinjiang province, China, and characterized in a taxonomic study using a polyphasic approach. The novel strain grew optimally at 30-37 °C and in the presence of 2 % (w/v) sea salts. The only respiratory quinone detected was MK-7 and the major cellular fatty acids were summed feature 3 (iso-C15 : 0 2-OH and/or C16 : 1ω7c), iso-C15 : 0 and iso-C17 : 0 3-OH. The polar lipids consisted of diphosphatidylglycerol, phosphatidylethanolamine, an unidentified aminolipid and two unidentified aminophospholipids. The DNA G+C content was 45.4 mol%. Flexirubin-type pigments were not produced. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain ZLM-10(T) was a member of the phylum Bacteroidetes and appeared most closely related to Cesiribacter roseus 311(T) (90.2 % sequence similarity), Marivirga sericea LMG 13021(T) (89.2 %), Cesiribacter andamanensis AMV16(T) (89.1 %) and Marivirga tractuosa DSM 4126(T) (89.1 %). On the basis of phenotypic and genotypic data and phylogenetic inference, strain ZLM-10(T) should be classified as a novel species of a new genus in the family Flammeovirgaceae, for which the name Nafulsella turpanensis gen. nov., sp. nov. is proposed. The type strain of the type species is ZLM-10(T) ( = CCTCC AB 208222(T) = KCTC 23983(T)).


Assuntos
Bacteroidetes/classificação , Filogenia , Microbiologia do Solo , Técnicas de Tipagem Bacteriana , Bacteroidetes/genética , Bacteroidetes/isolamento & purificação , Composição de Bases , China , DNA Bacteriano/genética , Ácidos Graxos/análise , Dados de Sequência Molecular , Polienos/análise , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Vitamina K 2/análogos & derivados , Vitamina K 2/análise
7.
Int J Syst Evol Microbiol ; 63(Pt 5): 1633-1638, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-22904226

RESUMO

A Gram-stain-negative, rod-shaped, non-motile and yellow-pigmented bacterial strain, designated strain JJ013(T), was isolated from an artificial lake in Jeollabuk-do, South Korea, and characterized using a polyphasic approach. The 16S rRNA gene sequence of strain JJ013(T) indicated that the isolate belonged to the family Flavobacteriaceae and exhibited similarity levels of 96.6 % to the type strains of Flavobacterium cheonanense and Flavobacterium koreense and 96.5 % to the type strain of Flavobacterium chungnamense. Growth was observed at 20-30 °C and pH 5.0-7.0. The major cellular fatty acids of the novel strain were iso-C15 : 0 (27.5 %), iso-C15 : 1 G (17.8 %), iso-C17 : 0 3-OH (9.4 %) and iso-C15 : 0 3-OH (9.2 %). Flexirubin-type pigments were present. The DNA G+C content of strain JJ013(T) was 33.9 mol%, the major respiratory quinone was menaquinone-6 (MK-6) and the major polyamine was sym-homospermidine. The polar lipid profile of the strain JJ013(T) consisted of a phosphatidylethanolamine (PE), two unknown aminolipids (AL1-2), three unidentified lipid (L1-3) and an unknown glycolipid (GL). On the basis of the morphological and physiological properties and biochemical evidence presented, it is concluded that strain JJ013(T) represents a novel species of the genus Flavobacterium, for which the name Flavobacterium aciduliphilum sp. nov. is proposed; the type strain is JJ013(T) ( = KACC 16594(T) = JCM 18211(T)). Since C15 : 0, which is known as a predominant fatty acid of the genus Flavobacterium was not detected in the novel strain and other reference strains, we propose an emended description of the genus Flavobacterium.


Assuntos
Flavobacterium/classificação , Água Doce/microbiologia , Filogenia , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , Ácidos Graxos/análise , Flavobacterium/genética , Flavobacterium/isolamento & purificação , Glicolipídeos/análise , Dados de Sequência Molecular , Polienos/análise , RNA Ribossômico 16S/genética , República da Coreia , Análise de Sequência de DNA , Espermidina/análogos & derivados , Espermidina/análise , Vitamina K 2/análogos & derivados , Vitamina K 2/análise
8.
Artigo em Inglês | MEDLINE | ID: mdl-22243490

RESUMO

POSH are polyolefin oligomeric saturated hydrocarbons, such as oligomers from polyethylene or polypropylene. POSH that have migrated into foods are easily mistaken for mineral oil-saturated hydrocarbons (MOSH). In fact, both POSH and MOSH largely consist of highly isomerised branched and possibly cyclic hydrocarbons, both forming humps of unresolved components in gas chromatography. Chromatograms are reported to show typical elution patterns of POSH and help analysts distinguishing POSH from MOSH as far as possible. Since the structures of the POSH are not fundamentally different from those of the MOSH, it would be prudent to apply the evaluation of the MOSH. However, the migration is frequently beyond that for which safety has been demonstrated. This is shown for a few examples, particularly for powdered formula for babies.


Assuntos
Contaminação de Alimentos , Embalagem de Alimentos , Polienos/análise , Polietilenos/análise , Polipropilenos/análise , Cacau/química , Manipulação de Alimentos , Alimentos em Conserva/análise , Humanos , Lactente , Alimentos Infantis/análise , Fórmulas Infantis/química , Estrutura Molecular , Oryza/química , Tubérculos/química , Polienos/química , Polietilenos/química , Polipropilenos/química , Sementes/química , Solanum tuberosum/química , Propriedades de Superfície , Água/análise , Zea mays/química
9.
Waste Manag ; 31(11): 2217-27, 2011 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-21745732

RESUMO

In this paper new analytical inspection strategies, based on hyperspectral imaging (HSI) in the VIS-NIR and NIR wavelength ranges (400-1000 and 1000-1700 nm, respectively), have been investigated and set up in order to define quality control logics that could be applied at industrial plant level for polyolefins recycling. The research was developed inside the European FP7 Project W2Plastics "Magnetic Sorting and Ultrasound Sensor Technologies for Production of High Purity Secondary Polyolefins from Waste". The main aim of the project is the separation of pure polyethylene and polypropylene adopting an innovative process, the magnetic density separation (MDS). Spectra of plastic particles and contaminants resulting from post-consumer complex wastes and of virgin polyolefins have been acquired by HSI and by Raman spectroscopy. The classification results obtained applying principal component analysis (PCA) on HSI data have been compared with those obtained by Raman spectroscopy, in order to validate the proposed innovative methodology. Results showed that HSI sensing techniques allow to identify both polyolefins and contaminants. Results also demonstrated that HSI has a great potentiality as a tool for quality control of feed (identification of contaminants in the plastic waste) and of the two different pure polypropylene and polyethylene flow streams resulting from the MDS-based recycling process.


Assuntos
Produtos Domésticos/análise , Campos Magnéticos , Polienos/análise , Reciclagem/métodos , Análise Espectral/métodos , Resíduos/análise , Polienos/classificação , Polietileno/análise , Polietileno/classificação , Polipropilenos/análise , Polipropilenos/classificação , Análise de Componente Principal , Controle de Qualidade , Reciclagem/economia , Análise Espectral/classificação , Análise Espectral/instrumentação , Análise Espectral Raman/instrumentação , Resíduos/classificação
10.
Int J Syst Evol Microbiol ; 61(Pt 1): 30-34, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-20139284

RESUMO

A novel bacterial strain, designated M2T2B15(T), was isolated from fermented bovine products and was characterized by using a polyphasic approach. Colonies were reddish pink and circular with entire margins. Cells were strictly aerobic, Gram-reaction-negative, oxidase- and catalase-positive rods that lacked flagella and were motile by gliding. Flexirubin-type pigments were absent. 16S rRNA gene sequence analysis indicated that strain M2T2B15(T) was related most closely to Larkinella insperata LMG 22510(T) (94.4 % similarity) but shared <87 % similarity with other members of the phylum Bacteroidetes. The major cellular fatty acids were C(16 : 1)ω5c, iso-C(15 : 0) and iso-C(17 : 0) 3-OH. The polar lipids were phosphatidylethanolamine, phosphatidylserine, two unidentified aminophospholipids and two unidentified polar lipids. Menaquinone 7 (MK-7) was the major respiratory quinone. The G+C content of the DNA of strain M2T2B15(T) was 52 mol%. The phenotypic, genotypic and phylogenetic data presented clearly indicate that strain M2T2B15(T) represents a novel species of the genus Larkinella, for which the name Larkinella bovis sp. nov. is proposed. The type strain is M2T2B15(T) (=KACC 14040(T) =NBRC 106324(T)). Emended descriptions of the genus Larkinella and of Larkinella insperata Vancanneyt et al. 2006 are also proposed.


Assuntos
Cytophagaceae/classificação , Cytophagaceae/isolamento & purificação , Microbiologia de Alimentos , Animais , Composição de Bases , Catalase/metabolismo , Bovinos , Análise por Conglomerados , Cytophagaceae/genética , Cytophagaceae/fisiologia , DNA Bacteriano/química , DNA Bacteriano/genética , DNA Ribossômico/química , DNA Ribossômico/genética , Ácidos Graxos/análise , Locomoção , Dados de Sequência Molecular , Oxirredutases/metabolismo , Fosfolipídeos/análise , Filogenia , Polienos/análise , Quinonas/análise , RNA Ribossômico 16S/genética , Análise de Sequência de DNA
11.
Anal Chim Acta ; 646(1-2): 85-9, 2009 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-19523559

RESUMO

In this study we explored the spectroscopic properties of Borage oil, particularly the use of fluorescence techniques to investigate the presence of conjugated fatty acids (CFAs). This research has important health and dietary applications. The absorption and fluorescence spectra of different CFAs and Borage oil in ethanol were measured. Time-domain fluorescence was employed to establish the life times of the samples. We found that Borage oil contains 1.2x10(-3) mol L(-1) of alpha-eleostearic acid or its isomer (i.e., a conjugated triene), 1.6x10(-4) mol L(-1) of cis-parinaric acid (i.e., a conjugated tetraene) and 1.1x10(-5) mol L(-1) of c-COPA (i.e., a conjugated pentaene). Because of the three-exponential fluorescence intensity decay for Borage oil, other fatty acids with a four conjugated double bond system could not be excluded.


Assuntos
Óleos de Plantas/química , Polienos/análise , Ácido gama-Linolênico/química , Ácidos Graxos/química , Corantes Fluorescentes/química , Ácidos Linolênicos/análise , Ácidos Linolênicos/química , Polienos/química , Espectrometria de Fluorescência/métodos , Fatores de Tempo
12.
Waste Manag ; 29(5): 1712-7, 2009 May.
Artigo em Inglês | MEDLINE | ID: mdl-19128952

RESUMO

Polyolefin fractions are often end fractions resulting from the recycling of end-of-life consumer products. Polypropylene (PP) and polyethylene (PE) are present in such fractions as a mixture. For instance, the ratio of PP and PE in car scrap is 70:30 on average. However, the grade of the PP and PE should typically be better than 97% to be reused again as a high quality product. Density separation of the different polyolefins can be a solution. A promising separation technique is the inverse magnetic density separator (IMDS). This paper discusses the potential of shredder residue, one of the possible polyolefin's waste stream sources for the IMDS, in detail. Experiments with the separation of polyolefins with an IMDS prototype show both high grade and high recovery. The paper concludes with the economic opportunities of the IMDS in the recycling of polyolefins.


Assuntos
Conservação dos Recursos Naturais/métodos , Produtos Domésticos/análise , Magnetismo , Polienos/análise , Eliminação de Resíduos/métodos , Resíduos/análise , Conservação dos Recursos Naturais/economia
13.
J Agric Food Chem ; 57(4): 1433-9, 2009 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-19173603

RESUMO

Galbanum oil is composed of monoterpenes in large amounts and pyrazines in small amounts. Although the monoterpenes are the main components of galbanum oil, they hardly contribute to the distinct galbanum aroma. The scanty amounts of pyrazines, in contrast, contribute significantly to the aroma. Considering the complexity and potency of the odor, the essential oil was assumed to contain so far not identified compounds with high odor contribution. By the gas chromatography-mass spectrometry-olfactometry (GC-MS-O) analysis of galbanum oil, fruity-green-balsamic notes were detected at two different retention times. The mass spectra (MS) of the newly discovered notes were elucidated by conducting multidimensional (MD) GC-MS-O. By analyzing the MS data, six chemical structures were proposed: (6E/Z,8E)-undeca-6,8,10-trien-2-one, (6E/Z,8E)-undeca-6,8,10-trien-3-one, and (6E/Z,8E)-undeca-6,8,10-trien-4-one. The compounds were then synthesized in an attempt to match the MS, retention indices (RI), and odor qualities. The MD-GC-MS-O analyses of the candidate compounds led to the identification of the novel key aroma compounds (6Z,8E)-undeca-6,8,10-trien-3-one and (6Z,8E)-undeca-6,8,10-trien-4-one in galbanum oil.


Assuntos
Ferula/química , Odorantes/análise , Óleos Voláteis/química , Óleos de Plantas/química , Cromatografia Gasosa-Espectrometria de Massas , Humanos , Monoterpenos/análise , Polienos/análise , Pirazinas/análise , Olfato
14.
Int J Syst Evol Microbiol ; 56(Pt 5): 1059-1065, 2006 May.
Artigo em Inglês | MEDLINE | ID: mdl-16627655

RESUMO

Bacterial strains UST030701-097T and UST030701-084T were isolated from a marine sponge in the Bahamas. Both strains were pink-pigmented, Gram-negative, strictly aerobic and chemo-organotrophic. Cells of strain UST030701-097T were short, curved rods with fast-gliding motility, whereas those of strain UST030701-084T were straight rods with a less rapid gliding motion. The two strains had MK-7 as the major respiratory quinone and did not produce flexirubin-type pigments. The DNA G+C contents of strains UST030701-097T and UST030701-084T were 42.5 and 43.7 mol%, respectively. Phylogenetic analysis based on 16S rRNA gene sequences indicated that the two strains belonged to the family 'Flexibacteraceae' of the phylum Bacteroidetes. 16S rRNA gene sequence similarity between strains UST030701-097T and UST030701-084T was 95.0 %; their closest relative was [Marinicola] seohaensis, with 93.3 % and 96.0 % sequence similarity, respectively. Phylogenetic tree topology indicated that the two strains belonged to the same lineage, but were on separate branches. Whilst strain UST030701-084T and [Marinicola] seohaensis were found on one branch, strain UST030701-097T was in another branch that had no species with validly published names. Based on the polyphasic taxonomic data obtained in the present study, we propose that strain UST030701-097T represents a novel genus and that strain UST030701-084T represents a novel species in the phylum Bacteroidetes. The genus Fabibacter gen. nov. is proposed, with strain UST030701-097T (=NRRL B-41220T=JCM 13334T) as the type strain of the type species, Fabibacter halotolerans sp. nov. Strain UST030701-084T (=NRRL B-41219T=JCM 13337T) is proposed as the type strain of Roseivirga spongicola sp. nov. In an earlier study, it was suggested that the genus Marinicola is a later heterotypic synonym of the genus Roseivirga. However, a formal proposal to reclassify [Marinicola] seohaensis, the only member of the genus Marinicola, has not yet been made. The results of phylogenetic analyses in this study support the reclassification of [Marinicola] seohaensis as Roseivirga seohaensis comb. nov.


Assuntos
Cytophagaceae/classificação , Cytophagaceae/isolamento & purificação , Poríferos/microbiologia , Aerobiose , Animais , Técnicas de Tipagem Bacteriana , Bahamas , Composição de Bases , Cytophagaceae/citologia , Cytophagaceae/fisiologia , DNA Bacteriano/química , DNA Bacteriano/genética , DNA Ribossômico/química , DNA Ribossômico/genética , Genes de RNAr , Violeta Genciana , Biologia Marinha , Dados de Sequência Molecular , Movimento , Fenazinas , Filogenia , Pigmentos Biológicos/biossíntese , Polienos/análise , Quinonas/análise , Quinonas/isolamento & purificação , RNA Bacteriano/genética , RNA Ribossômico 16S/genética , Análise de Sequência de DNA
15.
Food Addit Contam ; 22(10): 1012-22, 2005 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-16227185

RESUMO

A procedure used by the Norwegian Food Safety Authority for surveillance of contaminants from plastic food contact materials (polyolefin drinking bottles, water boilers, polyamide cooking utensils and plastic multi-layer materials) is described. It is based on gas chromatographic-mass spectrometric (GC/MS) analysis of food simulants exposed to plastic materials. Most migrants were substances not-intentionally added to the plastic (degradation products, impurities) or originated from non-plastic components, such as printing inks, adhesives, not-listed additives, solvents and coatings. Hence, the majority of the identified migrants were regulated by the general statements in the EU Framework Regulation, which neither specify limits nor requirements regarding risk assessment, rather than by specific migration controls. Risk assessment has been carried out for selected non-authorized substances. The analysis and the management of these substances and materials with respect to safety represents a challenge to the food authorities.


Assuntos
Contaminação de Alimentos , Embalagem de Alimentos , Plásticos , Compostos de Anilina/análise , Carcinógenos Ambientais/análise , Utensílios de Alimentação e Culinária , Cicloexanonas/análise , Exposição Ambiental/efeitos adversos , União Europeia , Cromatografia Gasosa-Espectrometria de Massas/métodos , Utensílios Domésticos , Humanos , Nylons/análise , Fenóis/análise , Polienos/análise , Medição de Risco/métodos , Sulfonamidas/análise , Tolueno/análogos & derivados , Tolueno/análise , Água/química
16.
Scand J Gastroenterol ; 38(5): 549-55, 2003 May.
Artigo em Inglês | MEDLINE | ID: mdl-12795469

RESUMO

BACKGROUND: The free water phase of feces (fecal water) may mediate the effects of diet on colon carcinogenesis. We examined the effects of fecal water from adenoma patients and controls on three parameters in colonocytes believed to be relevant to tumorigenesis, i.e. genotoxicity in intact cells and on isolated DNA, proliferative activity and activator protein-1 (AP-1) activity. METHODS: Genotoxicity in intact colonic cells was assayed using the single-cell gel electrophoresis assay ('comet' assay) and on isolated DNA using double-stranded DNA from the X-174 RF plasmid. Cell proliferation was assessed using the commercially available 'alamar blue' proliferation kit and AP-1 activity using cells transiently transfected with an AP-1-luciferase reporter construct. RESULTS: The data showed that lipid extracts of fecal water samples from the adenoma patients had a significantly higher capacity to induce cell proliferation than those from controls, and that this effect could be explained to a large extent by the concentrations of deoxycholic and chenodeoxycholic acids in the fecal water using regression models. No difference between patients and controls was observed for induction of AP-1 activity or induction of DNA strand breaks in intact cells. However, induction of DNA strand breaks in isolated DNA was significantly higher for the fecal waters from patients than for those from controls, which could be explained in part in a regression model by concentrations of lithocholic acid in fecal water and fecapentaene-12 in feces. CONCLUSIONS: Our results support the hypothesis that the biochemistry of fecal waters from adenoma patients and controls differs.


Assuntos
Adenoma/metabolismo , Água Corporal/química , Divisão Celular/efeitos dos fármacos , Neoplasias Colorretais/metabolismo , Fezes/química , Fator de Transcrição AP-1/efeitos dos fármacos , Adulto , Ácidos Cólicos/análise , Ácidos Cólicos/metabolismo , Dano ao DNA , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Polienos/análise , Polienos/metabolismo
18.
Nutr Cancer ; 18(1): 53-8, 1992.
Artigo em Inglês | MEDLINE | ID: mdl-1408946

RESUMO

Fusarin C (FC) is a naturally occurring mutagen found on Fusarium moniliforme-contaminated corn. In Linxian, China, an area of exceptionally high incidence of esophageal cancer, the milled corn is made into small cakes called wotou, which are steamed. It has been suggested that FC may play a role in the etiology of esophageal cancer, but this has been questioned, in part, because of the thermal instability of FC. We therefore measured the effects of temperature on FC stability, mimicking the cooking process. FC was extracted from the wotou and quantitated by both reverse-phase high-performance liquid chromatography and the Ames assay. After wotou were steamed for 30 minutes, 11% and 3% of the initial FC remained, as detected by the two assays, respectively. The milled corn, when moistened with water, had a pH of 6.1, which was lowered to 5.3 when it was inoculated with F. moniliforme and cultured for three weeks. Pickled vegetables are sometimes added to the wotou, which further reduces the pH. To determine the effects of pH on FC, it was heated in solution, with the pH varied between 4 and 8. Its stability was very pH dependent, decomposing more rapidly as the pH increased. Because ingested FC would also be subjected to the low pH of the stomach, it was treated for 30 minutes at 37 degrees C and pH values ranging from 1.0 to 7.0. FC was stable (less than 15% decomposition) under these conditions. If FC is a significant health threat, it could most easily be destroyed by cooking at slightly basic pH values.


Assuntos
Culinária , Mutagênicos/química , Polienos/química , China , Cromatografia Líquida de Alta Pressão , Estabilidade de Medicamentos , Neoplasias Esofágicas/epidemiologia , Humanos , Concentração de Íons de Hidrogênio , Mutagênicos/análise , Polienos/análise , Zea mays/química
19.
Mycopathologia ; 115(1): 37-43, 1991 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-1922268

RESUMO

Ten different isolates of the common corn fungus, Fusarium moniliforme, were cultured on corn, and the production by the isolates of two important mycotoxins, fusarin C and fumonisin B1, was compared. Additionally, both aqueous and organic extracts of the cultures were tested for cytotoxicity to rat primary hepatocytes by measuring the effects of three dose levels on the ability of the cells to take up valine and to cause the release of the cytoplasmic enzyme, lactate dehydrogenase. The fungal isolates differed drastically in their ability to produce the two mycotoxins and in their cytotoxicity. However the toxic effects could not be accounted for by the content of the two toxins measured. Therefore it appears that there are other toxins, both organic and aqueous soluble compounds, that are toxic to liver cells.


Assuntos
Carcinógenos Ambientais/análise , Fumonisinas , Fusarium/metabolismo , Mutagênicos/análise , Micotoxinas/biossíntese , Polienos/análise , Animais , Bioensaio , Células Cultivadas , Meios de Cultura , L-Lactato Desidrogenase/metabolismo , Fígado/citologia , Fígado/enzimologia , Masculino , Micotoxinas/análise , Ratos , Ratos Endogâmicos , Análise de Regressão , Valina/metabolismo , Zea mays
20.
Am J Clin Nutr ; 51(4): 698-704, 1990 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-2108580

RESUMO

People in developed nations such as the United States and Canada have an increased risk of colon cancer. Fecal mutagens have been detected in the feces of individuals at high risk for colon cancer. We describe a rapid, sensitive, reliable, reproducible high-pressure liquid chromatography (HPLC) method for detecting fecapentaenes, the most active and chief mutagen found in human stool. We found fecapentaene in all the stool samples of adults on typical high-fat, low-fiber Western diets. These fecapentaene concentrations remained largely constant when subjects consumed constant diets. Fecapentaene concentrations were reduced for total-parenteral-nutrition (TPN) patients with severe intestinal malabsorption. This finding with TPN patients may reflect changes in important variables of gut microflora in fecapentaene production. Studies with newborns and children showed that fecapentaenes appeared very early in life but are not present in stool at birth.


Assuntos
Envelhecimento/metabolismo , Fezes/análise , Nutrição Parenteral Total , Polienos/análise , Adulto , Fatores Etários , Criança , Pré-Escolar , Cromatografia Líquida de Alta Pressão , Dieta , Gorduras na Dieta/metabolismo , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Reprodutibilidade dos Testes , Manejo de Espécimes
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