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1.
Compr Rev Food Sci Food Saf ; 23(4): e13377, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38865251

RESUMEN

Climate change and changing consumer demand are the main factors driving the protein transition. This shift toward more sustainable protein sources as alternatives to animal proteins is also reflected in the rapid upscaling of meat and dairy food analogues. Such changes could challenge food safety, as new food sources could result in new and unexpected food safety risks for consumers. This review analyzed the current knowledge on chemical and microbiological contamination of emerging alternative protein sources of plant origin, including soil-based (faba bean, mung bean, lentils, black gram, cowpea, quinoa, hemp, and leaf proteins) and aquatic-based (microalgae and duckweeds) proteins. Moreover, findings on commercial analogues from known alternative protein sources were included. Overall, the main focus of the investigations is on the European context. The review aimed to enable foresight approaches to food safety concerning the protein transition. The results indicated the occurrence of multiple chemical and microbiological hazards either in the raw materials that are the protein sources and eventually in the analogues. Moreover, current European legislation on maximum limits does not address most of the "contaminant-food" pairs identified, and no legislative framework has been developed for analogues. Results of this study provide stakeholders with a more comprehensive understanding of the chemical and microbiological safety of alternative protein sources and derived analogues to enable a holistic and safe approach to the protein transition.


Asunto(s)
Contaminación de Alimentos , Inocuidad de los Alimentos , Contaminación de Alimentos/prevención & control , Contaminación de Alimentos/análisis , Microbiología de Alimentos , Proteínas de Plantas/química , Animales
2.
J Antimicrob Chemother ; 71(3): 739-50, 2016 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-26679249

RESUMEN

OBJECTIVES: This study aims to evaluate the reliability and clinical utility of NS3 sequencing in hepatitis C virus (HCV) 1-infected patients who were candidates to start a PI-containing regimen. METHODS: NS3 protease sequencing was performed by in-house-developed HCV-1 subtype-specific protocols. Phylogenetic analysis was used to test sequencing reliability and concordance with previous genotype/subtype assignment by commercial genotyping assays. RESULTS: Five hundred and sixty-seven HCV plasma samples with quantifiable HCV-RNA from 326 HCV-infected patients were collected between 2011 and 2014. Overall, the success rate of NS3 sequencing was 88.9%. The success rate between the two subtype protocols (HCV-1a/HCV-1b) was similarly high for samples with HCV-RNA >3 log IU/mL (>92% success rate), while it was slightly lower for HCV-1a samples with HCV-RNA ≤3 log IU/mL compared with HCV-1b samples. Phylogenetic analysis confirmed the genotype/subtype given by commercial genotyping assays in 92.9% (303/326) of cases analysed. In the remaining 23 cases (7.1%), 1 was HCV-1g (previously defined as subtype 1a), 1 was HCV-4d (previously defined as genotype 1b) and 1 was HCV-1b (previously defined as genotype 2a/2c). In the other cases, NS3 sequencing precisely resolved the either previous undetermined/discordant subtype 1 or double genotype/subtype assignment by commercial genotyping assays. Resistance-associated variants (RAVs) to PI were detected in 31.0% of samples. This prevalence changed according to PI experience (17.1% in PI-naive patients versus 79.2% in boceprevir/telaprevir/simeprevir-failing patients). Among 96 patients with available virological outcome following boceprevir/telaprevir treatment, a trend of association between baseline NS3 RAVs and virological failure was observed (particularly for HCV-1a-infected patients: 3/21 failing patients versus 0/22 achieving sustained virological response; P = 0.11). CONCLUSIONS: HCV-NS3 sequencing provides reliable results and at the same time gives two clinically relevant pieces of information: a correct subtype/genotype assignment and the detection of variants that may interfere with the efficacy of PI.


Asunto(s)
Farmacorresistencia Viral , Técnicas de Genotipaje/métodos , Hepacivirus/clasificación , Hepacivirus/efectos de los fármacos , Hepatitis C/virología , Mutación , Proteínas no Estructurales Virales/genética , Genotipo , Hepacivirus/genética , Hepacivirus/aislamiento & purificación , Humanos , ARN Viral/genética , Estudios Retrospectivos , Análisis de Secuencia de ADN
3.
Chemphyschem ; 17(2): 317-24, 2016 Jan 18.
Artículo en Inglés | MEDLINE | ID: mdl-26541507

RESUMEN

Noncovalent interactions of cis- and trans-2-butene, as the smallest model systems of molecules with cis and trans double bonds, were studied to find potential differences in interactions of these molecules. The study was performed using quantum chemical methods including very accurate CCSD(T)/CBS method. We studied parallel and displaced parallel interactions in 2-butene dimers, in butane dimers, and between 2-butene and saturated butane. The results show the trend that interactions of 2-butene with butane are the strongest, followed by interactions in butane dimers, whereas the interaction in 2-butene dimers are the weakest. The strongest calculated interaction energy is between trans-2-butene and butane, with a CCSD(T)/CBS energy of -2.80 kcal mol(-1) . Interactions in cis-2-butene dimers are stronger than interactions in trans-2-butene dimers. Interestingly, some of the interactions involving 2-butene are as strong as interactions in a benzene dimer. These insights into interactions of cis- and trans-2-butene can improve understanding of the properties and processes that involve molecules with cis and trans double bonds, such as fatty acids and polymers.

4.
Front Public Health ; 12: 1234584, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38450141

RESUMEN

Introduction: Self-immolation is an uncommon way of attempting and committing a suicide, with a fatality rate of 80%. The risk factors in self-immolation victims vary depending on demographic characteristics, socio-economic and cultural factors as well as religious beliefs. Whether the COVID-19 pandemic was a potentially important stressor for self-immolation is still unknown, with insufficient studies examining this issue. Therefore, in this study, we aimed to examine the trend of self-immolation in a 13-year timeline, and the potential association of COVID-19 pandemic with the increase in the incidence and severity of self-immolation injuries in Serbia in 2021. Materials and methods: The study included hospitalized patients due to intentional burns caused by self-immolation in the period from January 1, 2008 to December 31, 2021. Joinpoint regression analysis was used for the analysis of continuous linear trends of self-immolation cases with change points. Results: While a rising trend was observed in the 2008-2013 time segment, followed by a decline in the upcoming 2013-2016 time segment, a significant increase reached its maximum during COVID-19 pandemic (2021), with annual percent change of 37.1% (p = 0.001). A significant increase in the median number of cases per year was observed during 2021 compared to the previous periods (7.5 vs. 2). Frequency of patients with a psychiatric diagnosis vs. those without a psychiatric diagnosis was significantly higher during than before the COVID-19 period (66.7 vs. 36.1%, p = 0.046). Conclusion: In our study, a significant increase in the frequency of suicide attempts by self-immolation during COVID-19 pandemic was noticed. There was also an increased frequency of pre-existing psychiatric illness among patients during the pandemic period. With limited high-quality data available, the study adds to a rising body of evidence for assessment of outcomes of the pandemic on mental health and recognition of stressors for self-immolation.


Asunto(s)
COVID-19 , Trastornos Mentales , Humanos , COVID-19/epidemiología , Pandemias , Exactitud de los Datos , Salud Mental
5.
Physiol Genomics ; 45(1): 47-57, 2013 Jan 07.
Artículo en Inglés | MEDLINE | ID: mdl-23170035

RESUMEN

11ß-Hydroxysteroid dehydrogenase type 1 (11ß-HSD1) is implicated in the etiology of metabolic syndrome. We previously showed that pharmacological inhibition of 11ß-HSD1 ameliorated multiple facets of metabolic syndrome and attenuated atherosclerosis in ApoE-/- mice. However, the molecular mechanism underlying the atheroprotective effect was not clear. In this study, we tested whether and how 11ß-HSD1 inhibition affects vascular inflammation, a major culprit for atherosclerosis and its associated complications. ApoE-/- mice were treated with an 11ß-HSD1 inhibitor for various periods of time. Plasma lipids and aortic cholesterol accumulation were quantified. Several microarray studies were carried out to examine the effect of 11ß-HSD1 inhibition on gene expression in atherosclerotic tissues. Our data suggest 11ß-HSD1 inhibition can directly modulate atherosclerotic plaques and attenuate atherosclerosis independently of lipid lowering effects. We identified immune response genes as the category of mRNA most significantly suppressed by 11ß-HSD1 inhibition. This anti-inflammatory effect was further confirmed in plaque macrophages and smooth muscle cells procured by laser capture microdissection. These findings in the vascular wall were corroborated by reduction in circulating MCP1 levels after 11ß-HSD1 inhibition. Taken together, our data suggest 11ß-HSD1 inhibition regulates proinflammatory gene expression in atherosclerotic tissues of ApoE-/- mice, and this effect may contribute to the attenuation of atherosclerosis in these animals.


Asunto(s)
11-beta-Hidroxiesteroide Deshidrogenasa de Tipo 1/antagonistas & inhibidores , Aterosclerosis/tratamiento farmacológico , Inhibidores Enzimáticos/farmacología , Regulación de la Expresión Génica/efectos de los fármacos , Vasculitis/tratamiento farmacológico , 11-beta-Hidroxiesteroide Deshidrogenasa de Tipo 1/metabolismo , Animales , Apolipoproteínas E/genética , Aterosclerosis/etiología , Colesterol/metabolismo , Perfilación de la Expresión Génica , Genes MHC Clase II/genética , Glucocorticoides/metabolismo , Captura por Microdisección con Láser , Lípidos/sangre , Ratones , Ratones Noqueados , Análisis por Micromatrices , Vasculitis/complicaciones
6.
ACS Med Chem Lett ; 12(3): 337-342, 2021 Mar 11.
Artículo en Inglés | MEDLINE | ID: mdl-33738059

RESUMEN

An integrated workflow has been established that enables the synthesis, purification, and subsequent biological testing of compound libraries on a microgram scale. This approach utilizes mass directed preparative HPLC in conjunction with charged aerosol detection (CAD) to generate solutions of investigational compounds at high purity and standardized concentrations, facilitating high fidelity biological testing. This new workflow successfully delivered libraries of histone deacetylase (HDAC) inhibitors that afforded biological data consistent with that obtained from standard scale parallel medicinal chemistry techniques. The advantages of this new approach to library synthesis include greatly reduced material requirements and amenability to high-throughput experimentation.

7.
Plants (Basel) ; 10(9)2021 Sep 09.
Artículo en Inglés | MEDLINE | ID: mdl-34579403

RESUMEN

Centaurium erythraea (centaury) is a medicinal plant with exceptional developmental plasticity in vitro and vigorous, often spontaneous, regeneration via shoot organogenesis and somatic embryogenesis, during which arabinogalactan proteins (AGPs) play an important role. AGPs are highly glycosylated proteins belonging to the super family of O-glycosylated plant cell surface hydroxyproline-rich glycoproteins (HRGPs). HRGPs/AGPs are intrinsically disordered and not well conserved, making their homology-based mining ineffective. We have applied a recently developed pipeline for HRGP/AGP mining, ragp, which is based on machine learning prediction of proline hydroxylation, to identify HRGP sequences in centaury transcriptome and to classify them into motif and amino acid bias (MAAB) classes. AGP sequences with low AG glycomotif representation were also identified. Six members of each of the three AGP subclasses, fasciclin-like AGPs, receptor kinase-like AGPs and AG peptides, were selected for phylogenetic and expression analyses. The expression of these 18 genes was recorded over 48 h following leaf mechanical wounding, as well as in 16 tissue samples representing plants from nature, plants cultivated in vitro, and developmental stages during shoot organogenesis and somatic embryogenesis. None of the selected genes were upregulated during both wounding recovery and regeneration. Possible functions of AGPs with the most interesting expression profiles are discussed.

8.
Plants (Basel) ; 10(1)2021 Jan 14.
Artículo en Inglés | MEDLINE | ID: mdl-33466920

RESUMEN

Aquaporins comprise a large group of transmembrane proteins responsible for water transport, which is crucial for plant survival under stress conditions. Despite the vital role of aquaporins, nothing is known about this protein family in Impatiens walleriana, a commercially important horticultural plant, which is sensitive to drought stress. In the present study, attention is given to the molecular characterization of aquaporins in I. walleriana and their expression during drought stress and recovery. We identified four I. walleriana aquaporins: IwPIP1;4, IwPIP2;2, IwPIP2;7 and IwTIP4;1. All of them had conserved NPA motifs (Asparagine-Proline-Alanine), transmembrane helices (TMh), pore characteristics, stereochemical properties and tetrameric structure of holoprotein. Drought stress and recovery treatment affected the aquaporins expression in I. walleriana leaves, which was up- or downregulated depending on stress intensity. Expression of IwPIP2;7 was the most affected of all analyzed I. walleriana aquaporins. At 15% and 5% soil moisture and recovery from 15% and 5% soil moisture, IwPIP2;7 expression significantly decreased and increased, respectively. Aquaporins IwPIP1;4 and IwTIP4;1 had lower expression in comparison to IwPIP2;7, with moderate expression changes in response to drought and recovery, while IwPIP2;2 expression was of significance only in recovered plants. Insight into the molecular structure of I. walleriana aquaporins expanded knowledge about plant aquaporins, while its expression during drought and recovery contributed to I. walleriana drought tolerance mechanisms and re-acclimation.

9.
ACS Med Chem Lett ; 11(12): 2476-2483, 2020 Dec 10.
Artículo en Inglés | MEDLINE | ID: mdl-33335670

RESUMEN

The selectivity of histone deacetylase inhibitors (HDACis) is greatly impacted by the zinc binding groups. In an effort to search for novel zinc binding groups, we applied a parallel medicinal chemistry (PMC) strategy to quickly synthesize substituted benzamide libraries. We discovered a series containing 2-substituted benzamides as the zinc binding group which afforded highly selective and potent HDAC3 inhibitors, exemplified by compound 16 with a 2-methylthiobenzamide. Compound 16 inhibited HDAC3 with an IC50 of 30 nM and with unprecedented selectivity of >300-fold over all other HDAC isoforms. Interestingly, a subtle change of the 2-methylthio to a 2-hydroxy benzamide in 20 retains HDAC3 potency but loses all selectivity over HDAC 1 and 2. This significant difference in selectivity was rationalized by X-ray crystal structures of HDACis 16 and 20 bound to HDAC2, revealing different binding modes to the catalytic zinc ion. This series of HDAC3 selective inhibitors served as tool compounds for investigating the minimal set of HDAC isoforms that must be inhibited for the HIV latency activation in a Jurkat 2C4 cell model and potentially as leads for selective HDAC3 inhibitors for other indications.

10.
Environ Sci Pollut Res Int ; 24(27): 21885-21893, 2017 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-28779342

RESUMEN

Modern, efficient, and cost-effective approach to remediation of heavy metal-contaminated soil is based on the application of microorganisms. In this paper, four isolates from agricultural and urban contaminated soil showed abundant growth in the presence of copper(II) sulfate pentahydrate (CuSO4·5H2O) up to 2 mM. Selected yeasts were identified by molecular methods as Candida tropicalis (three isolates) and Schwanniomyces occidentalis (one isolate). C. tropicalis (4TD1101S) showed the highest percentage of bioaccumulation capabilities (94.37%), determined by the inductively coupled plasma optical emission spectrometry (ICP-OES). The Raman spectra of C. tropicalis (4TD1101S) analyzed in a medium with the addition of 2 mM CuSO4·5H2O showed certain increase in metallothionein production, which represents a specific response of the yeast species to the stress conditions. These results indicate that soil yeasts represent a potential for practical application in the bioremediation of contaminated environments.


Asunto(s)
Candida tropicalis/metabolismo , Cobre/metabolismo , Microbiología del Suelo , Contaminantes del Suelo/metabolismo , Biodegradación Ambiental , Candida tropicalis/efectos de los fármacos , Candida tropicalis/aislamiento & purificación , Cobre/toxicidad , Estrés Oxidativo/efectos de los fármacos , Suelo/química , Contaminantes del Suelo/toxicidad , Espectrometría Raman
12.
Food Chem Toxicol ; 24(1): 23-6, 1986 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-3949266

RESUMEN

Global migration from several plastics (phthalate-plasticized PVC, polyurethane, polyether-polyamide copolymer and silicone rubber) into olive oil, used as a liquid simulant for fatty foods, was compared with global migration into isooctane, which has been proposed as a new fatty-food simulant. The results showed that the isooctane test (involving contact for 2 hr at 40 degrees C) is not suitable as a substitute for the olive oil test (contact for 10 days at 40 degrees C) for some types of commercial plastic materials.


Asunto(s)
Contaminación de Alimentos , Manipulación de Alimentos , Plásticos , Alcanos , Aceites
13.
Farmaco ; 45(6 Suppl): 783-90, 1990 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-2400528

RESUMEN

A simple and rapid method has been developed for fast selective determination of residues of methyl bromide in food products. The method is based on the use of a GC/MS computer-aided system equipped with a headspace. Analysis of methyl bromide was carried out directly on the food products without preliminary extraction of fumigant. An MSD quadrupole mass spectrometer with data processing allowed rapid identification of the separated volatile compound in the samples. The technique of focusing on characteristic single ion monitoring for quantification of methyl bromide, compared with chromatographic peak area measurement, turned out to have a good degree of accuracy and sensitivity. The use of known amount of added methyl bromide allowed better evaluation of traces of this compound. The proposed method was applied to the analysis of methyl bromide residues in alimentary pastes, white flour, rice, hazelnuts, peanuts and dried mushrooms (boletus).


Asunto(s)
Análisis de los Alimentos , Hidrocarburos Bromados/análisis , Cromatografía de Gases y Espectrometría de Masas , Tamaño de la Partícula , Residuos de Plaguicidas/análisis
14.
Artículo en Inglés | MEDLINE | ID: mdl-24341373

RESUMEN

The development of a scheme for the safety evaluation of mechanical recycling processes for polyethylene terephthalate (PET) is described. The starting point is the adoption of a threshold of toxicological concern such that migration from the recycled PET should not give rise to a dietary exposure exceeding 0.0025 µg kg(-1) bw day(-1), the exposure threshold value for chemicals with structural alerts raising concern for potential genotoxicity, below which the risk to human health would be negligible. It is practically impossible to test every batch of incoming recovered PET and every production batch of recycled PET for all the different chemical contaminants that could theoretically arise. Consequently, the principle of the safety evaluation is to measure the cleaning efficiency of a recycling process by using a challenge test with surrogate contaminants. This cleaning efficiency is then applied to reduce a reference contamination level for post-consumer PET, conservatively set at 3 mg kg(-1) PET for a contaminant resulting from possible misuse by consumers. The resulting residual concentration of each contaminant in recycled PET is used in conservative migration models to calculate migration levels, which are then used along with food consumption data to give estimates of potential dietary exposure. The default scenario, when the recycled PET is intended for general use, is that of an infant weighing 5 kg and consuming every day powdered infant formula reconstituted with 0.75 L of water coming from water bottles manufactured with 100% recycled PET. According to this scenario, it can be derived that the highest concentration of a substance in water that would ensure that the dietary exposure of 0.0025 µg kg(-1) bw day(-1) is not exceeded, is 0.017 µg kg(-1) food. The maximum residual content that would comply with this migration limit depends on molecular weight and is in the range 0.09-0.32 mg kg(-1) PET for the typical surrogate contaminants.


Asunto(s)
Contaminación de Alimentos/análisis , Embalaje de Alimentos , Análisis de Peligros y Puntos de Control Críticos/métodos , Tereftalatos Polietilenos/análisis , Tereftalatos Polietilenos/toxicidad , Reciclaje/métodos , Unión Europea , Contaminación de Alimentos/prevención & control , Embalaje de Alimentos/legislación & jurisprudencia , Humanos , Peso Molecular , Nivel sin Efectos Adversos Observados , Tereftalatos Polietilenos/química , Medición de Riesgo
15.
Clin Ter ; 164(1): e17-21, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-23455746

RESUMEN

AIMS: Recent research has shown that there are many effects of climate change on aeroallergens and thus allergic diseases in humans. It is not easy to evaluate the impact of climate change and air pollution on the prevalence of allergic diseases. The present study is devoted to decipher the possible relationships between climatic changes and allergic diseases, and in particular with atopic dermatitis (AD). MATERIALS AND METHODS: To evaluate the aeroallergens effects on AD, we submitted to an allergological study protocol 59 children patients with AD to study the interaction between aeroallergens-atopy patch test (APT) and skin prick test (SPT). The same tests were performed on to the same patients after 24 months to assess the time trend. RESULTS: We found a high prevalence of house dust mites and grasses pollen APT positivity in AD's and in respiratory patients and we also found an increase in positive results in the same patients after 24 months. However, we observed a variation in the control group, in which in earlier tests all patients had negative results but after 24 months we found some positivity. CONCLUSION: We found a correlation between APT and SPT in AD and we observed a concordance between APT results and the atopy score index, underlying the triggering role of these aereoallergens in the atopic patient's skin reactivity.


Asunto(s)
Contaminación del Aire/efectos adversos , Alérgenos/inmunología , Cambio Climático , Dermatitis Atópica/inmunología , Pyroglyphidae/inmunología , Pruebas Cutáneas/métodos , Animales , Estudios de Casos y Controles , Niño , Dermatitis Atópica/diagnóstico , Dermatitis Atópica/epidemiología , Femenino , Estudios de Seguimiento , Humanos , Hipersensibilidad Inmediata/inmunología , Inmunoglobulina E/sangre , Italia/epidemiología , Masculino , Pruebas del Parche/métodos , Poaceae , Polen/efectos adversos , Valor Predictivo de las Pruebas , Prevalencia , Sensibilidad y Especificidad , Índice de Severidad de la Enfermedad
16.
Clin Ter ; 164(3): e207-9, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-23868640

RESUMEN

Alitretinoin is a unique retinoid authorised for the treatment of adults with severe chronic hand eczema (CHE) refractory to potent topical steroids. The most common adverse events (AEs) were typical class effects of oral retinoids including headache, flushing and skin disorders. To our knowledge, there are no cases of sensitization to alitretinoin reported in literature. We present a case of sensitization to alitretinoin.


Asunto(s)
Erupciones por Medicamentos/etiología , Dermatosis de la Mano/etiología , Tretinoina/efectos adversos , Adulto , Alitretinoína , Femenino , Humanos
17.
Clin Ter ; 163(3): e127-8, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-22964704

RESUMEN

Systemic contact dermatitis (SCD) can be caused by nickel in sensitized subjects. Nickel allergy is commonly characterized by localized reactions ensuring cutaneous exposure to this element. Systemic reactions can occur after dietary nickel ingestion. We report a case of a woman with Systemic Contact Dermatitis due to nickel.


Asunto(s)
Dermatitis Alérgica por Contacto/etiología , Dieta , Níquel/efectos adversos , Anciano , Femenino , Humanos
18.
J Lipid Res ; 48(2): 472-82, 2007 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-17090660

RESUMEN

Endothelial lipase (EL) has been shown to be a critical determinant for high density lipoprotein cholesterol levels in vivo; therefore, assays that measure EL activity have become important for the discovery of small molecule inhibitors that specifically target EL. Here, we describe fluorescent Bodipy-labeled substrates that can be used in homogeneous, ultra-high-throughput kinetic assays that measure EL phospholipase or triglyceride lipase activities. Triton X-100 detergent micelles and synthetic HDL particles containing Bodipy-labeled phospholipid or Bodipy-labeled triglyceride substrates were shown to be catalytic substrates for EL, LPL, and HL. More importantly, only synthetic HDL particles containing Bodipy-labeled triglyceride were ideal substrates for EL, LPL, and HL in the presence of high concentrations of human or mouse serum. These data suggest that substrate presentation is a critical factor when determining EL activity in the presence of serum.


Asunto(s)
Colorantes Fluorescentes/análisis , Colorantes Fluorescentes/metabolismo , Lipasa/sangre , Lipasa/metabolismo , Animales , Fluorescencia , Humanos , Ratones , Estructura Molecular
19.
Food Addit Contam ; 22(1): 73-90, 2005 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-15895614

RESUMEN

Materials and articles intended to come into contact with food must be shown to be safe because they might interact with food during processing, storage and the transportation of foodstuffs. Framework Directive 89/109/EEC and its related specific Directives provide this safety basis for the protection of the consumer against inadmissible chemical contamination from food-contact materials. Recently, the European Commission charged an international group of experts to demonstrate that migration modelling can be regarded as a valid and reliable tool to calculate 'reasonable worst-case' migration rates from the most important food-contact plastics into the European Union official food simulants. The paper summarizes the main steps followed to build up and validate a migration estimation model that can be used, for a series of plastic food-contact materials and migrants, for regulatory purposes. Analytical solutions of the diffusion equation in conjunction with an 'upper limit' equation for the migrant diffusion coefficient, D(P), and the use of 'worst case' partitioning coefficients K(P,F) were used in the migration model. The results obtained were then validated, at a confidence level of 95%, by comparison with the available experimental evidence. The successful accomplishment of the goals of this project is reflected by the fact that in Directive 2002/72/EC, the European Commission included the mathematical modelling as an alternative tool to determine migration rates for compliance purposes.


Asunto(s)
Contaminación de Alimentos/legislación & jurisprudencia , Embalaje de Alimentos/legislación & jurisprudencia , Legislación Alimentaria , Modelos Químicos , Plásticos/química , Difusión , Unión Europea , Industria de Alimentos/legislación & jurisprudencia , Humanos
20.
Food Addit Contam ; 15(3): 355-61, 1998 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-9666895

RESUMEN

The paper deals with gel permeation chromatography (GPC) monitoring of the behaviour of PET (polyethylene terephthalate) after repeated extrusions. Virgin PET was submitted to three successive extrusion/drying cycles and then the samples were swelled with hexafluoroisopropanol and treated with chloroform. GPC analysis was carried out at room temperature on a B.C.S. Serial LC 2000 GPC system equipped with a series of four GPC columns with UV detection at 254 nm and chloroform as eluent. GPC results showed that after each extrusion step the molecular weight distribution of the PET was different and Mw, Mn and Mz decreased. These findings suggest that during each extrusion degradation occurs and that repeated extrusions, as in the case of the recycling PET, may cause an alteration of the molecular weight distribution of the original PET.


Asunto(s)
Conservación de los Recursos Naturales , Embalaje de Alimentos , Tereftalatos Polietilenos/química , Cromatografía en Gel , Humanos , Peso Molecular
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