RESUMEN

The effect of the number of pesticide residue values below the LOQ/LOD of analytical methods, the variability of residues in individual fruits, mass of fruit units and the number of bootstrap iterations was studied on the probabilistically estimated acute exposure of consumers. The 4720 daily apple consumption data and the results of 1239 apple sample analyses for captan residues, performed within the Hungarian monitoring programme between 2005 and 2011, were used in this study as model matrix. Up to about 95th percentile exposure (µg/(kg bw·day)), simply multiplying each residue in composite samples with each consumption value gave similar estimates to those obtained with the complex procedure taking also into account the mass of and residues in individual fruits. However, the exposure above the 95th percentile calculated with the complex procedure gradually increased with increasing percentile level compared to the simple procedure. Including the high number of non-detects reduced the estimated exposure, which was the highest when only the residues measured in treated fruits were taken into account. The number of bootstrap iterations between 100 and 10,000 did not significantly affect the calculated exposure. The 99.99th percentile exposure amounted to 17.9% of the acute reference dose of 300 µg/(kg bw·day) for women of childbearing age.

Asunto(s)

Captano/administración & dosificación , Dieta , Exposición a Riesgos Ambientales , Fungicidas Industriales/administración & dosificación , Malus , Probabilidad , Humanos , Hungría , Límite de Detección

RESUMEN

Poppy seed-containing foods are popular dishes in Hungary and some other Central European countries. The alkaloids of poppy are used in the production of medicines. Poppy seeds used as food may also contain considerable amounts of alkaloids, which raises the question of food safety. Morphine, codeine, thebaine and noscapine concentrations of poppy seed samples from the period 2001-2010 and consumption data from two Hungarian surveys, carried out in 2003 and 2009, were evaluated. Exposure calculations were made for morphine intake by both point estimate and probabilistic methods, and the uncertainty of the calculated values was estimated. The point estimate for the acute consumer exposure, calculated using the 97.5th percentiles of morphine concentration and of poppy seed consumption and taking into account the reduction of morphine content by processing, was 78.64 µg (kg bw)⁻¹ day⁻¹ for adults, and 116.90 µg (kg bw)⁻¹ day⁻¹ for children. Based on probabilistic estimations, the 97.5th and 99th percentile exposures ranged between 18.3-25.4 and 25.6-47.4 µg (kg bw)⁻¹ day⁻¹ for adults, and between 32.9 and 66.4 µg (kg bw)⁻¹ day⁻¹ for children, respectively. As a no observed effect level (NOEL) had not been established, the significance of exposure could not be assessed.

Asunto(s)

Dieta/efectos adversos , Morfina/administración & dosificación , Morfina/análisis , Narcóticos/administración & dosificación , Narcóticos/análisis , Papaver/química , Semillas/química , Adulto , Niño , Codeína/análisis , Dieta/etnología , Dieta/tendencias , Registros de Dieta , Femenino , Análisis de los Alimentos , Manipulación de Alimentos , Humanos , Hungría , Lactante , Masculino , Modelos Biológicos , Morfina/efectos adversos , Narcóticos/efectos adversos , Noscapina/análisis , Papaver/efectos adversos , Medición de Riesgo/métodos , Semillas/efectos adversos , Tebaína/análisis

RESUMEN

In view of the frequent occurrence of mycotoxins in cereals, a study was initiated to assess the exposure of the Hungarian adult population. Consumption data for 1360 individuals, based on a 3-day questionnaire, indicated that white bread accounted for the major intake of cereal-based products. Various cereal products were analysed for 16 mycotoxins by a LC/MS/MS multi-toxin method with LOD of 16 µg kg⁻¹ and LOQ of 50 µg kg⁻¹. Deoxynivalenol (DON) was most frequently detected, but no acetyl-deoxynivalenol was present in detectable concentrations. Consumer exposure was calculated with standard Monte Carlo probabilistic modelling and point estimates, taking into account bread consumption and DON contamination in independently taken wheat flour and wheat grain samples. Over 55% of cases the DON intake were below 15% of the provisional maximum tolerable daily intake (PMTDI) of 1 µg/(kg bw)/day. However, in 5-15% of cases, the intake from bread consumption alone exceeded the PMTDI. Wheat grain data led to the higher percentage. Intakes estimated from both data sets were at or below the acute reference dose (ARfD) of 8 µg/(kg bw)/day in 99.94-99.97% of cases.

Asunto(s)

Pan , Contaminación de Alimentos , Micotoxinas/administración & dosificación , Tricotecenos/administración & dosificación , Adulto , Algoritmos , Pan/análisis , Dieta , Grano Comestible/química , Femenino , Harina/análisis , Humanos , Hungría , Límite de Detección , Masculino , Método de Montecarlo , Micotoxinas/análisis , Encuestas Nutricionales , Reproducibilidad de los Resultados , Tricotecenos/análisis , Triticum/química

RESUMEN

Substrate structural mapping suggests that the catalytic site of cellobiose dehydrogenase from Phanerochaete chrysosporium forms a narrow cave with two hexose binding subsites. Kinetic data also show that beta-di or oligosaccharides are favored electron donors with respect to both KM and kcat. Surprisingly, thiocellobiose showed an even higher kcat than cellobiose, although the KM value was somewhat higher. The CDH was purified using an updated protocol.

Asunto(s)

Basidiomycota/enzimología , Deshidrogenasas de Carbohidratos/metabolismo , Sitios de Unión , Deshidrogenasas de Carbohidratos/aislamiento & purificación , Cinética , Oxidación-Reducción , Especificidad por Sustrato

RESUMEN

The cDNA of cellobiose dehydrogenase (CDH) from Phanerochaete chrysosporium has been cloned and sequenced. The 5' end was obtained by PCR amplification. The cDNA contains 2310 translated bases excluding the poly(A) tail. The deduced mature protein contains 770 amino acid residues and is preceded by a 18 residue long signal peptide. The regions of the amino acid sequence corresponding to the heme and FAD domains of CDH were identified as well as the nucleotide-binding motif, the disulfide pairing and a methionine residue chelating the heme iron. No homologous sequences were found for the heme domain, however, the FAD domain appears to be distantly related to the GMC oxidoreductase family.

Asunto(s)

Basidiomycota/genética , Deshidrogenasas de Carbohidratos/genética , Genes Fúngicos/genética , Secuencia de Aminoácidos , Aminoácidos/análisis , Secuencia de Bases , Basidiomycota/enzimología , Deshidrogenasas de Carbohidratos/química , Deshidrogenasas de Carbohidratos/aislamiento & purificación , Clonación Molecular , ADN Complementario/genética , ADN de Hongos/genética , Flavina-Adenina Dinucleótido , Hemo , Datos de Secuencia Molecular , Alineación de Secuencia , Análisis de Secuencia de ADN