Estudio de los componentes bociogenos tiocianogenéticos presentes en alimentos de consumo habitual en zonas de la Alpujarra granadina

Se ha realizado un control del SCN- liberado por acción enzimática en alimentos vegetales del género Brasica y otras crucíferas en las que se encuentran glucósidos tiocianogenéticos. El análisis cuantitativo se realiza mediante la formación del complejo Fe(SCN)2+ y lectura espectrofotométrica a 460 nm. Los valores de SCN- encontrados en diversas especies del género Brasica (coles, coliflores, etc.) son del orden de 22 mg% referidos a muestra seca.A study has been carried out of the SCN- levels freed by enzymatic ac tion, in food vegetables of the Brassica and other cruciferae, in which thiocianogenetic glucosides are found. The quantitative analysis was done by means of the formation of the com plex Fe(SCN)2+ and taking a spectrophotometric reading at 460 nm. The SCN- values found in different species of the Brassica family (cab bage, cauliflower, etc.) are in the order of 22% mg, read in a dry sample

Xenoestrogens released from lacquer coatings in food cans

We present data showing that some foods preserved in lacquer-coated cans and the liquid in them may acquire estrogenic activity. Hormonal activity was measured using the E-screen bioassay. The biological activity of vegetables packed in cans was a result of plastic monomers used in manufacturing the containers. The plastic monomer bisphenol-A, identified by mass spectrometry, was found as a contaminant not only in the liquid of the preserved vegetables but also in water autoclaved in the cans. The amount of bisphenol-A in the extracts accounted for all the hormonal activity measured. Although the presence of other xenoestrogens cannot be ruled out, it is apparent that all estrogenic activity in these cans was due to bisphenol-A leached from the lacquer coating. The use of plastic in food-packaging materials may require closer scrutiny to determine whether epoxy resins and polycarbonates contribute to human exposure to xenoestrogens.This work was supported by grant 94/1551 from the Fondo de Investigaciones Sanitarias (FIS), Spanish Ministry of Health

Español

Se ha realizado una puesta a punto y estudio comparativo de los métodos analíticos propuestos por la legislación española para la determinación de ión nitrato en aguas potables y el método ionométrico que utiliza electrodo selectivo de nitratos. El resultado de este estudio es favorable a la utilización del método ionométrico al ser más preciso y de mayor fiabilidad.A comparative study has been made between methods for deterrnjning the presence of N03- in drinking water, that proposed by Spanish legislation, and the ionornetric rnethod which uses a selective nitrate electrode. The result of this study ours the use of the ionometric method as being the most precise and of greater reliability

Determinación de nitratos en aguas de bebida en la provincia de Granada

A study has been carried on of the nitrate levels in the drinking water of 107 villages. in Granada province. The samples are grouped according to a water supplys's basin. The methods recommended by the Spanish legislation were followed and compared with the ionometric method. All samples have a good concentration of nitrates.Se ha realizado un estudio de los niveles de nitratos en las aguas de bebida de 107 poblaciones de la provincia de Granada agrupadas de acuerdo con la cuenca de abastecimiento. Se han seguido los métodos espectrofotométricos recomendados por la legislación española, comparándolos con un método ionométrico. Todas las muestras presentan niveles aceptables de nitratos

Estudio de los componentes bociogenos tiocianogenéticos presentes en alimentos de consumo habitual en zonas de la Alpujarra granadina

A study has been carried out of the SCN- levels freed by enzymatic action, in food vegetables of the Brassica and other cruciferae, in which thiocianogenetic glucosides are found. The quantitative analysis was done by means of the formation of the complex Fe(SCN)2+ and taking a spectrophotometric reading at 460 nm. The SCN- values found in different species of the Brassica family (cabbage, cauliflower, etc.) are in the order of 22% mg, read in a dry sample.Se ha realizado un control del SCN- liberado por acción enzimática en alimentos vegetales del género Brasica y otras crucíferas en las que se encuentran glucósidos tiocianogenéticos. El análisis cuantitativo se realiza mediante la formación del complejo Fe(SCN)2+ y lectura espectrofotométrica a 460 nm. Los valores de SCN- encontrados en diversas especies del género Brasica (coles, coliflores, etc.) son del orden de 22 mg% referidos a muestra seca

Método espectrofotométrico para la determinación de tiosoles de bajo peso molecular

A spectrophotometric method has been developed for the determination of low molecular weight thiols with sodium nitroprusside and in presence of a soluble salt of zinc. It is compared the results using water and formamide as solvents.Se ha establecido un método espectrofotométrico para la determinación de tioles de bajo peso molecular con nitroprusiato sódico y en presencia de una sal soluble de cinc. Se comparan los resultados obtenidos al utilizar agua y formamida como disolventes

The E-SCREEN assay as a tool to identify estrogens: an update on estrogenic environmental pollutants.

Estrogens are defined by their ability to induce the proliferation of cells of the female genital tract. The wide chemical diversity of estrogenic compounds precludes an accurate prediction of estrogenic activity on the basis of chemical structure. Rodent bioassays are not suited for the large-scale screening of chemicals before their release into the environment because of their cost, complexity, and ethical concerns. The E-SCREEN assay was developed to assess the estrogenicity of environmental chemicals using the proliferative effect of estrogens on their target cells as an end point. This quantitative assay compares the cell number achieved by similar inocula of MCF-7 cells in the absence of estrogens (negative control) and in the presence of 17 beta-estradiol (positive control) and a range of concentrations of chemicals suspected to be estrogenic. Among the compounds tested, several "new" estrogens were found; alkylphenols, phthalates, some PCB congeners and hydroxylated PCBs, and the insecticides dieldrin, endosulfan, and toxaphene were estrogenic by the E-SCREEN assay. In addition, these compounds competed with estradiol for binding to the estrogen receptor and increased the levels of progesterone receptor and pS2 in MCF-7 cells, as expected from estrogen mimics. Recombinant human growth factors (bFGF, EGF, IGF-1) and insulin did not increase in cell yields. The aims of the work summarized in this paper were a) to validate the E-SCREEN assay; b) to screen a variety of chemicals present in the environment to identify those that may be causing reproductive effects in wildlife and humans; c) to assess whether environmental estrogens may act cumulatively; and finally d) to discuss the reliability of this and other assays to screen chemicals for their estrogenicity before they are released into the environment