Bioavailability of iron in the regional basic diet (RBD) with dietary supplement in Brazil.

The consumption of the regional basic diet (RBD) determines a state of malnutrition found in the low-income population of Northeastern Brazil. A dietary supplement known as multimixture has been used as an alternative source of iron in food for the prevention and/or treatment of anemia and for the recovery from malnutrition. The purpose of the present work was to evaluate the bioavailability of iron in the RBD supplemented with multimixture in iron-depleted and non-depleted Wistar rats. To produce iron depletion in the animals, pretest depletion diets without iron and the pretest control diet based on the AIN-93 diet were used for 8 weeks. This phase was followed by the test diets: control, AIN-93 extrinsically labeled with (59)FeCl(3); RBD, containing carioca beans intrinsically labeled with (59)Fe; and RBDMM, RBD plus multimixture, supplied in a single meal. Hemoglobin concentration, weight gain, and dietary intake were determined in the pretest phase. Iron bioavailability was determined by the determination of total-body radiation in the animals for 7 days, using a solid scintillation detector. The hemoglobin concentration, weight gain, and dietary intake were greater in the non-depleted animals than in the iron-depleted ones. The iron bioavailability of the diets did not differ significantly. It was concluded that the multimixture did not affect the bioavailability of Fe contained in the beans of the RBD.

Comparison of metal analysis in sediments using EDXRF and ICP-OES with the HCl and Tessie extraction methods.

The work presents an investigation on metal availability in sediments during 13 months using the dispersive-energy X-ray fluorescence (EDXRF) and atomic emission spectrometry with induced argon plasma (ICP-OES) techniques and single extraction (0.1moll(-1) HCl) and Tessie's sequential speciation methods. The EDXRF technique could yield essentially the same profile as ICP-OES for the seasonal variation of metals in sediments, but in a more practical way. The sequential extraction procedure (SEP) was more efficient in metal dissolution than single extraction. The Pb, Ni, Al, Cr, and Fe elements were less efficiently extracted with single extraction in relation to sequential extraction. For Co both methodologies were equivalent, but for Cu and Mn the extraction was higher with single extraction. Single extraction does not mobilize Pb, Ni, Al, Cr, and Fe adsorbed on oxides and bound to organic matter. However for Cu and Mn, not only extracted these metals from the four fractions, but it also dissolved part of the fifth fraction (residual). Principal Component Analysis discriminated seasonal variations in the content of several metals, mainly Fe, Co, Ni, and Zn. The mobility of metallic ions in the sediments is conditioned to the seasonal flow of organic and inorganic material coming from the river or by the erosion of adjacent soils.