Elemental characterization of bread and durum wheat by instrumental neutron activation analysis

Cereals are by far the most significant agricultural crops, not only due to the sheer amount of their gross-tonnage production and prevalence in human diets worldwide, but also as food vehicles of important items for human nutrition and wellness at large—proteins, dietary fibers and oligoelements, such as selenium, calcium, zinc and iron, to name just a few. Still, some micronutrients feature an uneven distribution in the upper continental crust, and thus in cultivation soils deriving therefrom. Whether soils have always been poor in an essential element, or have just become deprived of it by intensive farming, the result is the same: insufficient soil–plant transfer, feeble-to-nonexistent plant uptake, and, therefore, unsatisfactory dietary distribution of that element through the food chain. Countries that implemented corrective measures or programs of crop biofortification and consumer education have been successful in dealing with some micronutrients’ deficiencies. Given their relative weight in Portuguese diets, cereals are obvious candidates for crop-supplementation strategies that may contribute to an upgrade in the health status of the whole population. A good knowledge of element-baseline data for major cereal varieties (plants) and main production areas (soils) is a pre-requisite though. The present work was aimed at an elemental characterization of cereals and soils from relevant wheat-producing areas of mainland Portugal. This paper is focused on wheat samples—bread and durum wheats; Triticum aestivum L. (Farak and Jordão cultivars) and Triticum durum Desf. (Don Duro and Simeto cultivars), respectively—from the 2009 campaign, collected at Trás-os-Montes, Alto Alentejo and Baixo Alentejo (inland regions). Elemental concentrations were determined by instrumental neutron activation analysis (INAA; k0-variant), and assessed with the k0-IAEA software. Quality control was asserted through the analysis of NIST-SRM® 1567a (Wheat Flour), NIST-SRM® 1568a (Rice Flour) and GBW 07404 (Limy-yellow Soil). Results are discussed and compared to available data from abroad.