Castanea sativa shells and fruits: Compositional analysis by proton induced X-ray emission

Chestnut fruits, from Castanea sativa Miller species, have been previously characterized mainly to study the nutritional and biochemical parameters, with mineral contents receiving less attention from the researchers, although these minerals are essential for several mechanisms in human body. In this study, a detailed elemental compositional analysis was performed using Proton Induced X-ray Emission (PIXE) to characterize two varieties of Castanea sativa Miller chestnuts (Longal and Judia). This study comprises the composition of the outer shells (pericarp), inner shells (episperm) and the edible fruits. From our knowledge, this is the first time that the presence of up to 20 elements on the shells and the fruits are reported. Furthermore, by PIXE it was possible to quantify them, allowing significant improvements in the assessment of chestnuts composition. Essential and nonessential elements were quantified on a food item that is used mainly for human consumption but it is also incorporated in animal feeding.