Evaluation of the microelement profile of Turkish hazelnut (Corylus avellana L.) varieties for human nutrition and health

In this study, the levels of boron (B), cobalt (Co), copper (Cu), chromium (Cr), iron (Fe), lithium (Li), nickel (Ni), selenium (Se) and zinc (Zn) microelements in 16 hazelnut samples were determined by inductively coupled plasma mass spectrometry and atomic absorption spectroscopy after microwave digestion, and are discussed for human nutrition and health. Significant differences were observed between the microelement contents of the 16 varieties (P < 0.01). The average microelements concentrations in the varieties varied in the following ranges: B, 13.63–23.87; Co, 0.47–0.82; Cr, 0.22–0.52; Cu, 16.23–32.23; Fe, 31.60–51.60; Li, 0.035–0.042; Ni, 0.58–2.58; Se, 0.96–1.39; and Zn, 22.03–44.03 mg/kg. These results showed that hazelnuts can be an important microelement source for human nutrition and health. According to our trace element data, a daily consumption of 50 g hazelnut can supply easily about 6% for B, 9% for Co, 19% for Fe, 9% for Ni and 16% for Zn of the recommended daily allowance. On the other hand, Se, Cu and Cr levels of 50 g hazelnuts are higher than the respective daily requirements, but slight overdoses of these elements are non-toxic for human health.