Mineral and nutritional assessments of soybean, buckwheat, spelt, and maize grains grown conventionally and organically

Abstract

The present work determined complete mineral profile of four different types of grains (spelt, soybean, maize, and buckwheat) grown under two growing systems – conventional and organic. The contents of 20 macro-, micro and trace elements were analysed in the examined grains by inductively coupled plasma-optical emission spectrometry (ICP-OES). In most samples, nine elements were present in concentrations higher than 10 mg/kg. The remaining elements were present at lower concentrations or in traces or not detected in certain samples. Aluminium and arsenic, as two toxic elements, were detected only in organic buckwheat grains. Based on the obtained results for the mineral contents, a nutritive assessment of the quality of grains of spelt, soybean, maize, and buckwheat were made. Results of nutritional assessment showed that spelt, soybean, and buckwheat grains could potentially be good sources of several minerals for human diet. On the other hand, the presence of some toxic elements, such as cadmium and strontium, should be monitored. Results of principal component analysis (PCA) and hierarchical cluster analysis (HCA) shown that the mineral composition, to a much greater extent, depended on the botanical origin of grains as compared to the production system.