MINERAL COMPOSITION OF TREE NUTS AND SEEDS

A growing interest has been observed globally over the last decade in nuts and seeds as significant ingredients of everyday diet. The consumption of nuts and seeds has been on the increase. A daily intake of 1 ounce (similar to 28 g) of nuts and seeds has been suggested as part of a balanced diet. Many investigations have confirmed that lipids of nuts and seeds exert a positive impact on the cardiovascular system, are beneficial to the blood glucose level, and may contribute to prevention of some types of cancer. The aim of this study was to determine content of selected macro- and micronutrients as well as toxic trace elements in nuts and seeds. The concentrations of Na, K and Ca were determined with the atomic emission spectrometry method (FEAS), while those of Mg, Fe and Zn were measured with the method of atomic absorption spectrometry (FAAS). The levels of lead, cadmium and arsenic were determined with the method of graphite furnace atomic absorption spectrometry (GF-AAS). The highest content of magnesium was determined in Brazilian nuts, zinc in pumpkin seeds and iron in cashew nuts. Raw nuts and seeds were characterized by a low content of sodium and a high content of potassium, which is especially beneficial to human health. Nuts and seeds originating from Ethiopia and Hungary had the lowest content of lead and cadmium but the highest content of arsenic, compared with products from other countries. The highest amounts of cadmium and lead were determined in macadamia nuts, whereas the lowest ones were in pumpkin seeds. The content of arsenic was low and did not depend on a species. However, the content of toxic trace elements was correlated with the fat and protein content.