Biogenic and Risk Elements in Walnuts (Juglans regia L.) from Chosen Localities of Slovakia

Abstract

Walnuts (fruits Juglans regia, L.) belong among to the most spread, commercially grown tree nuts in the world. Nuts have grown higher attention in last years as valuable sources of essential elements; they are rich in non-essential fatty acids, proteins, fibre, plant sterols and minerals including potassium and magnesium and antioxidants. Determination of elements distribution in nuts is required not only for evaluation of total intake of essential elements in our food, but it is also useful for gaining data on contamination of foodstuffs by risk elements, but also for monitoring of heavy metal contamination in foodstuffs. Walnut samples were taken from three selected areas in Slovakia. The first location is in the vicinity of the cities Strážske, Humenné and Vranov nad Topľou, the second one is situated close to the city of Prievidza and the last one is close to the city of Vráble. The results of evaluation showed that the content of the elements monitored in location of Vráble did not exceed the limits set by the Regulation of Ministry of Health of Slovak Republic No 2/1994. In the half of samples taken from the location of Strážske, higher content of cadmium as the permitted limit has been found. The samples exceeded the amounts allowed by the Regulation No 2/1994 in contaminated area called “The dangerous triangle”. Potential consumption of these walnuts could negatively affect human organism, but only if the kernels from the exact locality would be consumed in very high daily amounts (100-fold higher intake as daily intake according to the Statistical Office of SR).