Risk of cadmium and lead transfer from the soil into seeds of chosen minor plants / Ryzyko migracji kadmu i ołowiu z gleby do nasion wybranych roślin rzadkich

The risk of Cd and Pb transfer from the soil into the seeds of different cultivars of buckwheat, amaranth and quinoa cultivated in field trial was investigated. Five cultivars from each pseudocereal, that is, buckwheat (Špačinská, Siva, Bamby, Aiva, Madawska), amaranth (Golden Giant, Rawa, Annapurna, Oscar Blanco, Koniz) and quinoa (Temuco, Quinua, Yulai, Carmen, Ccankolla) were analysed. Content of risky metals in soil and pseudocereal seeds was assessed by AAS. Pseudototal contents of metals determined in the soil extract by aqua regia were lower than the limit values given by Law No. 220/2004 with exception of Cd (the soil content was 40% higher than the hygienic limit). Contents of bioavailable forms determined in the soil extract by NH4NO3 (c = 1 mol • dm^-3) of all observed metals with exception of Pb were lower than hygienic limits. The determined content of bioavailable Pb forms was 2.3-fold higher than the hygienic limit. The limit value for Cd content was not exceeded in any buckwheat cultivar. The determined Pb content was in cv. Bamby at the level of hygienic limit, and in cv. Madawska twofold higher than the limit given by Foodstuff Codex of the Slovak Republic (FC SR). On the other hand, in seeds of nearly all the investigated amaranth and quinoa cultivars, higher Cd and Pb contents than the maximal allowed amounts in cereals according to FC SR were determined. The presented results indicate the serious risk of Cd and Pb accumulation by seeds of minor plants which are utilised in the production of functional foods.