Comparison of Heavy Metal Intake by Different Species of the Genus Allium L

Abstract

Allium vegetables belong to the most widespread and commonly grown vegetables in Slovakia. In this study, we dealt with the content of selected heavy metals (Zn, Mn, Cr, Cu, Ni, Pb, and Cd) in cultivated garlic (Záhorský, Lukan, Makoi), onion (Amika, Red Matte, Diamant), and leek (Bavaria, Golem, Tango). We determined the total content of heavy metals (aqua regia), and available-mobile forms of heavy metals (1 M NH₄NO₃) in soils. Analytical final procedure was flame AAS. The results were compared with the limit values given by the Law no. 220/2004 (valid in the SR) as well as threshold values proposed by the European Commission (EC) (2006). Gained result showed that the total content of Cd (1.26 mg.kg^-1) as well as the available mobile forms of Cd (0.16 mg.kg^-1) and Pb (0.64 mg.kg^-1) was exceeded on the soil on which Allium species were grown. Determined contents of heavy metals in garlic were in the range of 0.03-0.07 mg Cd.kg^-1 FM (fresh matter), 0.02-0.11 mg Pb.kg^-1 FM (fresh matter), in onion ranged from ND (not detected) to 0.03 mg Cd.kg^-1 FM (fresh matter), 0.09-0.2 mg Pb.kg^-1 FM (fresh matter), and in leek were in the range of, 0.07-0.13 mg Cd.kg^-1 FM (fresh matter), and 0.3-0.5 mg Pb.kg^-1 FM (fresh matter). Based on the obtained BAF values, we can conclude that the genus Allium does not belong to the accumulator of evaluated hazardous metals. Safe food production requires constant monitoring of hazardous metals in raw materials of plant origin, as these metals can have serious negative effects on human health.

Keywords: Allium; Garlic; Heavy metals; Leek; Onion.