Copper, zinc, iron and manganese content in edible parts of some fresh vegetables sold on markets in Poznań

Abstract

Copper, zinc, iron and manganese contents were determined in edible parts of some fresh vegetables sold on markets in Poznan. The copper and zinc contents in vegetables obtained in the present study were compared to the ones reported from an analogous study carried out in the Department of Horticultural Plant Fertilization in Poznan fifteen years ago. Samples of vegetables were collected from six points distributed in the area of Poznan from March to July at monthly intervals. For the study, vegetables were divided into three groups according to edible parts: leaves (lettuce, cabbage, parsley, leek), roots (carrot, celeriac, parsley) and fruits (tomato, cucumber). The concentration of copper, zinc, iron and manganese was determined by the atomic flame absorption method using an AAS 3 Zeiss apparatus. The highest content of copper was found in roots of celeriac, while the smallest content was shown in cabbage leaves. The highest mean content of zinc was found in lettuce leaves and the lowest one in tomato fruit. The mean content of copper in all the vegetable species was lower in 2005 than in 1993. In 1993 more zinc was found in vegetables whose edible parts were fruits compared to the results of 2005. The vegetables whose leaves and roots are eaten were characterized by a higher zinc content in 2005. The highest content of iron was found in leaves of leek, while the lowest amounts were determined in tomato and cucumber fruits. The highest mean content of manganese was found in leaves of lettuce, while the smallest amount was in carrot roots. The iron content in the vegetables whose leaves and fruits are edible parts was lower in 2005 than in 1993, while the root vegetables were characterized by more iron in 2005. Higher content of manganese in all the vegetable species examined was found in 1993 than in 2005.