Trace element content in market eggs in Bohemia

Abstract

The aim of this study was to analytically determine the content of iodine, copper, zinc and manganese in the yolk of consumer eggs in Bohemia in 2007 and 2008. Investigated eggs originated from six so called intensive farms with large flocks (118 eggs) and twelve backyard farms or small-flock establishments (136 eggs) from three administrative regions in Czech Republic. Eggs from intensive farms were obtained directly from the establishments, while eggs from backyard farms were purchased from private farmers. Spectrophotometric Sandell-Kolthoff method was used for determination of iodine content in egg yolk, while Cu, Zn and Mn levels were determined by the flame absorption spectrophotometric method (AAS). The average content in fresh egg yolk from intensive farms was determined to 0.9 ± 0.2 for iodine, 8.4 ± 2.1 of copper, 29.8 ± 6.9 of zinc and 1.2 ± 0.3 of manganese, all in mg·kg−1, as compared to yolk content from backyard farms with 0.4 ± 0.04 mg·kg−1 of iodine, 10.8 ± 2.9 of copper, 32.5 ± 6.9 of zinc and 1.5 ± 0.3 of manganese. Average content of copper, zinc and manganese was lower in egg yolks from intensive farms (P < 0.01) as compared to the egg yolks from backyard farms, while iodine content on the other hand was lower in eggs from backyard farms (P < 0.01).

Keywords

• egg yolk
• iodine
• copper
• zinc
• manganese