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The content of the micronutrients in consumer eggs
DUŠOVÁ, Hana
The aim of the diploma work was to analyticly verify the actual status of the micronutrients (iodine, copper, zinc and manganese) in consumer eggs. The results of the research gives information about the content of the observed micronutrients in egg yolk and the importance of eggs as a source of these micronutrients for the nutrition of people. The eggs came from 13 small flocks and 7 large flocks in both 2007 and 2008. The average content of iodine in fresh matter of yolk of the eggs from the large flocks in 2007 was 1285,2 {$\pm$} 861,6 {$\mu$}g{$\bullet$}kg-1, zinc 63,71 {$\pm$} 31,08 mg{$\bullet$}kg-1, copper 7,42 {$\pm$} 4,88 mg{$\bullet$}kg-1 and manganese 1,02 {$\pm$} 0,84 mg{$\bullet$}kg-1. The average content of iodine in fresh matter of yolk of the eggs from the small flocks in 2007 was 387,1 {$\pm$} 214,3 {$\mu$}g{$\bullet$}kg-1, Cu 10,90 {$\pm$} 5,28 mg{$\bullet$}kg-1, Zn 73,54 {$\pm$} 44,33 mg{$\bullet$}kg-1 a Mn 1,28 {$\pm$} 0,75 mg{$\bullet$}kg-1. In 2008 the average concentration of iodine in fresh matter of yolk of the eggs from the large flocks was 1071,9 {$\pm$} 543,9 {$\mu$}g{$\bullet$}kg-1, Cu 20,63 {$\pm$} 8,85 mg{$\bullet$}kg-1, Zn 29,59 {$\pm$} 8,67 mg{$\bullet$}kg-1 a Mn 1,42 {$\pm$} 0,62 mg{$\bullet$}kg-1. In 2008 the average concentration of iodine in fresh matter of yolk of the eggs from the small flocks was 340,7 {$\pm$} 330,6 {$\mu$}g{$\bullet$}kg-1, Cu 17,95 {$\pm$} 6,19 mg{$\bullet$}kg-1, Zn 33,10 {$\pm$} 7,97 mg{$\bullet$}kg-1 and Mn 1,22 {$\pm$} 0,54 mg{$\bullet$}kg-1. The Eggs from the large flocks cover 6,8 {--} 13,5% of the daily iodine requirement in adults, 13 {--} 17,3% of copper, only 2,5 {--} 3,1% of zinc and 0,4 {--} 1,1% of manganese. The gained results imply that only the content of iodine in the egg yolk is evidently affected by the intake of it in the feeding rations, the intensity of the egg production and the stage of the laying cycle. The stated relations were not definite with the other elements. The concentration of iodine in the egg yolk was assessed spectrophotometrically by the method of Sandell {--} Kolthoff, modified by Bednář et al., (1964). The content of zinc, manganese and copper in the egg yolk were assessed by the method of atomic absorption spectroscopy (AAS).
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