Comparisons Of Copper,Chromium,Manganese,Iron,Calcium And Magnesium Contents In Three Kinds Of Eggs On The Market

This study examined and analyzed the content of six elements in ordinary eggs,chai eggs and dark eggs,to provide theoretical and practical reference for scientific research on animal husbandry and food science and people's choice of consumption.The experimental samples were 3 kinds of fresh eggs(ordinary eggs,chai eggs and dark eggs)with a similar production date which were bought from a supermarket in Tianjin.40 eggs were randomly selected from each kind of the eggs.The contents of copper,chromium,manganese,iron,calcium and magnesium in egg samples were determined by atomic absorption spectrometry.1.A comparative study on the contents of copper,chromium,manganese and iron in three kinds of eggs.(1)Comparison and analysis of contents of trace elements copper,chromium,manganese and iron in whole egg.The amount of copper in whole eggs ranged from high to low: dark eggs>ordinary eggs>chai eggs,the difference in copper content among the three kinds of eggs was not significant(P>0.05);the amount of chromium in whole eggs ranged from high to low:ordinary eggs>chai eggs>dark eggs.The difference was not significant(P>0.05);the amount of manganese in whole eggs ranged from high to low: dark eggs>ordinary eggs>chai eggs.The difference was not significant(P>0.05);the amount of iron in whole eggs ranged from high to low: dark eggs>chai eggs>ordinary eggs.The content of iron in dark eggs and chai eggs is significantly higher than that in the ordinary eggs(P<0.05).And there was no significant difference in iron content between the dark eggs and chai eggs(P>0.05).(2)Comparison and analysis of contents of trace elements copper,chromium,manganese and iron in the egg yolk.The amount of copper in the egg yolks ranged from high to low: ordinary eggs>chai eggs>dark eggs,the highest content of copper in ordinary eggs yolks was 2.13 mg/kg,and the content of copper in ordinary eggs yolks and chai eggs yolks was significantly higher than that in dark eggs yolks(P<0.05),and different between the ordinary eggs yolks and chai eggs yolks about the content of copper was not significantly(P>0.05);The amount of chromium in the egg yolks ranged from high to low: ordinary eggs>chai eggs>dark eggs,and the chromium content in ordinary eggs yolks was significantly higher than that in chai eggs yolks and dark eggs yolks(P<0.05),while the different between chai eggs yolks and dark eggsyolks was not significant about the content of chromium(P>0.05);The amount of manganese in the egg yolks ranged from high to low: dark eggs>chai eggs>ordinary eggs.The content of manganese in dark eggs yolks was significantly higher than that in ordinary eggs yolks(P<0.05).And there was no significant difference between the dark and the chai eggs yolks(P>0.05).There was no significant difference between chai and ordinary eggs yolks(P>0.05).The amount of iron in the egg yolks ranged from high to low: chai eggs>dark eggs>ordinary eggs,and the difference was not significant(P>0.05).2.Comparison and analysis of the contents of calcium and magnesium in three kinds of eggs.(1)Comparison and analysis of the contents of calcium and magnesium in whole eggThe amount of calcium in whole eggs ranged from high to low: ordinary eggs>chai eggs>dark eggs,the different between ordinary eggs and dark eggs was significant(P<0.05),and the calcium content in chai eggs and dark eggs had significant differences(P<0.05),There was no significant difference in calcium content between normal and chai eggs(P>0.05).The amount of magnesium in whole eggs ranged from high to low: ordinary eggs>dark eggs>chai eggs,and there was no significant difference in magnesium content among the three groups(P>0.05).(2)Comparison and analysis of the content of calcium and magnesium in egg yolks.The amount of calcium in whole egg yolks ranged from high to low: ordinary eggs>chai eggs>dark eggs,and the calcium content in ordinary and chai eggs yolks was significantly higher than that of dark eggs yolks(P<0.05).While there was no significant different about the content of calcium in the ordinary and the chai eggs yolks(P>0.05).The amount of magnesium in egg yolks ranged from high to low: chai eggs>ordinary eggs>dark eggs,and there was no significant difference about magnesium content among the three groups(P>0.05).These studies show that the three commercially available egg are rich in copper,chromium,manganese,iron,calcium,and magnesium.Among them,copper,chromium,manganese,iron,and calcium are mainly found in egg yolks,and the content of magnesium in the whole egg is higher than in the egg yolk,suggesting that magnesium is mainly distributed in egg whites.The content of iron in dark eggs and chai eggs was significantly higher than that in ordinary eggs in whole eggs.The content of copper in ordinary eggs and chai eggs wassignificantly higher than that in dark eggs.The chromium content in ordinary eggs yolks was significantly higher than that in chai and dark eggs yolks.The content of manganese in dark eggs yolks was significantly higher than that in ordinary eggs yolks,and the calcium content in the ordinary eggs and chai eggs were significantly higher than dark eggs whether about the whole eggs or the egg yolks.This study provides people's egg consumption,especially the demand of specific population for trace elements with important theoretical and practical basis.