1, extremely neurotoxic: lead can damage the brain and nerves, making people mentally retarded, unresponsive, hyperactive, inattentive, hearing impaired, learning difficulties and dyskinesia.
2, cause anemia
3. Suppress immunity
4, loss of appetite, unexplained abdominal pain, vomiting, diarrhea or defecation.
5, affect the absorption and utilization of minerals and vitamins. Lead to calcium deficiency, zinc deficiency and iron deficiency, etc.
Preserved eggs are foods that many people like to eat, but some of the raw materials for preserved eggs contain lead oxide or salt lead, so the lead content of preserved eggs is much higher than that of fresh duck eggs and salted duck eggs. Children are more sensitive to lead than adults. The absorption rate of lead eaten by adults is 5%-10%, while the absorption rate of children is as high as 50%. In addition, children's brain and nervous system are immature, which makes them more vulnerable to lead and affects their intellectual development. Therefore, parents should not give children more preserved eggs.
Many people like to eat preserved eggs and meat porridge, but it's okay to eat less preserved eggs, but it's bad for your health to eat more.
Because preserved eggs are preserved by mixing soda ash, lime, salt and lead oxide to wrap duck eggs, which contain lead, it may cause lead poisoning if eaten frequently. This will lead to insomnia, inability to concentrate, anemia, joint pain, slow thinking, brain function and other symptoms. In addition, lead will replace calcium, affect calcium intake, and may cause calcium deficiency.
Hygiene and nutrition of preserved eggs
It is often said that preserved eggs can't be eaten. In fact, it is mainly the doubt that preserved eggs contain heavy metal lead, but it is not necessary to be too alarmed, because it can be avoided with a little attention when buying again. Remember to check whether there are black spots of different sizes on the surface of the shell. If there are, avoid eating them.
The key to making preserved eggs is whether the protein in them is completely gelled. Therefore, in the process of making preserved eggs, they must be immersed in a strong alkali solution to achieve the denaturation of protein and produce special flavor and color. However, in order to avoid the deterioration of the finished product caused by re-liquefaction after gelation, lead oxide, copper sulfate and methionine are usually added to the alkali liquor to prevent re-liquefaction. The lead residue that everyone doubts is the residue of this chemical in the eggshell.
Generally speaking, the nutritional value of preserved eggs is: rich in iron, methionine (essential amino acid) and vitamin E (the above is compared with eggs). Disadvantages: protein denatured by alkaline solution is not easy to be absorbed, and LAL(lysinoalanine) in denatured protein has unconfirmed nephropathy in animal experiments.
Personally, preserved eggs can be considered as a food to increase the variety of daily diet and taste special flavor, but it seems that there are other better choices in terms of nutritional value. As for the problem of lead residue, at present, consumers can only judge by their appearance, but I already know that many experts in the food industry have developed a method to maintain the quality of preserved eggs without adding lead oxide by controlling the temperature. I believe that consumers can eat preserved eggs without worrying about heavy metal residues in the near future.