Do preserved eggs contain a lot of lead? What are the effects of eating too much?

Preserved eggs contain a large amount of lead, in September 2008, China from the perspective of food quality and safety, the new revision of the lead content standards of preserved eggs, deleted the original preserved egg standards in the traditional lead-containing processing technology. In the new standard, the lead content of preserved eggs has been strictly regulated - no more than milligrams of kilograms, which is much lower than the 2 milligrams of lead content required in the original "Hygienic Standards for Egg Products".

Now the commonly said lead-free process is no longer the use of lead-containing raw materials, but does not mean that the preserved eggs are completely lead-free, because the atmosphere, water flow and soil inevitably contain a certain amount of lead, so even if the lead-free process made of preserved eggs may also contain lead, and in addition to lead, preserved eggs often contain heavy metals such as zinc and mercury, and children have a strong ability to absorb heavy metals, so the harm caused is relatively large.

If preserved eggs are eaten regularly, they can cause lead poisoning.

This can lead to symptoms such as insomnia, inability to concentrate, anemia, joint pain, slow thinking, and impaired brain function. In addition, lead can replace calcium, affecting calcium intake and possibly resulting in calcium deficiency.

Suggestion: When eating Songhua eggs, add a little aged vinegar, vinegar can sterilize, and can neutralize part of the alkalinity of Songhua eggs, and it tastes more delicious.

Preserved eggs contain a lot of lead, which is harmful to eat more, and can be beautiful if you eat less!

Preserved eggs contain lead.

Zhu Yi, an associate professor at the College of Food Science and Nutritional Engineering of China Agricultural University, confirmed that the lead-free process means that no lead compounds are used in the processing of preserved eggs, and lead-free preserved eggs do not mean that preserved eggs are completely lead-free. Because in the natural world we live in, the air, soil, and water will contain trace amounts of lead, and it is almost impossible to make preserved eggs absolutely lead-free.

It can be seen that preserved eggs contain lead and should not be eaten excessively.

Inspection method: a check: put the preserved eggs in the palm of the hand, the good quality preserved eggs are elastic, the trembling is large, and the quality of the non-fluttering preserved eggs is poor.

Second shake: pinch the preserved egg and shake it in your ear a few times, listen to whether there is a sound of water, good preserved eggs generally have no sound, and the louder the sound, the more likely the preserved eggs have been broken.

Three looks: the shell of the preserved egg is gray-white, and there are no black spots for the top grade. When viewed under the light, most of the eggs are black or brown, and a small part is yellow or light red. If most or all of the eggs are brown and clear, and there are blister shadows that rotate back and forth, it is an inferior egg.

Four tastes: If the preserved egg is marinated well, the egg white is elastic, brown, and has a pine branch pattern, and the center of the egg yolk is orange-red.

Eat less.

Preserved eggs contain too much lead, and long-term consumption of large amounts may lead to anemia, high blood pressure, kidney damage, etc., and will also cause miscarriage, premature birth, baby malformations, and affect children's intellectual development.

3. Do lead-free preserved eggs contain lead?

Lead-free preserved eggs also contain lead, but the lead content has been greatly reduced, and the lead content of lead-free preserved eggs that meet the national standard is similar to the lead content of meat products, tofu, fish, etc. that we eat daily, and even lower than some vegetable products, fruit products and fungi.

4. Who should not eat preserved eggs?

1. The sodium content in preserved eggs is high, and patients with high blood pressure and pregnant women who are prone to gestational hypertension should not eat preserved eggs.

2.Children are more sensitive to lead, and young children in the developing period should not eat preserved eggs.

3.After preserved eggs are processed, the vitamin A content decreases, and B vitamins are lost a lot. The elderly have a small amount of food, weak digestion ability, and eat preserved eggs, which cannot meet their nutritional needs.

5. Warm tips.

After inspection and analysis, there are 400-500 bacteria attached to the clean preserved eggs, and up to 100 million-400 million bacteria on the dirty Songhua egg shells. Therefore, when buying preserved eggs, it should be noted that if the egg white is light green, the toughness is poor, and it is easy to loosen, such preserved eggs must not be eaten.

Preserved eggs should not be overdosed on lead, if the money is excessive, he will not let them be sold, and now there are preserved eggs sold in supermarkets and online.

Although he signed too much, it did not exceed the safety standards for use, and it was liked by many people.

The lead content of preserved eggs is generally not overweight, so there is no need to prohibit it.

The "national standard" GB T9694-2014 issued by the General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China and the Standardization Administration of the People's Republic of China stipulates that the lead content of preserved eggs shall not be greater than milligrams and kilograms. The implementation of the new national standard announced the end of the lead process of preserved eggs, and in the future, preserved eggs will need to be produced by lead-free process, which will improve the safety of preserved eggs to a new level.

Lead and its compounds are harmful to humans. Frequent consumption of foods containing excessive lead leads to the accumulation of lead in the human body, which is harmful to the human nervous system, immune system, kidneys, etc.

First of all, quicklime reacts with water to produce mature lime, and then slaked lime metathesis reacts with potassium carbonate, the main component of soda ash and plant ash, to generate strong alkalis NaOH and KOH. The chemical equation of the reaction is: cao+h2o=ca(oh)2ca(oh)2+na2co3=caco3 +2naohca(oh)2+k2co3=caco3 +2kohnaoh, koh penetrates into the egg white and egg yolk through the eggshell, and reacts with the protein in it, resulting in protein hydrolysis, coagulation and release of a small amount of hydrogen sulfide gas.

At the same time, the infiltrated alkali will further neutralize with the amino acids, the products of protein hydrolysis, and the crystals of the resulting salts are deposited in the preserved egg whites of the gel peptides, and "pine flowers" appear (which is why the pine flower eggs get their name). The hydrogen sulfide gas reacts with the minerals in the egg white and egg yolk to form various sulfides, so the color of the egg white and egg yolk changes, the egg white is a special brown color, and the egg yolk is dark green. The salt in the ingredients can shrink the preserved eggs and increase the flavor.

The tannins and aromatic oils in tea can color the coagulated proteins and add flavor to the preserved eggs. The function of lead oxide is to regulate and control the penetration rate of alkali into the egg in the feed, so as to prevent the formation of "alkali wounded eggs" due to excessive alkali infiltration [1]. However, in the process of making and placing it, the lead oxide will gradually penetrate into the egg and cause the egg to contain lead.

Lead harm to the human body Lead can be harmful to a variety of tissues and organs of the human body, if long-term consumption of food with too high lead content will cause chronic cumulative poisoning: mild cases will cause loss of appetite, weight loss, nausea and other symptoms. In severe cases, it can cause damage to the central nervous system and lead to encephalopathy, causing vasospasm, increased blood pressure, and increasing the incidence of cerebral hemorrhage; inhibits the anabolism of hemoglobin, leading to anemia; It can cause decline in kidney function and kidney disease; It has a toxic effect on the reproductive system, reducing male fertility and increasing the rate of miscarriage, preterm birth or stillbirth in women.

It is also easy to cause ADHD in children, resulting in poor attention, memory loss, reduced comprehension or learning difficulties, which can seriously affect the normal development of children's physique and intelligence; Lead also has carcinogenic effects, etc. Due to the addition of lead oxide in the traditional formula, the lead content in preserved eggs is too high, which affects the health of the human body. As a result, lead-free preserved eggs with zinc sulfate, selenium sulfite, etc., instead of lead oxide, came into being after the improved process, but the lead-free preserved eggs are not lead-free but have low lead content.

GB2749-1996 "Hygienic Standard for Egg Products" stipulates that the lead content of preserved eggs in traditional processes shall not exceed 2mg kg, and the lead content of preserved eggs in improved processes shall not exceed 2mg kg.

Preserved eggs are also known as Songhua eggs, because preserved eggs are pickled by mixing soda ash, lime, salt and lead oxide, wrapping duck eggs, which contain lead, according to national regulations, the lead content of Songhua eggs per 1000 grams shall not exceed 3 mg, so as long as the preserved eggs you buy are in line with the national standard, it is about 1-3mg kg.

According to the regulations of the Taiwan Department of Health, the lead content of preserved eggs shall not exceed 2ppm, and the copper content shall not exceed 8ppm, and the agricultural administration unit also counsels the industry to produce high-quality preserved eggs, so that the lead content shall not exceed the copper content shall not exceed 5ppm, so the impregnating solution of qualified manufacturers does not add heavy metals, or the content is very small. However, when many preserved eggs are pickled, if you do not master the ingredients of pickling, it is easy for preserved eggs to have a high lead content, so you should eat them, and you should also buy qualified and common preserved eggs, and you should eat less.

According to national regulations, the lead content of every 1000 grams of Songhua eggs shall not exceed 3 mg, so as long as the preserved eggs you buy meet the national standard, it is about 1-3mg kg.

Eating preserved eggs will not be poisoned.

The whole process of preserved eggs is more wonderful: a raw duck egg, wrapped in grass ash for thirty or forty days, and then opened to become a dark green, fully transparent, and can be taken at the same time, and the taste is still unfinished. Through technical improvements, preserved eggs are usually mixed with lime powder, tea, edible salt, face alkali, plant ash, loess layer, chaff, etc. as a slurry, and the fresh duck eggs without cracks are wrapped in mud one by one, and sealed tightly with plastic film for 30-40 days that is, preserved eggs.

On preserved eggs, there is also a common pattern like pine flowers, which is actually formed by the decomposition of proteins in preserved eggs under the effect of alkaline substances. Similarly, the color of preserved eggs is due to the strong acidic effect of the egg white, the egg white part will show reddish-brown or dark brown, and the egg yolk will show dark green.

Duck eggs change from fresh to preserved eggs, and the moisture content is reduced to a certain extent, and the transformation of egg white and body fat is not large. However, the sodium content in preserved eggs is much higher than that of duck eggs, which is also due to the fact that in the process of making preserved eggs, the edible salt and alkali added to the mash have sodium, which can penetrate into the preserved eggs according to the subtle gaps in the egg shell. High sodium content is a risk source for people with high blood pressure, and it is advisable to eat less.

For preserved eggs, Chinese have never felt disgusting and want to vomit, but what worries consumers is its safety factor. Bian Huawei said that in the traditional Chinese recipe for the production and processing of preserved eggs, lead oxide is added, because lead is a harmful heavy metal element, which seriously affects the nutritional content of preserved eggs, and even involves the safety factor of ingredients. Therefore, through a variety of scientific research, the production of heavy metal-free preserved eggs.

That is, to find a substitute component for lead oxide, in which EDTA and FWD scales are used well.

In addition, in addition to lead, preserved eggs usually contain heavy metals such as zinc and mercury, and children have a strong absorption of heavy metals, so parents are reminded to pay attention to it, or give children less preserved eggs. To take preserved eggs, you also need to buy preserved eggs produced by professional manufacturers.

Yes, because the lead content in preserved eggs is relatively high, eating too much will lead to lead poisoning, the nutritional value of preserved eggs has increased iron content, rich protein, contains a variety of minerals, increases appetite, easy to digest and absorb, and can also cite lead to relieve hangover and wake up the wine, clear the heat and get rid of the fire.

Eating too many preserved eggs can indeed lead to lead poisoning. Preserved eggs are rich in protein, fat, vitamins, calcium, phosphorus, potassium and other trace elements.

The lead oxide used in our traditional preserved eggs is lead oxide to provide metal ions, so lead ions also penetrate into the preserved eggs in the process of lead ions and the decomposition of the long-lived sulfur ions from the protein in the egg to form insoluble salt sulfide to block the eggshell pores.

In the production process of preserved eggs, it mainly involves the selection of raw eggs, soaking with material liquid, taking out and inspecting, coating mud film, packing and storage, among which sodium hydroxide (NaOH) and metal ions must be used in the process of soaking in raw eggs. NaOH is added to the soaking solution to make the liquid alkaline and promote the coagulation and alkalinization of egg whites and yolks; The main purpose of adding metal compounds is to combine them with the sulfur ions produced by the decomposition of proteins in the egg, generate insoluble salt sulfides and block the pores of the eggshell, hinder the continuous penetration of OH- into the egg, and cause "alkali injury" in the later preserved eggs, resulting in the reprogramming of the coagulated protein in the liquid state.

Many studies have confirmed that lead has a huge toxic effect on the human body, mainly damaging the nervous system, affecting children's memory, language and motor skills and learning ability. As a result, more and more lead-free processes are being used to make preserved eggs. The lead-free process means that no lead compounds are used to provide metal ions during the processing of preserved eggs, but zinc, iron, copper ions, or a combination of these ions are used to provide metal ions.

However, it should be noted that lead-free preserved eggs do not mean that preserved eggs are completely lead-free, because in the natural world we live in, air, soil, and water will contain trace amounts of lead, which will exist in the indispensable raw materials for us to make preserved eggs - fresh eggs, so it is almost impossible to make preserved eggs absolutely lead-free.