Source: Science Popularization China
Experts in this article:
Zhao Aili, Fujian Medical University, doctoral degree in nutrition and food major
Wang Wenxiang, a professor at Fujian Medical University, doctoral tutor for nutrition and food majors
Preserved eggs, also known as pine eggs and changing eggs, are traditional Chinese food.
Many people like to eat preserved egg lean porridge, egg tofu, preserved egg rolls …
But in recent years, there have been rumors that "preserved eggs contain high lead, which will be chronic poisoning, or even carcinogenic!"
This makes many people who love preserved eggs are discouraged, so can preserved eggs be eaten?Who can’t eat?
What is the pattern on the preserved egg?Is it harmful to the human body?
For the origin of the pattern on the preserved egg, some netizens think that this is caused by the uncertainty of the preserved eggs, and eating is harmful to the human body.
the truth:
The pine egg is named after its surface with a variety of pine patterns. The pine flower is actually a crystal formed by the degradation product of the egg white protein under alkaline conditions with the combination of magnesium ions in the protein.
Therefore, this crystallization that has been formed for a long time is not caused by unclean, nor will it harm to human health.
Preserved eggs are high in lead and will chronic poisoning and carcinogenic?
actually not.
In traditional crafts, preserved eggs use duck eggs as raw materials, and then add lime, plant ash, salt, tea, and edible alkali to decompose and condense through long protein, and do not contain lead.
However, through the transformation of modern technology, some people who make preserved eggs will supplemented by "Huang Dan powder" to speed up the maturity of preserved eggs, so that preserved eggs form beautiful pine flowers to prevent further liquefaction of protein.
Among them, the main component of Huangdan powder is lead oxide. During the production of preserved eggs, part of the lead oxide will penetrate into the eggs, and leading lead may occur.
However, as early as 2015, my country improved the production process of "lead" preserved eggs and will not add lead -containing substances to preserved egg production. Therefore, there are lead -free preserved eggs on the market, and there are no problems with heavy metals.
However, "lead -free" preserved eggs do not mean that it does not contain lead. According to relevant national regulations, the preserved egg containing the leading amount does not exceed 0.5 mg/kg, which can be marked as "lead" and will not damage human health.
So why are there any cases of poisoning for poisoning because of eating preserved eggs?
The "culprit" is actually bacterial food poisoning, especially Salmonella’s food poisoning.
Salmonella is widely existed in nature, but it is not heat -resistant and can be killed at high temperature.
The Salmonella in the livestock and poultry intestines pollutes eggs through excretion. The precipitated temperature of preserved eggs is not enough to kill Salmonella. The acid -base environment can survive, and because the preserved egg processing temperature is not high enough (cold), it cannot play a role in high temperature sterilization. ThereforeThere are often cases of food poisoning for preserved eggs contaminated by Salmonella.
Therefore, before eating preserved eggs, it is necessary to cook at high temperature to kill Salmonella.
What are the benefits of eating preserved eggs?
1. Provide rich protein, fat, carbohydrates and minerals
Preserved eggs are made of duck eggs. They are rich in protein like fresh duck eggs. After pickling, protein decomposition is more conducive to the digestion of the human body. The protein and fat content is not inferior to fresh duck eggs.
In addition, preserved eggs can also provide rich minerals such as iron, zinc, selenium, etc.
2. Increase appetite
Preserved eggs have a unique flavor (ammonia, hydrogen sulfide), which can stimulate digestive organs, regulate appetite, and easy to digest and absorb.
Data source: "Chinese Food ingredients Table" (2009 edition)
In short, preserved eggs are rich in protein and are easy to absorb. They are also rich in minerals such as iron and zinc, which can also enhance appetite. It is an egg product with unique flavor and high nutritional value.
Which people should not eat preserved eggs?
1. People with poor constitution
Preserved eggs are easily contaminated by Salmonella. After entering the inside through egg holes, they may cause discomfort after eating poor people. Even food poisoning, diarrhea, vomiting, and fever, such as the elderly, children, pregnant women, and chronic diseases.
2. Children and pregnant women
Although "lead -free preserved eggs" are sold in the market, they still contain trace lead. People with sensitive leaders such as children and pregnant women should eat less or not, because excessive intake may damage children’s children’s which can damage children’s children’s.Nervous system development, kidney function, and fetal development.
3. Patients with hypertension
The sodium content in preserved eggs is more than 5 times that of ordinary duck eggs. Excessive sodium intake has been clearly clear that it is one of the important risk factors of hypertension. Therefore, patients with hypertension should not eat more.
How to choose preserved eggs?
1.
Get the preserved eggs in your hand and sip, good preserved eggs will have weight and feel.
2. Shake
Pick up the preserved eggs and shake it. The good preserved eggs are elastic, and some bad preserved eggs will feel broken.
3. Hear a smell
Good preserved eggs will have a nasal alkali flavor. If the preserved eggs are rotten and deteriorate, there will be a pungent odor.
Some people think that the less dark spots, the less heavy metal content. In fact, the amount of dark spots is related to the marinating time and production temperature, and has nothing to do with heavy metal content.
It is recommended that you buy it in a regular supermarket to avoid possible security risks.
