Text | Science Wormhole A Chinese delicacy that is both delicious and delicious cannot be separated from the skill of the chef and a good pot. Iron pot is one of the favorite cooking utensils among Chinese people. People think that the dishes fried in iron pot are more fragrant a

Text | Science Wormhole

A Chinese delicacy that is both delicious and delicious cannot be separated from the skill of the chef and a good pot. Iron pot is one of the favorite cooking utensils among Chinese people. People think that the dishes fried in iron pot are more fragrant and delicious, and it can also help to supplement iron.

As a tool that people use every day, the quality of iron pot is also related to our health. It is understood that CCTV has exposed " poisonous iron pots " many times. Using these pots for cooking will fry harmful "poisons" . Let's learn about it together.

"Poisonous Iron Wok" turns delicious food into "poison" and has been repeatedly exposed by CCTV

In 2011, CCTV exposed problematic woks. Discarded iron barrels that had stored chemical products, oils, and paints were polished and processed into iron pots for cooking.

The reporter randomly purchased such an iron pot and sent it to Wuhan Mineral Resources Testing Center for testing. The results showed that metal elements harmful to the human body such as chromium, cadmium, lead, arsenic, and antimony were detected in the iron pot samples.

Testers said that based on other industry standards, the content of toxic and harmful elements in the iron pot samples has seriously exceeded the standard, and the chromium content exceeded the standard by more than 200 times.

In this regard, the person in charge of the Wuhan Municipal Quality and Technical Supervision Bureau told reporters that the domestic cast iron pot industry only has appearance, size and other indicators, and there is no clear national mandatory standard for raw materials.

A CCTV report in 2013 once again exposed the incident of abandoned chemical barrels transformed into woks. In Shangrao, Jiangxi, a reporter discovered through an undercover investigation that a factory uses chemical waste iron barrels to cast iron pots.

On the way to the factory, the reporter passed the 20 National Highway . We could see used chemical iron barrels piled randomly beside the road, and the air was filled with a pungent smell .

In the factory, there is a shiny iron pot. Workers told reporters that making such an iron pot requires a lot of processes, including cutting the iron barrel, pressing rectangular iron sheets, cutting into iron sheets, burning them with fire, soaking them with sulfuric acid, etc.

The purpose of these processes is to turn the iron sheets into a uniform gray-black color and to remove the pungent smell and "dirty things". The cleaned iron pieces should also be soaked in hydrochloric acid and lime water.

Finally, after polishing and oiling these iron pots and installing handles, the iron pots without quality inspection marks were completed. It is understood that one iron bucket can make several iron pots, and one village can produce 490,000 iron pots a year.

The market price of an iron pot made of discarded chemical barrels is only a dozen yuan. It is usually purchased by people who lack food safety awareness (mostly the elderly) or in restaurants. Although the price is cheap, the processing factory's income is not large because the raw materials are cheaper.

Are there any dangers in using these iron pots for cooking?

On the chemical barrels used in these factories, we can see the words , " isopropyl alcohol ", " trimethylchlorosilane " , etc. These are chemical ingredients; some chemical barrels also have skulls. pattern, which is a sign of toxic chemicals .

Workers at the iron pot processing factory said that they process iron drums in multiple processes to remove chemical residues, but sometimes the results are not very satisfactory. It can also be seen from the test results in Wuhan that these "poisonous iron pots" have the problem of excessive heavy metals.

As the saying goes, " disease enters from the mouth, and disaster comes from the mouth." Common people use pots for three meals a day. If used for a long time, excessive heavy metals in the iron pot will accumulate in the human body, leading to poisoning.

Take lead as an example, which is a chemical that is extremely harmful to the human body. Excessive accumulation of lead in the body will damage various systems throughout the body. If the victim is a child, the child may suffer from developmental delays, mental retardation, etc.

How to choose a qualified iron pot?

"Poisonous iron pots" threaten the health of our people, so everyone must be vigilant and keep their eyes open when buying iron pots.

First of all, when you see an iron pan that is too cheap, be more cautious. There are indeed many "high-quality and low-priced" products in the world, but the raw material cost and labor cost of a qualified iron pot are relatively high, so its selling price cannot be only more than ten or twenty yuan. .

Secondly, when purchasing iron pots, you should choose products with quality certificate, manufacturer, production address and other information. Do not buy products with three no products.

Smart friends will directly choose iron pots from big brands, but they should also identify them carefully when buying, and try to buy from official channels to avoid falling into the trap of "copycat brands".

Can cooking in an iron pot really replenish iron?

The lack of trace elements in the human body will cause various discomforts and even cause iron deficiency anemia and other diseases. Chinese people believe that cooking in an iron pot can replenish iron, which is an economical and practical way to replenish iron. The question is, can cooking in a wok really replenish iron?

The answer is: yes, but the effect is extremely limited. First of all, let’s take a look. Stir-frying in iron pots can provide three forms of iron to the human body. They are: elemental iron, ferrous ions ( divalent iron ions ), iron ions (trivalent iron ions). iron ions) .

The elemental iron provided by the iron pot for cooking mainly comes from the "iron filings" that enter the dish due to the friction between the iron pot and the spatula. After being eaten by the human body, it reacts with the hydrochloric acid in the gastric juice to produce "ferrous ions", which are then absorbed.

Ferrous ions (divalent iron) are mainly produced when plant juices, vinegar and other acidic substances react with iron pots when cooking, and are absorbed by the human intestine after consumption.

Iron ions (ferric iron) are mainly derived from rust on iron pots. After entering the human body, they are reduced to ferrous ions under the action of enzymes in the intestines.

Perhaps you have discovered that in order for the three forms of iron in iron pots to be absorbed by the human body, they all need to be converted into ferrous ions. Why is this? Experts point out that what can be absorbed by the human body is ferrous ions (divalent iron) .

Moreover, ferrous ions are inorganic ions, and the human body's absorption and utilization of them is very low. Therefore, the iron supplement effect of iron pot cooking is very limited.

The authoritative medical journal "The Lancet" mentioned: In developing countries, if there are no additional drugs or vitamins to supplement iron, cooking in an iron pot may be an effective way to prevent iron deficiency anemia.

At first glance, many friends will think that iron pot supplementation is quite reliable, but we should note that the word "may" is used in the article, not "can".

Bai Bing, a lecturer from School of Food of Shenyang Normal University, pointed out that the iron that is beneficial to human body absorption is mainly heme type iron, which is present in animal foods .

During the period of material scarcity in our country, iron pots were helpful in replenishing iron; but now that people’s living standards have improved, eating meat and animal livers will have a better effect than iron pots.

Generally speaking, iron pot cooking does have the effect of supplementing iron, but this effect is very not obvious. If you have iron deficiency anemia, you should not place all your hopes on the iron pot.

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