If ferrous sulfate is used, it can produce black color, and together with other odorous substances, it can become stinky tofu. This is quite dangerous, too much iron is very harmful to the human liver, and its odor may be caused by corruption in protein, so it is possible to say that it is carcinogenic.

The reason why stinky tofu stinks is undeniable that its odor will have protein's corrupt substances-amines, which can react with nitrite to generate nitrosamines. I believe everyone knows that nitrosamines are strong carcinogens;

It is suggested that when eating stinky tofu, it is best to eat more fresh vegetables and fruits, because fresh vegetables and fruits are rich in vitamins, especially vitamin C, which can block the generation of nitrosamines.

2. Poisonous bacteria destroy the nervous system

During the fermentation process of stinky tofu, a large amount of basic nitrogen will be volatilized. There is a kind of poisonous bacteria called Clostridium botulinum, which often multiplies with the production of stinky tofu. Botox is a deadly bacteria that secretes toxins during the reproduction process and is one of the most toxic protein.

After people ingest and absorb this toxin, the nervous system will be destroyed, and symptoms such as dizziness, dyspnea and muscle weakness will appear.

3, cause human gastrointestinal diseases.

The fermentation process of stinky tofu is carried out under natural conditions and is easily contaminated by microorganisms. In addition, Mucor was used in the early stage of stinky tofu fermentation, and it was easily contaminated by other bacteria, including pathogenic bacteria, in the late stage of fermentation. Therefore, don't eat too much stinky tofu at a time, so as not to cause gastrointestinal diseases.

Stinky tofu itself is moldy food. Try not to eat it if the stomach is bad, otherwise it will easily cause stomach pain and bloating, abdominal pain and diarrhea.

4, unsanitary affect health.

At present, most stinky tofu is made from chemical dyes, rotten water, sewage and even manure. Unscrupulous workers first cut tofu into pieces and boiled it in water, and added black powder. After a few minutes, the tofu was all dyed purple-black.

After drying in the sun, it is soaked in a dark and smelly bucket and stinks. Black water is made of snails, rotten water, carrion and dead flies, which are fermented and sealed to maggots, producing a pungent smell. If it's not smelly enough, add a little manure to make it smelly.

Extended data:

Stinky tofu, a traditional specialty snack in China, is quite different in the way of making and eating in different places, and there are different types in the north and the south. Stinky tofu is also called Stinky Son in the south. Although its name is tacky, but it is ugly outside and beautiful inside, and it has a long history. It is a very distinctive traditional Chinese snack, ancient and traditional, which makes people want to stop. The production materials are soybean, fermented soybean, soda ash and so on.

There are regional differences in the way of making and eating in China and around the world, and their tastes are also very different, but they have the characteristics of "stinking and delicious". Changsha stinky tofu is quite famous, and so are Nanjing, Taiwan Province, Zhejiang, Shanghai, Beijing, Wuhan and Yulin.

Most of the streets in Tianjin are stinky tofu in Nanjing, which is fried into golden yellow for gray tofu blocks, and the smell is very weak. The stinky tofu on the streets in the south is mostly "Changsha stinky tofu", but it is made in a different way. It is fried with iron plate, which is not empty and light yellow.

People's Daily Online-Eating stinky tofu is harmful. 3 tricks to teach you to distinguish inferior products.

Baidu encyclopedia-stinky tofu (snacks)