Stinky tofu smells bad but tastes delicious. Some people stay far away from it, while others have developed a hobby of eating it. In fact, stinky tofu is a fermented soy product. During its production, not only are certain spoilage substances produced, but it is also susceptible to bacterial contamination. From a health perspective, it is better to eat it in moderation. Research has shown that during the fermentation of soy products, substances such as methylamine, putrescine, and tryptamine, as well as hydrogen sulfide, are produced. These have a special pungent odor and high volatility, and eating too much of them is not beneficial to health. Furthermore, when amines are stored for a long time, they can react with nitrites to form strong carcinogens called nitrosamines.
Although stinky tofu is small, its production process is quite complex and must go through several procedures, including frying, brining, and fermentation. Throughout the entire production process, it must be carried out under natural conditions, and the requirements for temperature and humidity are very high. If not controlled properly, it can easily be contaminated by other bacteria. In mild cases, it can cause gastrointestinal diseases in humans, and in severe cases, it can lead to the massive growth of Clostridium botulinum, producing a toxic substance—botulinum toxin. This is a neurotoxin with extremely strong toxicity. Recent reported cases of stinky tofu poisoning have been caused by this toxin.[China Cuisine]
Because the production process of stinky tofu is complex, according to media reports, some people have come up with "simpler" methods to make it using chemical means. For example, using ferrous sulfate to dye the tofu black, and then adding other smelly substances, it can become stinky tofu. In China's "Food Hygiene Law," it is strictly prohibited to use the chemical raw material ferrous sulfate as a food coloring agent. In fact, stinky tofu is not without its merits. During its production, it can synthesize a large amount of vitamin B12. A deficiency of vitamin B12 in the human body can accelerate brain aging and easily lead to senile dementia. However, vitamin B12 exists in many animal foods such as meat, eggs, dairy, fish, and shrimp. Compared to these benefits, the disadvantages of stinky tofu should attract more attention.
If you really can't give up stinky tofu, it is recommended that you eat more fresh vegetables and fruits when you do so. The vitamin C they contain can block the formation of nitrosamines.