Nitrate and nitroso compounds will be produced in the pickling process of pickled Chinese sauerkraut. Both of them are extremely strong carcinogens, especially the latter. For example, if you eat 0.3 grams of nitrite by mistake (because the physical properties are the same as salt, it is easy to eat it by mistake), you will die. Very toxic.

Then you have to ask, why do people eat sauerkraut every day and why are they not poisoned? That's because the content of harmful components in pickled cabbage will reach the peak after 3 to 12 days, but it will drop greatly after a long time, so it's best to eat pickled cabbage pickled for more than 20 days, which is very safe, and the intake of harmful substances is very small, which will be excreted with the body's metabolism and will not cause harm, but it is still necessary to take it in moderation. After all, pickled sauerkraut is not a good thing. Also, fresh vegetables will produce nitroso compounds if they are kept for a long time. It's best not to eat, especially children, who are very sensitive.