Whether kimchi or pickles, 1~3 days after pickling is the period of the highest content of carcinogen nitrite, and its content shows an increasing trend in this time period. Generally speaking, from the 3rd day onwards, the oxygen in the kimchi altar is exhausted because of the continuous reproduction of microorganisms, and the nitrate content in vegetables is gradually reduced due to oxidation, and the content will gradually decline and tend to a relatively stable value.

This takes close to 15 days. 20 days later, the nitrite content will drop to a very low level and become nitrate. Therefore, kimchi should be consumed after 20 days of pickling, and it is relatively healthy to consume long term (more than 30 days) stored. It should be noted that the pickle lid should not be opened in pickling, because the entry of oxygen is not conducive to the reduction of nitrite content.

The human body ingests too much nitrite, nitrite into the blood, can be combined with hemoglobin to form methemoglobin and the loss of oxygen-carrying function, the seriousness can be asphyxiated. The danger of nitrite is not only this, nitrite in the body may also be converted to nitrosamines, this is because nitrite can be with animal and high protein food widely available amine substances to react.

The generation of carcinogenic nitrosamines. Therefore, nitrite threatens human health as a precursor substance for the synthesis of nitrosamines.

Extended information:

Variation of Nitrites in Kimchi:

All plants contain nitrates and nitrites, and kimchi is made from fresh vegetables, which naturally contain nitrates and nitrites. The process of making kimchi is greatly influenced by fermenting bacteria. Research on kimchi has found that if pure acetic acid bacteria or pure lactic acid bacteria are used in fermentation, it does not lead to the production of many nitrites, because these bacterial activities almost do not produce nitrites.

However, in daily life when people make their own kimchi sauerkraut, there is no pure strain of fermentation conditions, inevitably contaminated with stray bacteria, there is indeed the production of nitrite trouble. But as long as the kimchi fermentation time is long enough, the nitrite content will not be very high, normal consumption does not have to worry.

Research has found that with the prolongation of the soaking time, the nitrite content will be gradually reduced, and finally even basically disappeared.

With or without nitrites, all kimchi has a lot of salt and is high in salt, so it's not good for your health to eat more of it. Instead, you can use it as an occasional substitute for salt in cooking.

While low in vitamin C, pickles are rich in potassium and dietary fiber, and you'll need to put salt in your cooking anyway, so why not use pickles as a substitute for salt? As long as you control the saltiness, not only can you add some minerals and dietary fiber over straight salt, but pickles also make the dish more flavorful and delicious.

People's Daily Online - The longer the kimchi is fermented ? The lower the nitrite content

Phoenix.com - How scary is the nitrite in kimchi? Don't underestimate its harm

People's Daily Online - Kimchi pickled enough for 20 days before eating