On the fourth day after pickling, the ammonium nitrite in the pickle jar reached its peak. On the tenth day, the nitrite content in kimchi began to decrease obviously. After 20 days, the content of nitrite decreased obviously, and it was safe after one month.
Pickled vegetables can use a variety of raw materials, such as white radish, carrot, cucumber, lettuce, garlic moss, lotus root, pepper and so on. Chinese traditional pickle products include potherb mustard in Shanghai, pickled mustard tuber in Fuling, Chongqing, sour bamboo shoots in Guangdong, kohlrabi in Yunnan and dried sweet radish in Changzhou. In foreign countries, Japanese pickles and Korean pickles have long enjoyed a good reputation.