Summer heat rises, and some people may experience loss of appetite. The refreshing and appetizing diving kimchi has become a must-have for many people when ordering takeout. Due to the short soaking time, many consumers may feel that compared to other pickled kimchi that has been marinated for a long time, diving kimchi has a relatively higher safety factor. Does this mean that in summer, one can open up and eat diving kimchi every day? Diving kimchi is not suitable for daily consumption. Diving kimchi is also known as "bath kimchi". The production process is like jumping into pre prepared salt water to take a bath, soaking it the day before, and it can be consumed the next day. Wu Xiaomeng, associate professor of the School of Food Science and Nutrition Engineering of China Agricultural University, told the China Consumer Daily that from the perspective of food safety, diving pickles would produce relatively little nitrite due to the very short pickling time. In addition, such pickles that are pickled for a short time will sometimes be added with a moderate amount of Baijiu and stored at low temperature, which is not conducive to the reproduction of miscellaneous bacteria and the production of nitrite. Therefore, while ensuring the hygiene of pickling, the safety factor of diving kimchi is relatively high. Wu Xiaomeng explained that vegetables contain nitrate, which is converted into nitrite under the action of reductase and bacteria. The nitrite content in kimchi fluctuates over time. Research shows that the nitrite content generally reaches its peak within 5 to 10 days after pickling kimchi. After soaking kimchi for 20 days, the nitrite content gradually decreases and reaches the limit value lower than the national standard. So, in terms of time, diving kimchi that avoids the peak of nitrite and old kimchi that has been pickled for more than 20 days can be consumed in moderation. Diving kimchi is only relatively safe, so it is generally not recommended to eat it every day and open it up. Meanwhile, it is best to finish the diving kimchi purchased at home within 2 to 3 days, otherwise the remaining nitrate content in the diving kimchi will gradually increase over time. Wu Xiaomeng's analysis suggests that from the perspective of salt content, diving kimchi may not necessarily be lower than traditional kimchi. Because this type of kimchi is easy to pickle and adds flavor, a large amount of salt is used to remove excess water from the vegetables, and sugar is added to ferment lactic acid bacteria, increasing the sour taste of kimchi. It's okay to occasionally try this type of kimchi as a fresh side dish, but if you eat it frequently and in large quantities at once, it may increase your intake of salt and sugar, thereby affecting the stability of blood pressure and blood sugar. Probiotic supplementation does not need to rely on kimchi. Kimchi is a fermented food, and experiments have shown that kimchi can supplement intestinal probiotics. Therefore, some people say it is a "intestinal health product" and can be eaten more. Is this statement reliable? Wu Xiaomeng analyzed that many vegetables naturally have lactic acid bacteria and other bacteria attached to their surfaces. In the ideal pickling process of kimchi, high salt and anaerobic environments lead to the death of many salt intolerant and oxygen requiring microorganisms. Lactic acid bacteria can continuously reproduce using the nutrients in vegetables, becoming dominant strains, thus giving kimchi storage resistant characteristics and unique flavors. The fermentation process of kimchi dominated by lactic acid bacteria produces a large amount of delicious substances. The study found that whether Sichuan pickles, Jiangxi salt dishes or northeast pickled Chinese cabbage, these fermented vegetables are rich in amino acids such as glutamic acid and alanine. The presence of these delicious substances is the foundation of the deliciousness of kimchi. From a nutritional perspective, eating kimchi can indeed supplement probiotics, dietary fiber, as well as minerals such as potassium, iron, and manganese. However, none of these can be a reason to eat more kimchi. Wu Xiaomeng explained that in addition to relatively high salt content, a long-term high salt diet may damage the protective layer of the gastric mucosa and other adverse factors, pickled vegetables such as kimchi may also lose vitamin C, vitamin B, and some antioxidant plant compounds compared to fresh vegetables. completely replacing fresh vegetables with kimchi may lead to a lack of these nutrients. In addition, studies have shown that eating too much pickled vegetables increases the risk of developing stomach cancer. From the perspective of supplementing intestinal probiotics with fermented foods, choosing to eat kimchi is obviously not as safe and appropriate as consuming other fermented foods such as yogurt and cheese. Especially for people with normal gut microbiota, there is generally no need to supplement too many probiotics. Just pay attention to a balanced diet, eat fresh vegetables and coarse grains rich in dietary fiber, and the gut can regulate itself to maintain the balance of gut microbiota, without blindly eating pickled vegetables. It is not recommended to find a balance between delicious and healthy homemade kimchi, and to eat kimchi with peace of mind and peace of mind. Wu Xiaomeng reminds consumers to refer to the following methods: Firstly, purchasing branded kimchi from large-scale supermarkets is relatively safer. After purchase, pay attention to avoiding light and storing at low temperature. After opening, be careful not to expose it directly to the air. If you cannot finish it, it needs to be sealed and refrigerated to minimize the risk of microbial contamination. Secondly, kimchi placed open in markets and restaurants is generally not recommended for consumption. One is the high risk of direct exposure to air pollution, and the other is the inability to determine how long the kimchi has been soaked. Especially for some small vendors who sell loose kimchi, due to issues such as pickling time and purity of fermentation bacteria, the nitrite content is high, and there is even a risk of food poisoning after consumption. Thirdly, kimchi can be cooked together with other ingredients. By pairing more fresh vegetables, supplement the vitamins lacking in kimchi. It should be noted that it is generally not recommended to make homemade kimchi at home. Many households can easily mix some miscellaneous bacteria when pickling kimchi due to improper operation, which can increase the production of nitrite and also bring the risk of microbial contamination. If a family still wants to try homemade kimchi, Wu Xiaomeng reminds them to pay extra attention to the following points: try to use fresh vegetables for homemade kimchi, clean it before pickling, and blanch it in water if it does not affect the taste; It is recommended to directly purchase pure lactic acid bacteria powder for fermentation, using clean drinking water, or using previously marinated aged kimchi water. These can effectively avoid impurities and reduce the possibility of producing nitrite. Keep the knives, containers, and production environment clean and hygienic, and wash hands before each contact with kimchi. Both during pickling and after opening, it is important to ensure proper sealing. At the same time, try to reduce the number of times the container is opened, avoid the entry of miscellaneous bacteria, and increase the content of nitrite. Extend the fermentation time, unless it is a diving kimchi that is soaked overnight, try to marinate it for 20 days to 1 month before starting to eat. If the smell or taste is not right after opening, it should be discarded immediately. (Lai Xin She)