What are the "black spots" on Chinese cabbage? Can you eat it?

In the cold winter, doesn’t it feel comfortable to drink a bowl of steaming cabbage soup?

Cabbage is a common guest on the table and can be paired with many ingredients to make hearty dishes.

Eat happily, but also eat wisely. How much do you know about cabbage?

Where did the saying "no vegetable is worse than cabbage" come from? What is the nutritional value of cabbage? Can you still eat cabbage with black spots? Can eating cabbage for 21 consecutive days "detoxify" you?

Next, I will answer all of your questions.

“No vegetable is worse than cabbage”?

According to the "Chinese Vegetable Cultivation" (Second Edition), cabbage vegetables can be divided into Chinese cabbage, common cabbage, black cabbage, Chinese cabbage, cabbage and purple cabbage. In life, the cabbage people refer to is generally Chinese cabbage or yellow cabbage (scientific name cabbage), and small cabbage or green cabbage (scientific name non-heading cabbage).

Cabbage comes in many varieties, has a fresh texture, and is rich in nutrition. It contains more trace nutrients and some phytochemicals (such as flavonoids, carotenoids, etc.).

Cabbage can be paired with many ingredients to make a variety of dishes, such as stir-fried cabbage, cabbage stewed with tofu, spicy cabbage, etc. It can also be made into pickled vegetables (such as sauerkraut) and stored as an appetizer on the table.

Chinese cabbage is relatively durable in storage. In the era when planting technology was not developed and transportation was not convenient, it was difficult to grow vegetables in the north of my country in winter. Chinese cabbage might be the only vegetable that could be put on the table in winter. Moreover, compared with other vegetables, the price of Chinese cabbage is relatively low and the fluctuation range is small. Therefore, there is a saying among the people that "no vegetable is worse than Chinese cabbage".

Cabbage is rich in dietary fiber. Related studies have shown that dietary fiber is related to the prevention or treatment of some chronic non-communicable diseases, such as gastrointestinal diseases, diabetes, cardiovascular diseases, etc. In addition, my country's dietary guidelines recommend that we eat vegetables at every meal and ensure that we eat 300g to 500g of vegetables every day.

Can we still eat cabbage if it has "black spots"?
When people buy Chinese cabbage, they will find that some cabbages have some black or dark-brown spots similar to sesame seeds on the veins and petioles. This is a physiological disease of Chinese cabbage called "sesame spot disease."

This physiological disease is mainly caused by the combined effects of the cabbage variety's intrinsic genetics, external cultivation measures (such as excessive fertilization) and environmental conditions. Moreover, this disease also occurs in other cruciferous leafy vegetables such as rapeseed and cabbage.

However, this physiological disease mainly affects the commercial value of Chinese cabbage, such as the decline in appearance quality affects the purchase rate and export, etc. It basically does not harm our health and can be eaten normally. It should be noted that if the black spots are large pieces caused by corruption and deterioration, they should be avoided.

It should be noted that excessive nitrogen fertilizer application may cause excessive nitrate content in vegetables, and nitrate will be converted into nitrite (NO2⁻) by microorganisms in the human body, and large amounts may be harmful to human health. Therefore, when growing Chinese cabbage, people should not use excessive nitrogen fertilizer, which will not only help reduce the occurrence of sesame spot disease, but also ensure food safety.

Can eating cabbage for 21 consecutive days help detoxify?

Usually, the term "detoxification" refers to the process of excreting harmful substances from our body, but this is just a "marketing" concept that is easier to understand, not a scientific concept. Our body is exchanging substances with the outside world every day, and the metabolites (the so-called "toxins") produced by metabolism every day are excreted from the body through the end of the digestive system and the urinary system. This is a natural process.

"Toxins" will not be excreted just because you eat certain foods, but the ingredients of certain foods are beneficial to the work of some organs in our body, such as dietary fiber, which promotes intestinal peristalsis. Therefore, eating cabbage for 21 consecutive days is not necessarily related to the so-called "detoxification".

In addition, some beneficial ingredients are found in many foods, so there is no need to be obsessed with a single food, otherwise it will easily cause nutritional imbalance, which in the long run can easily induce some diseases, such as metabolic disorder syndrome.

How to store cabbage correctly in winter?

The main component of Chinese cabbage is water. If you want to preserve it for a long time while maintaining its fresh and tender texture, you must first keep it away from light and at a low temperature. By affecting the activity of enzymes related to plant cell respiration, you can inhibit the respiration of plant cells and thus reduce the metabolism of Chinese cabbage.

In addition, if conditions permit, the shelf life of the cabbage can be extended by isolating oxygen, reducing the respiration of cabbage cells and reducing the consumption of organic matter.

Expert of this article: Zhang Zhaomin, Master of Food Science, Senior Engineer