Shocking! If you don’t blanch these four types of vegetables, the consequences will be so serious!

Have you heard of the term "blanching"? Most friends who can cook Chinese food know that it means boiling a pot of boiling water, then putting the washed vegetables or processed meat in and boiling for a while. The meat must be skimmed off the foam, and then the vegetables and meat are taken out and drained for processing. The whole blanching process is basically completed. Unlike blanching meat to remove blood and fishy smell, the following four types of vegetables must also be blanched before cooking.

Category 1: Vegetables with high oxalic acid

Such as spinach, amaranth, fresh bamboo shoots, bitter gourd, etc. Oxalic acid easily combines with calcium in human food to form insoluble calcium oxalate. Calcium oxalate is not only unable to be absorbed and utilized by the human body, but also affects the body's absorption of calcium. Oxalic acid is also a taboo for patients with urinary tract stones. After consuming spinach, the amount of oxalic acid excreted in the urine increases significantly, increasing the risk of stone formation and possibly aggravating the condition [1].

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The second category: vegetables with high nitrite content

For example, Chinese toon contains high levels of nitrite. In an acidic environment such as nature or the gastrointestinal tract, nitrite can be converted into nitrosamines, which are highly carcinogenic. At the same time, excessive consumption or improper handling can easily lead to nitrite poisoning, which can cause damage to the liver cell structure and function, and in severe cases, acute liver failure [2]. The nitrite content of freshly picked vegetables is very low, but after being left at room temperature for 3 days or in the refrigerator for 5 days, the nitrite content will reach the highest level. It is recommended to buy vegetables and eat them immediately.

Category 3: Eating Toxic Vegetables Raw

Such as beans, fresh day lily, and legumes. Beans contain two toxic substances, betaine and saponin. If they are not blanched in advance and not fully cooked during cooking, these substances will irritate the human stomach and intestines, easily causing symptoms of food poisoning such as nausea, vomiting, and numbness of the limbs. Children are particularly vulnerable to food poisoning if they eat undercooked beans, especially since their stomachs are not fully developed.[3]

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The fourth category: vegetables that are difficult to clean

Such as black fungus, broccoli, etc. If vegetables are not cleaned properly, pesticides and microorganisms are likely to remain. Long-term consumption of fruits and vegetables contaminated with pesticides will cause some chronic diseases such as cancer, arteriosclerosis, cardiovascular disease, fetal malformation, stillbirth, premature death, premature aging, etc. Ingestion of bacteria may cause gastrointestinal discomfort and food poisoning. Parasites (eggs) will also adhere to food and enter the human body through the digestive tract, causing parasitic infection.

Blanching the above four types of vegetables in boiling water before cooking can greatly reduce the harmful substances in them and make them healthier!

References:

[1] Wu Shang. Determination of oxalic acid content in spinach and its impact on health[J]. Research on Mathematical and Physics Problem Solving, 2018, (22): 95-96.

[2] Li Ping, Han Mei, Han Tanqian. Clinical treatment and nursing of a case of acute liver failure caused by nitrite poisoning due to excessive consumption of toona sinensis[J]. Qilu Nursing Journal, 2023, 29(09): 159-161.

[3] Zhang Wei, Bai Jinping, Mao Xuemei, et al. Two cases of physostigmine poisoning caused by eating beans and literature review[J]. Gansu Science and Technology, 2020, 36(05):111-112.

Source: Chongqing Science Writers Association

Written by: Liu Xinyu, laboratory technician, Chongqing Yongchuan District Jimai Hospital (District Children's Hospital), Qiao Jie, chief technician, and Zou Jingbo, chief technician, from Zou Teacher Science Garden

Audit expert: Li Hanbin

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