Some vegetables naturally contain toxins that cannot be removed unless they are heated and cooked. Consuming them raw can lead to illness. The editor has collected several types of vegetables that must be cooked before eating. Let's take a look.
Green Beans
Harmful Substance: Saponin
Cause of Illness: If green beans are not thoroughly cooked, the saponin in them can severely irritate the digestive tract. Additionally, beans contain a coagulant that has a blood-clotting effect. Furthermore, green beans also contain nitrites and trypsin, which can irritate the human stomach and intestines, causing food poisoning and symptoms of gastroenteritis.
Detoxification Method: To prevent green bean poisoning, be sure to cook them thoroughly.
Wood Ear Mushroom
Harmful Substance: Porphyria photosensitive substances
Cause of Illness: Fresh wood ear mushrooms contain porphyria photosensitive substances. Eating them raw can cause solar dermatitis, and in severe cases, lead to skin itching, swelling, and pain.
Detoxification Method: Do not eat fresh wood ear mushrooms. If you must eat them, be sure to cook them thoroughly.
Cassava
Harmful Substance: Linamarin
Cause of Illness: Although cassava roots are rich in starch, all parts of the plant, including the roots, stems, and leaves, contain toxic substances, with the fresh roots being particularly toxic. Therefore, caution must be taken when consuming cassava roots. The toxic substance in cassava is linamarin. Ingesting raw or undercooked cassava or its broth can cause poisoning. This is because linamarin or linamarase is hydrolyzed by stomach acid to produce free hydrogen cyanide, which poisons the body. A person can be poisoned by eating 150-300 grams of raw cassava, which can even be fatal.
Detoxification Method: To prevent cassava poisoning, peel the cassava and soak the flesh in water to dissolve the cyanogenic glycosides. Soaking for about 6 days can remove about 70% of the cyanogenic glycosides. After that, it can be heated and cooked for consumption.
Water Bamboo
Harmful Substance: Oxalic acid
Cause of Illness: Vegetables like spinach, bamboo shoots, and water bamboo contain high levels of oxalic acid. Even if they are to be eaten cold, they should first be blanched in boiling water to remove most of the oxalic acid. In the intestines, oxalic acid combines with calcium to form calcium oxalate, which is difficult to absorb and interferes with the body's absorption of calcium, leading to calcium deficiency.
Detoxification Method: Be sure to blanch them in boiling water.
Spinach
Harmful Substance: Nitrates
Cause of Illness: Vegetables like spinach and mustard greens are very good at accumulating nitrates. Nitrates themselves are low in toxicity to the human body, but under the action of microorganisms in the body, they are converted into nitrites. Vegetables like spinach and mustard greens are very good at accumulating nitrates. Nitrates themselves are low in toxicity to the human body, but under the action of microorganisms in the body, they are converted into nitrites.
Detoxification Method: They cannot be eaten raw and must be thoroughly cooked before consumption. Therefore, the "hot pot-style" method of just quickly blanching them in soup for consumption is not advisable.
Broad Beans
Harmful Substance: Vicine
Cause of Illness: Broad bean seeds contain vicine. After consuming this substance, a person can suffer from acute hemolytic anemia (favism). Poisoning often occurs when eating fresh broad beans in spring and summer if they are not cooked properly. The illness usually appears 4 to 24 hours after eating raw broad beans.
Detoxification Method: To prevent broad bean poisoning, it is best not to eat fresh, tender broad beans, and they must be thoroughly cooked before consumption.
Daylily
Harmful Substance: Colchicine
Cause of Illness: Fresh daylilies contain a substance called colchicine. Colchicine itself is non-toxic, but after being absorbed by the gastrointestinal tract, it oxidizes into a highly toxic substance called colchicine dioxide. This substance can irritate the stomach and intestines, leading to symptoms such as a sore throat, heartburn, thirst, abdominal pain, and diarrhea.
Detoxification Method: Since colchicine is water-soluble, it is destroyed during the steaming and drying process of fresh daylilies. Furthermore, dried daylily products must be soaked in water before consumption, so there is no risk of poisoning.