1, vegetables rich in nitrate
Vegetables such as mustard are very easy to enrich nitrate. Nitrate itself is less toxic to human body, but under the action of microorganisms in human body, it will be transformed into nitrite, which will combine with nitrogen-containing compounds in gastrointestinal tract to form a strong carcinogen-nitrosamine, which has great risk of inducing cancer in digestive system. This vegetable must be boiled in boiling water before it can be eaten.
2. Vegetables with more oxalic acid
Spinach, bamboo shoots, water bamboo and other vegetables contain more oxalic acid. Even if you want to make a cold salad, you should first blanch it with boiling water to remove most of the oxalic acid contained in the vegetables. Oxalic acid will combine with calcium in the intestine to produce calcium oxalate which is difficult to absorb, which interferes with the absorption of calcium by human body and leads to calcium deficiency.
3. Wild vegetables
Wild vegetables such as purslane need to be blanched with clear water first to completely remove dust and insects and prevent allergies. In addition, water chestnut, lettuce and other vegetables are best peeled and washed before being recycled, which is more hygienic and will not affect their taste and nutritional value.
4. Starch vegetables
Starch-containing vegetables, such as taro, potato, yam, etc. Be sure to cook it, otherwise the starch particles inside will not break and the human body will not digest it. People with weak gastrointestinal function can also cause severe indigestion.
5. Green leafy vegetables growing underground
Under conventional cultivation conditions, this kind of vegetable is often watered with human and animal manure and pesticides, which is easy to pollute the vegetable and it is impossible to wash it with clean water anyway.
People's Network-Don't eat five kinds of vegetables raw? Otherwise, food poisoning may occur.