Can the green onions that fade after rubbing it?
Expert: Possibility of poisoning is unlikely, it is recommended to rinse several times before eating
Recently, citizens in many cities have bought "fading green onions" when shopping for vegetables, which has aroused widespread concern.
In fact, as early as January this year, the blue onion can be wiped out with a paper towel, and it has already appeared in everyone's sight.
The name "Bordeaux mixture" of this blue substance is also known by so many ordinary consumers for the first time.
Yesterday morning, the Qianjiang Evening News WeChat public account tweet reported the matter again, and a few hours later, it had read more than 100,000.
Some readers reported that they also bought "fading green onions" at their doorstep.
Therefore, a reporter from the Qianjiang Evening News visited this.
Hangzhou market does have "fading green onions"
The remaining blue is a commonly used fungicide
According to the reader's clues, the reporter went to the farmer's market in the sixth district of Chaohui, Hangzhou, and did not see the green onions for two rounds. After asking a stall owner, he took out a handful of green onions.
"There are few people buying green onions, so I won't let them out. One dollar."
The reporter took a closer look at the green onions, and indeed, even if you don't use paper towels to wipe them, you can see with the naked eye that there are some blue substances remaining on the green onions, in the form of water stains.
Wipe with a paper towel, you can see a faint blue trace.
What is this blue substance?
The market supervision department stated that this is Bordeaux mixture, also known as "blue vitriol", which is made of hydrated copper sulfate and a mixture of quicklime.
Bordeaux mixture is a kind of pesticide with high safety. Its active ingredient is basic copper sulfate, which can prevent infection of germs. It has the characteristics of wide sterilization spectrum, long validity period, no antibodies produced by germs, and low toxicity to humans and animals.
In agricultural production, it is a widely used broad-spectrum fungicide and preservative.
The bactericidal effect of Bordeaux mixture mainly comes from copper ions.
The toxicity of copper ions is mainly combined with red blood cells, causing red blood cells to rupture. The most direct manifestation is hematuria, soy sauce urine and other symptoms.
In addition, copper sulfate can cause severe gastrointestinal reactions, leading to symptoms such as vomiting.
Although copper is a metal element needed by the human body, excessive intake can also be harmful to health.
In the past, the national standard set a limit of 10 mg/kg for the residual amount of copper, which was later abolished because it was "unnecessary".
Don't panic when you buy "fading green onions"
Rinse to remove residue
Clinically, there are few cases of acute copper sulfate poisoning. One is that it has a clear blue color, which is easy to distinguish, and the other is that the strong metallic taste and vomiting reaction after ingestion will prevent further eating.
Therefore, some experts believe that it is unlikely to be poisoned by eating shallots with Bordeaux mixture.
Consumers need to be reminded that they must pay attention to cleaning when buying spring onions.
Bordeaux mixture is water-soluble. Rinse it with clean water two or three times before eating to get rid of most of the residue.
It should be noted that it cannot be soaked all the time, which is not conducive to removing the residue.
Experts from the Zhejiang Academy of Agricultural Sciences said that whether the Bordeaux liquid residue on the shallots is harmful to the human body, it is necessary to consider the amount of copper residues on the shallots after normal cleaning.
But for most people, the consumption of spring onions is very small, after all, it is only used for seasoning, or to make the dishes look more delicious.
[This reduces pesticide residues]
Placement: Because pesticide residues will continue to degrade over time, some storage-resistant potatoes, cabbage, cucumbers, tomatoes, etc. can be stored for a few days after purchase. On the one hand, the agricultural products can continue to be matured, and on the other hand, pesticides will degrade residues. Will decrease.
Cleaning: Pesticide residues remaining on the surface or outside of agricultural products are also easier to be washed away by water or detergent. Therefore, soak the vegetables in water for half an hour before cooking and then rinse them with detergent, which can basically remove the pesticide residues on the surface. .
Cooking: High temperature generally degrades pesticide residues more quickly.
Peeling: The pesticide residues on the skin of agricultural products such as apples, pears, and citrus are generally higher than the internal tissues. Therefore, peeling and peeling is a good method.
Our reporter Ma Yanwen/photo