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Some people are particularly particular about cooking, the pots and pans are washed cleanly, and the oil, salt, sauce and vinegar are weighed by grams, but when it comes to blanching, they often skip the trouble.
Especially when you are in a hurry or trying to save trouble, I always feel that it is not a big deal to fry or cook directly. It's really not that simple, some dishes are not blanched, which is equivalent to swallowing all the "toxins" hidden in the ingredients.
To put it bluntly, blanching is not a small action that can be done or not done, but a key step in transforming a meal from a "hidden risk" to a "safe entrance".
What exactly does blanching do? Many people think that it just makes the color of the vegetables look better and removes a little grassy smell, which has no real effect.
But in fact, blanching can help you remove some of the "harmful substances" naturally carried in vegetables, including oxalic acid, nitrates, pesticide residues, and even trace toxins naturally carried by some vegetables.
Many of these ingredients can be dissolved in large quantities by boiling for a short time at high temperatures, and as soon as the hot water is poured, the danger will follow; But if you save this step, then these "invisible toxins" may quietly accumulate in the body.
In the final analysis, blanching is a "safety door" that keeps hidden dangers out of the door, it is inconspicuous, but it is not light for health.
Vegetables high in oxalic acid
There is a misconception that many people think that oxalic acid is a "neutral ingredient", and if you eat it, it will be excreted in the urine, which is not a big deal. But the body is actually not like a vegetable washing sink, which can be easily washed away when anything comes in.
Vegetables such as spinach, amaranth, and bamboo shoots, which are frighteningly high in oxalic acid, if eaten raw or directly in the pot without blanching, will not only affect calcium absorption, but also may cause trouble such as kidney stones and urethral crystals.
Oxalic acid and calcium touch to form calcium oxalate, it is a kind of insoluble in water, not easy to be metabolized by the body of the "hard guy", long-term eating, deposited, in the kidney, bladder, urinary tube stuck in a stone, pain so that people's hair is erect.
Someone eats a big bowl of unblanched spinach vermicelli soup for breakfast every day, and after a few months, he suddenly feels low back pain, and finds out that there are two stones in his kidneys, and every time he urinates, it looks like a see.
Blanching is the easiest and most straightforward way to remove oxalic acid. The solubility of oxalic acid in water is actually quite high, as long as it is blanched in boiling water, even for dozens of seconds, a large part of the oxalic acid in vegetables can run out.
Especially spinach, which has a strong taste when eaten raw, and is easy to yellow if cooked for too long.
So it's not that blanching is a patent for "paying attention to people", it's about putting a cushion on your own body. If you save a minute or two, it may become a stone in your kidney, blocking your path for the rest of your life.
Nitrite-containing vegetables
Leafy vegetables will "spoil" after a long time, not because they turn yellow and sticky on the outside, but because nitrite begins to form on the inside.
In particular, mustard greens, oily wheat greens, coriander and other leafy vegetables with a spicy taste are not low in nitrate, and improper storage and rapid decomposition of bacteria can make the content soar within a few hours.
Nitrite binds to protein breakdown products in the stomach to form nitrosamines, which have been specifically classified as carcinogens.
There is a middle-aged man who loves to eat oily wheat vegetables and cold salad every day, which is refreshing and convenient, and he often buys a large handful of refrigerators and eats slowly for three or five days, and later finds out that the gastric mucosa has precancerous lesions.
Blanching can help with this, especially for dishes that can't be eaten on the same day. High temperatures can destroy some of the nitrite structure and kill the bacteria that cause it.
Blanching with boiling water and then cold dressing can not only delay the oxidation rate, but also dismantle those "unexploded bombs" in advance. Some experiments have even found that blanching vegetables with water above 90 °C for more than 1 minute can reduce the nitrite content by nearly half.
Many people's fear of nitrite stays on the "overnight dish", but the reality is far more complicated than that - even if you eat it on the same day, it may have already produced a considerable amount due to incomplete cleaning, exposure to the sun during transportation, etc.
At this time, blanching is not just for sterilization and odor removal, it is the lowest threshold of protection you can do.
Vegetables that contain natural toxins
Not all toxins are left behind by pesticides, and not all poisonous dishes taste weird.
Some vegetables have their own "defense system", such as green beans, wild bamboo shoots, etc., which contain natural toxins such as saponins and cyanogenic glycosides, which are originally intended to prevent insects and gnawing, but people who eat too much are also prone to accidents.
Especially like green beans, which look crisp and fresh, but there is an ingredient called "saponin" hidden in them, which can cause nausea, vomiting, gastrointestinal discomfort, and even poisoning and hospitalization.
A young man tried to save trouble, fried the green beans directly into the pot for a few minutes, and after eating a few hours, he began to have diarrhea and fever, and finally sent to the hospital for a night.
This toxin is not afraid of salt, vinegar, or oil, but of continuous heating at high temperatures. Blanching is an insurance method, even if you want to fry later, it can help you split the risk in half.
It is recommended to blanch green beans in boiling water for 3~5 minutes before boiling or frying, so as to destroy most of the saponins. The solanine on the skin of the eggplant is also a similar problem, it is active at 30 °C, but to destroy it, it needs to be processed at more than 100 °C for a few minutes, rather than "quickly stir-frying".
You can't tell if there are toxins left behind by experience, eyes and taste alone, only by temperature and time. It's like a gas leak, you can't see it, but it explodes as soon as it catches fire, and blanching is when you close the valve before igniting it.
Vegetables that are susceptible to pesticide residues
Some people think that pesticides will be clean when washed with water, and at most some baking soda and salt water bubbles will be foolproof.
However, you must know that some pesticides are fat-soluble and cannot be washed off with water or salt, such as cyhalothrin, dichlorvos and other pesticides with high residues and strong adhesion, which love to hide in the corners of vegetables, leaf fluff, and folds, and cannot reach these places by soaking alone.
Moreover, the vegetables on the market, even after cleaning, are often found to have excessive residues, especially like celery, leeks, and beans, which are used frequently and fiercely.
There was an elderly man who often eats leek dumplings, and the physical examination found that the liver enzymes were elevated, and the doctor later suspected that it was related to the long-term ingestion of trace pesticides.
Blanching is a more straightforward solution to this problem – high temperatures can destroy the structure of most toxic pesticides, especially the thermally unstable chemical composition, and when they roll in water, they are immediately decomposed or stripped from the surface of vegetables.
Experimental studies also have data support: after blanching leeks, the residue of dichlorvos can be greatly reduced. This practice is more time-saving and thorough than soaking, and is especially important for people who are used to eating large amounts of certain types of vegetables.
You may only eat a few bites at a time, but the toxins are eaten every day, and over the course of a year, there are more than trace amounts. Blanching is one of the few steps that can act on both the surface and the inside of the vegetable structure, it is not an "enhanced version" of washing vegetables, but a "safety lock" that gives you peace of mind.
It's not that these vegetables can't be eaten, but they shouldn't be treated lightly. They are like those friends who don't have a good temper, they look normal and smell fine, but once they are not handled in the right way, they turn their faces faster than anyone else.
Blanching, to put it bluntly, is not to make you more complicated, but to make it easier for the body to eat. Toxins won't make you fall down immediately, but they will slowly wear away your health.
And you, as long as you take an extra minute and blanch the hot water, you can avoid a lot of unnecessary trouble. Don't let "laziness" become an opening to sub-health, blanching is really not a loss.
The above content is for reference only, if you feel unwell, please consult a professional doctor in time
What are your thoughts on the importance of blanching? Welcome to discuss in the comment area!
Resources:
[1] Ruan Guangfeng. These 7 types of vegetables must be blanched before eating[J].Health,2023,(09):60-62.)