Onion: Hi, are you crying?

Onion (Allium cepa) is native to Central Asia or West Asia. It is a biennial herb of the Allium genus in the Amaryllidaceae family. It is a popular food material, whether it is in stir-fries, stews, or salads. . But why is it that we inevitably cry when we chop an onion?

How do onions make people cry?

When we cut an onion, the onion cells are destroyed and release a chemical calledAlliinase (alliinase)of enzymes. Alliinase is present in the vacuole (vacuole) of the onion cell, which isolates it from other intracellular substances. Once the cell wall is disrupted, alliinase comes into contact with the substrate 1-propenyl-L-cysteine sulfoxide (PRENCSO). Under the catalysis of alliinase, PRENCSO will be converted into the intermediate product 1-propenylsulphenic acid, which will be rapidly decomposed into two chemicals, propanthial-S-oxide (propanthial S-oxide) or thiosulfite (thiosulfinate).Propylthioaldehyde-S-oxideIt is a volatile gas, it will evaporate into the air quickly, when it comes into contact with our eyes, it will irritate the cornea, and then cause the lacrimal gland to burst into tears, which is the main reason why we cry when we cut onions.

The pungent gas emitted by onions is actually a self-protection mechanism, because the smell is very unwelcome to many insects and animals, and the onions can escape if they go well. But for humans, the top predators in nature, this is just a meaningless struggle. No matter what kind of irritating gas or disgusting smell they emit, they have to eat you when they should eat you. What do you think? There is no escape.

How to avoid tears

1. use sharp knives: Sharp eyes and quick hands, quick resolution, sharp knives can reduce the irritating gas produced when onion cells rupture, thereby reducing the probability of crying.
2. First soak the onion in cold water: Soak the onion in cold water before cutting it, which helps to reduce the activity of alliinase, thereby reducing the generation of irritating gas.
3. chilled onions: Refrigerate the onion for 15 minutes before cutting. Refrigeration will reduce the activity of the enzyme. The principle is the same as the second point.
4. Use a range hood or keep it ventilated: When cutting onions, turn on the range hood or keep ventilation, so that the irritating gas can quickly dissipate to reduce the chance of contacting the eyes.
5. wear glasses or goggles: Wearing glasses or goggles can block some irritating gases from entering the eyes and reduce the chance of tear collapse.

Although onion is moving, it is actually a plant with very high nutritional value!

In addition to adding flavor to dishes, onions are also a plant with very high nutritional value:

1. Antioxidant and anti-inflammatory: Onions are rich in various antioxidant and anti-inflammatory substances such as flavonoids, polyphenols and sulfides. These compounds fight free radicals, reduce oxidative damage and lessen the body's inflammatory response, helping to prevent chronic disease and aging.
2. improve cardiovascular disease: Quercetin and other ingredients in onions may have the effect of expanding blood vessels and lowering blood pressure.
3. prevent cancer: Quercetin, kaempferol and other antioxidants in onions are believed to have certain effects on the prevention of certain cancers.

Is anyone not fit to eat onions?

While onions are a healthy food for most people, there are some situations in which onion consumption may need to be limited or avoided:

1. allergic reaction: Generally speaking, onion is a safe vegetable, but if you are allergic to it, don’t eat it.
2. GI sensitivity or hyperacidity: Onions may cause irritation to the gastrointestinal tract, leading to increased stomach acid, aggravating problems such as heartburn, gastric ulcers or stomach pains.
3. drug interaction: Onions may affect the absorption or metabolism of certain medications. If you are taking certain medications, especially anti-clotting medications or certain medications for chronic diseases, it is best to limit the amount of onions in your diet and discuss with your doctor whether you can eat onions.

Are onions a pet killer?

Onions are a taboo food for some pets, especially cats and dogs, because onions contain a sulfide called N-Propyl Disulfide. Excessive consumption of onions by pets will cause red blood cells to be destroyed, resulting in hemolytic anemia. Pets die. In order to protect your beloved pets, it is best to keep onions or foods containing onions away so that babies do not eat them by mistake.

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References

1. onion- Wikipedia

2. Narges Marefati, Vahideh Ghorani, Farzaneh Shakeri, Marzie Boskabady, Farzaneh Kianian, Ramin Rezaee, and Mohammad Hosein Boskabady. A review of anti-inflammatory, antioxidant, and immunomodulatory effects of Allium cepa and its main constituents. Pharm Biol. 2021; 59(1): 285–300.

3. The 5 major nutritional benefits of onions, the advantages and disadvantages of eating raw onions? Taboo, save it once – Chen Weicheng

4. Onion tears do not cry! ? Onions that no longer make people cry! – Teacher Black Bear

5. The pictures in the article are all from the CC0 free gallery.