Why do onions make you cry?!


Question:

Why do onions make you cry?


Answers:
Why do onions make you cry?

As any chef knows, cooking an onion produces a very strong aroma that most people enjoy. But cutting up an onion stings your eyes and makes you tear up uncontrollably. If you love to include onions in your dishes, you're probably frustrated by this all the time. So just what is it in onions that make them such an ordeal to prepare?

When you slice through an onion, you break open a number of onion cells. Some of these cells have enzymes inside of them, and when they are sliced open, the enzymes escape. The enzymes then decompose some of the other substances that have escaped from sliced cells. Some of these substances, amino acid sulfoxides, form sulfenic acids, which then quickly rearrange themselves into a volatile gas.

The gas reaches your eyes and reacts with the water that keeps them moist. This changes the chemical's form again, producing, among other things, a mild sulfuric acid, which irritates the eyes. The nerve endings in your eyes are very sensitive and so they pick up on this irritation (this is why our eyes sting when we slice onions). The brain reacts by telling your tear ducts to produce more water, to dilute the irritating acid so the eyes are protected. Your other reaction is probably to rub your eyes, but this will actually make the irritation a lot worse, of course, if you have onion juices all over your hands.

Oddly enough, this volatile compound is also responsible for a lot of the great taste in onions, as well as the pleasant aroma when you cook the vegetable. You'll also get sulfenic acids by cutting up garlic, chives and leeks, among other vegetables, but they don't form the same irritating gas, just a strong smell.

There are all kinds of remedies for dealing with this irritating phenomenon, some more effective than others. As a general rule, move your head as far away from the onion as you can, so the gas will mostly disperse before it reaches your eyes. If you really can't stand the tears, the simplest solution might be to wear goggles. This measure is very effective, but it may seem a bit extreme to those around you, and if your kitchen is steamy, you might not be able to see what you're doing (never a good idea when you're using a knife).

Peeling the onion and then chilling it in the refrigerator before you slice it will minimize the release of gas somewhat, because the change in temperature alters the compounds in the onion. Cooking an onion before you slice it will work also, for the same reason. Another easy solution is to cut the onion under water or run the tap over it as you slice.

Some people say if you hold a lemon, piece of bread or a sugar cube in your mouth, the food will absorb the gas before it reaches your eyes. Breathing with your mouth, instead of your nose, might also help because as you inhale, you suck the gas in and as you exhale, you blow it away. This keeps a lot of the gas from ever reaching your eyes.

I believe that I was told once that it was the acid in them.

This due to (sulphuric I think) acid in it.
To avoide crying peel and soak in water for a few minutes

there is an acid conversion that takes place when the onion cells are broken and exposed to air. you can run it under cold water to stop this or just deal with it

sulfur compounds release from them as their defense system from you chopping them.

What they said. See more:

The enzymes and sulfur mix when you cut an onion. Run it under cold water or freeze for 15 minutes to reduce the formation of the chemical reaction...or just pop them in a food processor.

Onions make you cry due to the sulfur content in them. I have tried running water over them, holding them under water, keeping them in the frig. and on so on. I have been using this method for several years and it works well - when possible do not cut the roots. With green onions the root is the last to be cut, when
chopping onions I do cut the whole onion in half to have a flat side for safer cutting. There are so many kinds of onions that have diff. amt. of heat in them due to the amount of sulfur in the dirt that they grow in.




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