Why Onions Make You Cry

Unless you've avoided kitchen duties all your life, which I doubt, you must have cried - not because you populated the whole pot of soup or stew with enough seasoning meant for a festival(guilty of that) and got the corresponding hand of justice from your mum, but because you chopped an onion! Or, if you were as unlucky as I was, chopped lots of it!

Ever wondered why? Even with the little distance we tend to place ourselves away from the onion sometimes we still drip a few tears! Sighs... damn onion!
Luckily, I was able to get an accurate answer and finally quench my curiosity on the subject. And I'm excited to be sharing it with you. For our chemistry non-lovers this may be a good time to look away.

Okay, I'll try my best to be as comprehensive as possible without giving redundant information. I hope by the end of this post you can be able to explain why onions make people cry.

Let's go...

The onion contains

• Cells(Yes, onion have cells)
• Enzymes
• Amino Acid Sulfoxides (AAS) - These form Sulfenic acids in the onion cells.

       
 Stick with me here.

When you chop an onion, the onion enzymes are broken and mix with the Sulfenic acid to from a gas (Propanethiol S-oxide). This gas is volatile, that is evaporates easily. When this gas moves and comes in contact with your tear glands they mix with the water present there and form an acid (Sulfuric acid). It is this acid that give your eyes its burning sensation and this in turn leads to the tear glands bringing out tears. Thus you end up with watery eyes every time you cut onions at home

In summary...

Chopped onion = Enzymes + Sulfenic acid =  Gas formation

Gas + Tear Gland = Acid

Acid = Burning sensation + Watery eyes.

NB: It is the sulfur compound in the onions that also leave a typical odour of onions on your hands and utensils even after washing.

 

How Can You Prevent Tears When Chopping Onions? 

1. Turn your fan off. When your fan is on it helps spread the gas into your eyes and thus increase the burning sensation and tears formation.
2. Refrigerate your onions. Refrigerating your onions before cutting freezes the enzymes and thus prevent the complex process of sulfuric acid formation.
3. Cooking the onion inactivates the enzyme. So cook the onion after you remove the outer layer and before letting the knife touch the onion. Soak onions in water before cutting. Water absorbs the gas and you can avoid the tears. 
4. Use of goggles is also an effective way of preventing the gas from entering your eyes. 
5. Avoid cutting the onion till the root. This will prevent the mixing of enzymes with the sulfenic acids and you can spare your eyes of the burning sensation and tears  

Have any more ideas on how to prevent us from weeping uncontrollably? Please share in the comment section! My sisters will like 'em. 

Till my next post I bid you adieu. I now leave you in the hands of Will Rogers.