Why do we cry while chopping the onions?

 Why do we cry while chopping the onions?

Ever cut of an onion and started tearing up? Most people do. It turns out when you cut an onion, it releases a gas called,  Propanethiol S-oxide. When mixed with certain enzymes in the onion, it creates a sulfur gas. These gases then get to your eyes and create a mild acid which irritates the eyes.Normally, your body would signal you to close your eyes. This, of course, is not a good idea if you are cutting an onion. The next best thing your eyes can do is to make tears to protect the eyes. Rubbing your eyes is a bad idea, since your hands are likely full of the tear making onion juice. So how do you keep from tearing up? There are many theories out there. I’ve heard some have had luck burning a candle near the chopping site. (Don’t try that without an adult.) Wearing safety goggles, however, should reduce the tears every time.

The whole process goes as follows:-

1. Lachrymatory-factor synthase is released into the air when we cut an onion.
2. The synthase enzyme converts the amino acids sulfoxides of the onion into sulfenic acid.
3. The unstable sulfenic acid rearranges itself into syn-ropanethial-S-oxide.
4. Syn-propanethial-S-oxide gets into the air and comes in contact with our eyes. The lachrymal glands become irritated and produces the tears!

Related Searches Websites:-

• Cooking Onions Without Crying  - From the University of Nebraska-Lincoln Extension.
• National Onion Association - This website provides onion information & tips, recipes, growing areas, and industry. "The National Onion Association encourages the United States onion industry to voluntarily exercise all reasonable efforts to supply consumers with the highest quality, most nutritious, and safest onions available; and furthermore, to grant appropriate consideration and respect to the issues of food security, sound pesticide management, and environmental stewardship."
• NPR Story: Exploring the Stinky Science of Alliums - July 2, 2010 interview with Eric Block author (and chemist) of Garlic and Other Alliums: The Lore and the Science(2010).
• Onions - This site from Texas A&M University provides all types of information about onions such as planting tips, the varieties, the history and laws, and onion recipes.
• Why Do Onions Make You Cry?  From PennState Extension.

Protection from Tears while cutting the Onions:-

1. Use a sharp knife. A sharp knife will cause less damage to cell walls, and fewer irritants will be released.

2. Keep the exposed cuts away from you. As soon as you cut an onion in half, turn both halves down on your cutting board. Leave the side you aren't currently chopping unpeeled. Once you've finished with one half, move the diced onion into a prep bowl, and set it on the opposite side of the kitchen, before proceeding with the rest of the onion.

3. Cut the onion properly. Chefs have an efficient way of dicing onions which conveniently keeps the most of the exposed cuts against the board. This Chow video will walk you through the process.

4. Chill the onions. With a cold onion, less propanethial S-oxide will evaporate. You'll still get some irritants, but this will help. Remember – refrigerate, don't freeze. Frozen raw onions are often mushy when they thaw.

5. Run the vent hood. Position your cutting board next to the stove and turn on the exhaust fan. Irritants will be pulled away from you and your eyes.