Onion has defense mechanism
Onions have a unique defense mechanism that protects them from being eaten by animals and microbes. This mechanism is triggered when the onion’s cells are broken down, releasing enzymes and sulfenic acid. The combination of these two compounds creates a chemical compound called syn-propanethial-S-oxide, which is responsible for the irritating gas that causes our eyes to water.How It Works
When an onion is cut or crushed, its cells break down, releasing the enzymes and sulfenic acid. The enzymes convert the sulfenic acid into syn-propanethial-S-oxide, which is a volatile gas. This gas rises up to the eyes, triggering a response from the nerves, which then release tears to flush out the foreign substance.
Why Some People Are More Affected Than Others
Some people may be more prone to tearing up when cutting onions due to individual differences in their genetic makeup, eye shape, or tear duct function. Additionally, the type of onion used can also play a role, as some onions are sweeter and gentler on the eyes than others.
Tips to Reduce Onion-Induced Tears
If you’re one of those who cry easily when cutting onions, here are some tips to help minimize the tears:
- Use a very sharp knife to minimize cell damage and reduce the release of enzymes and sulfenic acid.
- Cut the onion under cold running water or with a fan blowing towards your face to dissipate the gas.
- Cut the onion from the root end to the top, as this direction helps to minimize the release of the irritating gas.
- Chill the onion in the refrigerator for about 30 minutes before cutting to slow down the release of the enzymes.
- Try using a different type of onion, such as a sweet onion, which may be gentler on the eyes.
