Why does chopping onions make you cry?

It's not tears of joy that you shed while preparing these beloved bulbs.Hmmm… countless times already that I experienced tears just dropping while cutting onions…and that’s why I wondered, why this thing makes me cry? It’s interesting, isn’t it? As what the article said that you can have whole onions sitting around your house for days, even weeks, and everything is just fine. But when you try chopping it even just a small onion…you can't help but say..ouch! Stinging , burning and crying (oh, my!) like you wouldn’t believe. Hehehe

So here’s the answer why?: I just read this article today and I want to share this discovery to my fellow bloggers.

Lachrymatory-factor synthase, an enzyme that was discovered by Japanese researchers in 2002, is released when you cut into an onion. This enzyme converts the onion's sulfoxides into sulfenic acid. The sulfenic acid rearranges itself into an unstable compound known as syn-propanethial-S-oxide. Once this compound reaches our eyes, it irritates them, causing the crying reflex to kick in to flush out the irritants.

Additional infos:

There are three types of tears — basal, reflex and emotional. Basal tears keep your eyes from drying out, like on a windy day. Reflex tears clear your eyes of irritants, such as when you get dirt in your eye. And finally, emotional tears can be a result of happiness, sadness or any other emotion that gets your cry on.

The kind of tears you’re producing when you’re chopping onions is reflex tears, because your brain is sending the message to your eyes to flush out the unstable compound mentioned above.

So is there anything you can do to prevent it?

Well, a scientist at New Zealand’s Crop and Food Research Institute by the name of Colin Eady is working on creating a tear-free onion. That’s right, folks — no more crying. Using gene-silencing technology, Eady was able to shut down the lachrymatory-factor synthase gene and create an onion that did not induce tears. The onion is a long way from grocery store shelves, but we could be on our way in the next few years.

Until then, here are some other things you can try:

First, try sticking your onions in the refrigerator for a few hours before you cut them. Or the National Onion Association (yes, there is one) suggests cutting the top end of the onion off and peeling downward, but cutting off the root end (the one with all the hair on it) last. This is because the cells that release the onion's bountiful sulfur are concentrated at the base. It also might help to peel the onions under water.
Hmmm...good luck chopping!