Why Onions Make People Cry

I love to put onions on my fried rice, corned beef and everything else. The problem is they make tears.

There’s a chemical process involved in chopping onions. Allium cepa has allinases, enzymes that break down amino acid sulfoxides. These molecules become two kinds of molecules: sulfenic acids and thiosulfinates. First, the sulfenic acids spontaneously rearrange into syn-propanethial-S-oxides which trigger the tears. The thiosulfinates, on the other hand, are the chemicals that cause the odor.

So, what do we do to stop the tears?

The onions can be heated, in microwave or in boiling water. Leave the enzymes to be degraded for even 5 minutes. I find it rather clever, actually. Simple, but really clever.

~ by figsch on June 27, 2008.