I tear up when I am chopping onions, and even though sometimes it’s just a sniffle, there have been times — like when I am on a marathon chopping streak while making multiple freezer lasagnas — when the tears just started to flow.
What in the world is happening?
According to Mental Floss (a fantastic magazine and blog):
1. When you cut into an onion, its ruptured cells release all sorts of goodies, like allinase enzymes and amino acid sulfoxides. The former breaks the latter down into sulfenic acids.
2. The sulfenic acids, unstable bunch that they are, spontaneously rearrange into thiosulfinates, which produce a pungent odor and at one time got the blame for our tears. The acids are also converted by the LF-synthase enzyme into a gas called syn-propanethial-S-oxide, also known as the Lachrymatory (crying) Factor.
3. Syn-propanethial-S-oxide moves through the air and reaches our eyes. The first part of the eye it meets, the cornea, is populated by autonomic motor fibers that lead to the lachrymal glands. When syn-propanethial-S-oxide is detected, all the fibers in the cornea start firing away and tell the lachrymal glands to wash the irritant away.
4. Our eyes automatically start blinking and producing tears, which flushes the irritant away. Of course, our reaction to burning eyes is often to rub them, which only makes things worse since our hands also have some syn-propanethial-S-oxide on them.
It only takes about 30 seconds to start crying after you make the first cut, that’s the time needed for syn-propanethial-S-oxide formation to peak.
One of Mental Floss’s recommendations to avoid crying is wearing swimming goggles, which might be a great solution (since they block out everything around the eye due to their tight fit), but they can also leave unsightly red rings around your peepers — which isn’t cool when you have guests coming, or worse — already there! So another solution would be … Onion Goggles!
These fog-free clear lensed goggles are sure to keep your eyes dry next time you are cooking with onions. The frames are lined with a comfortable foam seal that protects eyes from onion vapors as you mince, dice and slice. Also use them to when chopping onions kin such as leeks, scallions and chives. Their unisex design fits most face shapes and they come in a handy storage case to keep your goggles clean and scratch free when not in use.
Brilliant! You can chop onions tearlessly, keep from looking like a raccoon, and avoid flying objects hitting your eyes all at the same time! And you can get your own pair for $19.95 at UsefulThings.com.