REVENGE OF THE ONION: PASS THE TISSUES

WRITER: FRED HILTON

The poor onion is the Rodney Dangerfield of the food world. It gets no respect. The onion is left out of all those great food expressions. Why is New York the Big Apple and not the Big Onion? Why is he “a peach of a fellow” and not “an onion of a fellow?” Why is it “cool as a cucumber” and not “cool as an onion?”

Onions have undergone linguistic abuse forever, but the noble onion knows how to strike back. Onions make us cry. We have known for a long time that if you chop onions, your eyes are going to tear up. However, what causes that nasty side effect?

It’s actually acid — a form of sulfuric acid like the stuff that is in your car battery.

Dr. Anne Marie Helmenstine, a freelance writer and scientific consultant with a biomedical sciences background, explains the phenomenon: “When you cut an onion, you break cells, releasing their contents. Amino acid sulfoxides form sulfenic acids. Enzymes that were kept separate now are free to mix with the sulfenic acids to produce propanethiol S-oxide, a volatile sulfur compound that wafts upward toward your eyes. This gas reacts with the water in your tears to form sulfuric acid. The sulfuric acid burns, stimulating your eyes to release more tears to wash the irritant away.”

However, not all onions are created equal. The sweet Vidalia onion, for example, has lower levels of sulfide and doesn’t produce anywhere near the level of tears that other onions do.

There are a number of ways to avoid the tears caused by onions. Keep the kitchen fan running while chopping onions. The constant air circulation spreads the gas thinner and reduces the burning sensation in your eyes. You can also refrigerate the onion before cutting it. The colder temperatures slow the chemical reaction that creates the gas. As a last resort, you can wear goggles — effective but it does make you look pretty silly.

Onions are well worth a little discomfort, though. They are incredibly tasty on your hot dog or hamburger. And there’s more good news: onions are chock full of health benefits. The National Onion Association says, “High in vitamin C, onions are a good source of dietary fiber and folic acid. They also contain calcium, iron, and have a high protein quality. Onions are low in sodium and contain no fat.”

This news should come as no surprise, since we all remember the old saying:

“An onion a day keeps the doctor away.”