TIP OF THE DAY: 7 Tips For Slicing Onions

November 6, 2013 at 8:10 am · Filed under Cooking, Vegetables-Salads-Herbs

For starters, slice onions vertically. Photo
courtesy Care2.com.

An onion is a thing of beauty—until you slice into it and the fumes assault your eyes.

But that doesn’t need to be. Here are some tips to minimize the impact of the acrid gas that’s released when you slice into an onion.

Go vertical. Slice the onion vertically, through the root end. The onion base has a higher concentration of sulphur compounds than the rest of the bulb.

No root. Avoid the root altogether; use only the top 80% of the onion.

Running water. Place your cutting board in the sink and cut onions under running water. The water whisks the fumes away.

More water. Submerge onions in a basin of water, if you have a basin large enough!

Cold. Refrigerate the onions before cutting. This reduces the enzyme reaction rate (see below).

Breeze. Use a fan can to blow the gas away from the eyes.

Goggles. This is our personal invention and our favorite technique: Wear swimming goggles (or any goggles). It works like a charm.

WHY DO ONION VAPORS BURN YOUR EYES?

Chopping an onion causes damage to the cells. Enzymes called alliinases—present in all members of the Allium genus*—break down amino acids (sulfoxides) and generate sulfenic acids. These further react to produce a volatile gas known as the onion lachrymatory factor or LF.

LF diffuses through the air and activates sensory neurons in eye, causing that burning, stinging sensation. Tear glands come to the defense, producing tears to dilute and flush out the irritant.

If you slice onions a lot, your eyes will become more tolerant (they may build up a tolerance to the LF).

The amount of LF differs among onion varieties. That’s why some onions are real “burners” and others are milder. Sweet onions, for example, grow in soils that are low in sulphur and don’t produce much alliinase.