The World's Healthiest Foods are health-promoting foods that can change your life.

Try the exciting new recipe from Day 1 of our upcoming 7-Day Meal Plan.

The George Mateljan Foundation is a not-for-profit foundation with no commercial interests or
advertising. Our mission is to help you eat and cook the healthiest way for optimal health.
Tips for Preparing Onions

Cut onions into 1/4-inch slices to cook them evenly and quickly. Let them sit for at least 5 minutes to help enhance their health-promoting benefits.

While many people love to eat onions, most dread cutting them since this process usually brings a tear or two to the eyes. The substance that causes the eyes to burn is a special gas that has been named lachrymatory factor (LF). (The full chemical name for this gas is propanthial S-oxide, and it is made from a naturally occurring compound in onion called 1-propenyl-L-cysteine sulphoxide.) Recent research has shown that LF gas is not produced through activity of onion's alliinase enzyme, but rather through the activity of a special enzyme named lachrymatory-factor synthase. Interestingly, even though lachrymatory-factor synthase is the enzyme responsible for production of LF gas, the alliinase enzyme must still be present in order for LF gas production to occur.

Of course, no sooner had this new tear-producing enzyme been discovered than researchers began looking for ways to switch off the gene that served as the blueprint for this enzyme. However, "silencing" the gene without compromising the health benefits of the onion turned out to be a difficult task. Even though researchers in Japan succeeded in shutting down the gene and preventing production of lachrymatory-factor enzyme (thereby paving the way for a genetically engineered onion that would not produce LF gas and cause tearing), they also determined that the shutdown of the gene caused significant (and mostly unwanted) changes in the overall mixture of sulfur-containing molecules in onion.

If cutting onions irritates your eyes, there are a few tricks that you can employ. Use a very sharp knife and always cut the onions while standing; that way your eyes will be as far away as possible. Consider cutting onions by an open window. If cutting onions really makes you cry, consider wearing glasses or goggles. Chill the onions for an hour or so before cutting; this practice can slow down the onion's metabolism and thereby lessen the rate of LF gas production. Cutting onions under cold, running water is a method that is often used to cut back on eye irritation, but it's a method we view as a second-best choice since some of the nutrients found in onion can be lost into the flow of water.

Printer friendly version

Send this page to a friend...

rss


Newsletter SignUp

Your Email:

Find Out What Foods You Should Eat This Week

Also find out about the recipe, nutrient and hot topic of the week on our home page.

 

Everything you want to know about healthy eating and cooking from our new book.
2nd Edition
Order this Incredible 2nd Edition at the same low price of $39.95 and also get 2 FREE gifts valued at $51.95. Read more


Healthy Eating
Healthy Cooking
Nutrients from Food
Website Articles
Community
Privacy Policy and Visitor Agreement
References
For education only, consult a healthcare practitioner for any health problems.

We're Number 1
in the World!

35 million visitors per year.
The World's Healthiest Foods website is a leading source of information and expert on the Healthiest Way of Eating and Cooking. It's one of the most visited website on the internet when it comes to "Healthiest Foods" and "Healthiest Recipes" and comes up #1 on a Google search for these phrases.

Over 100 Quick &
Easy Recipes

Our Recipe Assistant will help you find the recipe that suits your personal needs. The majority of recipes we offer can be both prepared and cooked in 20 minutes or less from start to finish; a whole meal can be prepared in 30 minutes. A number of them can also be prepared ahead of time and enjoyed later.

World's Healthiest
Foods
is expanded

What's in our new book:
  • 180 more pages
  • Smart Menu
  • Nutrient-Rich Cooking
  • 300 New Recipes
  • New Nutrient Articles and Profiles
  • New Photos and Design
privacy policy and visitor agreement | who we are | site map | what's new
For education only, consult a healthcare practitioner for any health problems.
© 2001-2017 The George Mateljan Foundation, All Rights Reserved