Table of contents:
- Crying when cutting onions does not come from the smell of onions
- Tips and tricks so that your eyes don't sting when cutting onions
- 1. Chop the onion in water
- 2. Freeze the onions
- 3. Spread the lemon juice along the knife
- 4. Cut the onions near the open vents
- 5. Use an onion slicer
Unless you are someone who is anti-kitchen, you may have had tears in your eyes from chopping onions. Have you ever wondered why we cry when we cut onions?
Crying when cutting onions does not come from the smell of onions
Onions - red, white, onions - are enriched with vitamins C, B1 and B6, along with high doses of potassium, phosphorus and fiber. Although not everyone likes onions, this spice that is included in this Allium plant species has the potential to fight bad cholesterol, reduce hypertension, and minimize blood clots.
On the other hand, the essential oils that help give onions their distinctive taste contain a group of organic molecules called amino acids sulfoxides. Peeling, chopping, or grinding onions releases the enzyme lachrymatory-factor synthase, which converts these molecules into sulfenic acid. Sulfenic acid, then spontaneously rearranged to form syn-propanethial-S-oxide. When syn-propanethial-S-oxide (a combination of sulfuric acid, sulfur dioxide, and hydrogen sulfide) enters the air around your nose and face, this group of compounds evokes a tear-jerking reflex.
The front surface of the eye - the cornea - serves several purposes, including protection against physical and chemical irritants. The cornea is populated by various sensory fibers from the ciliary nerve, branches of the large trigeminal nerve (which carries touch, temperature), and painful sensations from the face and front of the head. The cornea also receives a small number of autonomic motor fibers that activate the tear glands (tears). The free nerve endings detect syn-propanethial-S-oxide in the cornea and induce activity in the ciliary nerve - which is interpreted as a sensation of heat by the central nervous system - according to the concentration of this compound. This nerve activity reflexively activates the autonomic fibers, which then carry signals back to the eye ordering the tear glands to flush clean the foreign irritants.
The syn-propanethial-S-oxide formation reaction peaked about 30 seconds after mechanical breakdown of the onion and completed its chemical evolution for about 5 minutes.
These active compounds also condense themselves to form smelly thiosulfinate, coincidentally triggering the release of the pungent odor associated with chopping onions, giving rise to the false accusation that the cause we cry comes from smelling them. In fact, the thiosulfinate enzyme uses a completely different chemical pathway, it doesn't affect the eyes.
Tips and tricks so that your eyes don't sting when cutting onions
If you use a lot of onions when cooking, then chances are that you've already explored 1001 ways to avoid this annoying problem. And, the internet today is filled with a variety of ways, from the seemingly normal (wearing swimming goggles while chopping onions) to the slightly bizarre (biting a matchstick?). So, which ones are really effective?
1. Chop the onion in water
Looks a little dangerous, indeed. But, chopping the onions under water will prevent the sulfate compounds from reaching your eyes and causing you to cry. If you want to try this method, use a safety precaution - use a flat, wide alcove container (such as a baking sheet) to provide maximum work space or try placing your chopping board in the sink and chopping the onions under cool running water.
2. Freeze the onions
Leaving the onion 15 minutes in the freezer will reduce the irritation level as you cut the onion later, but this trick makes chopping more difficult (because it is frozen) and it will be difficult to peel off the outer layer of the onion. The taste, still nothing to lose to try, right?
Alternatively, you can heat the onions for a few seconds in the microwave before chopping them. The principle is the same, hot temperatures will inhibit the irritation process.
3. Spread the lemon juice along the knife
Cut a lemon in half and rub the lemon juice on the blade before cutting the onion. However, you will need to repeat the basting every few chunks.
4. Cut the onions near the open vents
Or, why not chop the onions in the breeze from the fan? In addition to fighting sweat, the wind will blow sulfuric compounds away from your eyes.
5. Use an onion slicer
When nothing else works, why not use a special onion slicer that will keep you from coming into contact with the steam of the onions, the main culprit behind your tears?
One thing is for sure, cooking onions kills the enzymes, so even if the smell of onions is still strong when they are cooked, it will not irritate your eyes.
