One of the most common problems in the kitchen is the tears that flood our eyes when we cut an onion. It’s one’s fault volatile substance call tear gas factor (syn-propantial-S-oxide): it is produced by some enzymes present in the onion cells when we damage the plant cells with the knife. The tear gas factor is indeed irritating for our eyes and stimulates the production of tears. Science has studied this phenomenon and thought of gods mechanisms to avoid crying when we slice onions: either we reduce the formation of the tear gas factor or we prevent it from reaching the eyes. Cool the onion, use a sharp knife, work with waterfall or in environments ventilated And physically protect your eyes These are some of the methods proposed to reduce the dispersion of irritating substances.
How not to cry when cutting an onion
1. Cool the onion
According to some studies, keep the onion in the fridge before cutting it slow down the enzymatic reactions and therefore the production of the tear gas factor. It’s a bit like “putting the brakes” on the defense of the bulb.
2. Use a sharp knife
Blunt blades and rapid movements increase the amount of vapors released, according to a study published in PNAS: the more we “shake” the knife inside the onion (perhaps because the knife does not have an excellent blade), the more we risk damaging the plant cells by stimulating the release of the substance. A slow and clean cutwith a good blade, produces less irritating aerosol.
3. Use water
THE’waterfallas usual, can lend us a hand, diluting the tear gas factor and taking it away. In practice the task of water is push it away as much as possible before it irritates your eyeballs. National Geographic, for example, recommends using a wet knife (perhaps rinsing it after each cut, making sure to act near the kitchen sink to avoid further spreading the tear gas factor into the air) or, better yet, slicing the onion directly under running water.
4. Ventilate the room
Another option, often recommended, and also present among the National Geographic recommendations, is to cut the bulb under a extractor hood or near a fanobviously taking care not to direct the jet of air towards us. The tear gas factor it is in fact very volatile, that is, it easily tends to pass into the air: operating in a ventilated environment helps disperse the vapors It significantly reduces the likelihood that it will fly towards our eyes and irritate them.
5. Wear eye protection
It may seem like a bizarre and banal idea, but wear tight-fitting glasseslike those for swimming pools, is among the most effective methods: if the tear gas factor does not reach the eyes, it cannot irritate them.
Each of these suggestions can help us avoid crying while chopping our onions, but if joined together (protected eyes + cold onion + cutting under running water + open window for ventilation) will certainly be more effective in avoiding this annoying problem. Not only that, it would appear that scientists are working on “modified” onions without the “culprit” enzymes of the release of the lachrymatory factor. Who knows, maybe in some time we will be able to cut them without shedding a single tear!
