What does cutting onions have to do with tears?

What does cutting onions have to do with tears?

There is no doubt that onions are one of the best food items that add a delicious and delicious taste to meals, whether they are grilled, fried, cooked or raw, in addition to containing many nutritional benefits for the body.

However, he has a "disturbing" character, as he directs his only defense against those who chop him up, and "revenges" everyone by making them cry before facing his inevitable end. What is the secret behind that?

Scientists call onions the tear factor, which is a chemical that severely irritates the eyes.

Onions in their natural (uncut) state contain two separate compounds, “cysteine ​​sulfoxides” and an enzyme called “alinase”.

But when it's sliced, diced, or crushed, the barrier separating these two compounds breaks, and the two come together, creating a reaction. The enzyme allinase converts cysteine ​​sulfoxides into sulfonic acid, a sulfur compound.

Sulfuric acids have two options

Josie Silveraroli, Pharm.D. from Ohio State University and first author of a 2017 study published in the Journal of the American Chemical Society “CS Chemical Biology,” on the lacrimal factor in onions, said, “Sulfuric acids have two options: the first option is that they can It spontaneously condenses and reacts within itself, becoming an organosulfur compound.”

Silveraroli explained to the scientific journal "Live Science" that "organic sulfur compounds are what give onions its strong smell and flavor," noting that "a similar reaction occurs in garlic, and for this reason it has a pungent flavor."

And he added, “But the second choice of sulfonic acid is unique to onions and another pair of Allium (a genus of plants), or a genus of flowering plants that produce vegetables such as onions, garlic, green onions and leeks,” noting that “there is another enzyme called tear factor synthase, It hides in the cell and plays a role, rearranging the sulfonic acid in the lacrimal factor.”

volatile liquid

He also added that “the tear agent is a volatile liquid, which means that it turns into vapor very quickly. Thus, it reaches your eyes and irritates the sensory nerves, and the eye begins to secrete tears to get rid of irritants.”

He stressed that "it is possible that both the organosulfur compounds that give onions their intense flavor and the tear factor have evolved as defense mechanisms in these plants," noting that "their purpose is to stop insects, animals or parasites that may damage the onion plant."

What are the solutions?

According to "Live Science" magazine, it is advised to wear protective glasses or lenses when cutting onions, or anything that could form a barrier between the onion and the face.

She also pointed out that the sharp knife contributes to the destruction of a small number of cells, which significantly reduces the secretion of this compound and alleviates the problem.