Why only cut onions and watery eyes, and cut garlic?

Experiencing watery eyes when cutting onions is probably a lot of people have ever experienced, especially for those who often have to cook. But do you find it strange, when the phenomenon almost doesn't happen when the green onion or garlic - the spice plants have relatives very close to the onions?

First, learn the "half-life" mechanism for the onions' eyes

Any plant, when attacked, they will defend themselves. The common defense mechanism is to produce bitter-tasting polyphenols, thereby causing the animals to eat plants to falter. But with onions, that mechanism is stronger.

Chemicals released by onions, namely propanthial s-oxide can cause strong irritation.

The chemical produced by onions - particularly propanthial s-oxide - can cause strong irritation, and more importantly, volatile . As soon as they are released, they will quickly find their way into the eye, combining with water in the cornea to form sulfenic acid. Although only with a small concentration and concentration, it is enough for the lacrimal glands to be strongly stimulated, causing you to shed tears.

In the past, science believed that onion's "semi-ophthalmic" ability came from an enzyme called allicinase - which acts as a biological catalyst, accelerating the production of propanthial s-oxide.

But actually, the mechanism is more complicated. It originates from the onion uptake of sulfur in the soil, converted into PRENCSO (1-propenyl-L-cysteine ​​sulphoxide). Allicinase will then react with PRENCSO, form ammonia and an acid. Next, another enzyme begins to synthesize these products into propanthial s-oxide - which also makes many people cry.

The reason for garlic does not cause tears

Although there are close relatives, and even the taste is more intense, garlic does not cause tears. And according to Duane Mellor - a lecturer from Coventry University (UK), the reason is that garlic contains a slightly different compound, PRENCSO 2 - or alliin.

PRENCSO 2 is different in that it will not break down the structure to become propanthial s-oxide. Instead, it stimulates allicin production - an active ingredient that is beneficial for human health.

PRENCSO 2 in garlic is different in that it will not break the structure to propanthial s-oxide.

How does tears stop flowing?

Theoretically, the defense mechanism of onions depends on the two enzymes mentioned above. So if you somehow destroy, or slow down the enzyme, the onions will no longer cause tears.

One of the most feasible ways to theoretically boil it first, then cut it and put it in the freezer. But in fact, no one handles such behavior. Another option is to store onions in the refrigerator, to slow down the production of enzymes. However, cold onions will lose the inherent flavor, while making the tubers lose their appetite.

According to Mellor, the best way is not to let those chemicals touch your eyes.Can choose cutting onions under the hood, or cutting under the tap. Also, wearing a swimming goggles or protective goggles is also an effective option.