Onion why make you cry

The tears you shed while chopping onions are not caused by any type of emotion. Before you cook another stir-fry, read on to learn why onions make you cry and how to avoid the tears that come with preparing this popular kitchen staple. Onions are bulbs that mature underground. To stop this from happening, onions are equipped with a defense mechanism designed to protect them as they grow from hungry animals.

Onions spew enzymes and sulfenic acid when their skin is broken. These compounds combine to produce propanethial S-oxide , an irritating gas. Propanethial S-oxide is a lachrymatory agent, meaning that it generates tears when it touches the eye. Propanethial S-oxide turns into sulfuric acid when it touches the water layer that covers and protects your eyeballs.

But just like onions, your eyes are also equipped with a defense mechanism meant to protect them from harm. When the nerves in each eye detect a lachrymatory agent, they generate tears to flush it out. Some people are more likely to cry when cutting onions than others. The onions that generate the harshest chemical reaction have lots of sulfur-containing compounds. These include yellow, red, and white onions. Sweeter types, such as green onions , have less sulfur, are less pungent, and produce fewer tears in most people.

Through genetic transformation, crop scientists have also created tear-free onion varieties. While not yet mass-produced, you can find tear-free onions called Sunions in some specialty markets. Here are some tips to reduce crying from onion irritation:. First, keep in mind that the length of time you store onions affects their potency and tear-producing abilities.

Fresher onions are less likely to cause crying than those that have been stored for an extended period of time. However you slice them, try to avoid cutting your onion near the root end. This is the part that contains the highest concentration of sulfuric compounds that can make you cry.

Using a sharp knife may also help. The sharper the knife, the less damage is done to the onion, and fewer irritations are released into the air as a result. To reduce or eliminate onion tears, you may have the best luck if you diminish the sulfuric acid compounds in the onion itself. This gas reacts with the eyes to form small amounts of sulfuric acid. Sulfuric acid can lead to itching, burning — and tears. But the process is more complicated than that. He and other scientists have been struggling to come up with the full picture for more than 40 years.

Block has been working on the problem since the s. The structure of any molecule shows the position of the different atoms that make it up.

That structure also shows how the different atoms join together. He knew that LF must start off as a different molecule. He hypothesized that a chemical reaction must take place as an onion is cut. Block thought this chemical reaction must convert a stable molecule into one that could quickly vaporize and burn the eyes. Sometimes chemical reactions need a little help to get started. Enzymes help to jump-start or speed up chemical reactions.

Block focused on an enzyme known as alliinase AL-ee-un-ace. He showed that it helped to speed up the chemical reaction that converts sulfoxides Sul-FOX-ides — stable starter molecules in the onions — into eye-irritating ones.

Certain plants, such as garlic and onions, make alliinase. It helps make the volatile chemicals that give these foods their savory flavors and aroma. Cutting the onions in half or quarters before soaking them is even more effective. Wear swimming goggles or ski goggles while cutting the onion.

Use a ventilator or fan to blow the allyl sulfide away. What is amino acid? What is enzyme? What is a catalyst? A substance that alters a chemical reaction without being affected itself. What is the white powder strewn onto the streets when snow falls? What causes a disposable portable body warmer to heat up become warm?

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