When growing up, I was always told that onions make us cry because the farmer was angry when he planted them. The angrier the farmer, the stronger the onion. This, of course, is not true. Crying from cut onions is a response to chemicals released from the ruptured cells of the onion. Here is a breakdown of what exactly happens from onion to tears:
1. When the knife cuts into the onion it ruptures cell walls of the onion. Inside the cells are amino acids and allinase enzymes. When these two substances mix in the air, they form sulfenic acids.
2. Sulfenic acids are very unstable. They exist for a short time before converting themselves into thiosulfinates and a gas called syn-propanethial-S-oxide. Since syn-propanethial-S-oxide gas is so hard to pronounce, it is commonly known as the Lachrymatory Factor.
3. As the Lachrymatory Factor moves through the air, it comes into contact with our eyes. When it touches the cornea it contacts autonomic nerves that lead to our lachrymal glands. Our lachrymal glands, when activated, automatically release tears into our eye to flush away whatever is irritating them.
4. As our eyes fill with tears, we blink to wash the tears and the irritant out of our eyes, causing crying.
As the Lachrymatory Factor reaches our eyes, we feel like we want to rub them. If we do, it only causes us to cry more because there are more irritants on hands. To avoid crying while cutting onions, a few methods have proven to work for some people:
1. Cut fast before the fumes reach your eyes.
2. Chew gum. This forces us to breathe through our mouths, sucking up some of the gas.
3. Cut onions under running water – a difficult task.
4. Wear goggles.
Posted 4521 day ago