Onions, a staple in kitchens worldwide, are known for their pungent flavor and aroma. However, they are also infamous for causing tears during preparation. This article delves into the science behind this phenomenon and offers some tips to prevent it.
The Science Behind the Tears
When an onion is cut, it releases a chemical irritant known as syn-Propanethial-S-oxide. This compound stimulates the eyes’ lachrymal glands, causing them to release tears. The process begins with the release of lachrymatory-factor synthase, an enzyme that converts the amino acids sulfoxides of the onion into sulfenic acid. This unstable compound then rearranges itself into syn-Propanethial-S-oxide, which gets into the air and comes in contact with our eyes, causing irritation and tear production.
This defense mechanism of onions has evolved over time to protect them from critters trying to eat them underground. When attacked, onions release sulfenic acid and enzymes, which combine to produce the irritating gas, propanethial S-oxide.
Individual Sensitivity to Onions
Interestingly, not everyone experiences the same level of discomfort when chopping onions. Some people are more sensitive to the compounds released by onions than others. This sensitivity can vary due to factors such as genetics or environmental conditions.
Tips to Prevent Crying While Chopping Onions
There are several methods to reduce the likelihood of crying while chopping onions. One common recommendation is to chill the onions before cutting them. The colder temperature slows down the release of the sulfur gas, causing less reaction with your eyes. Using a sharp knife can also help, as a dull knife can smash the onion, releasing more of the irritating compound.
Another hack involves placing a damp paper towel on your cutting board. The theory is that the acid released by the onion will be drawn to the wet paper towel instead of your tear ducts. Other methods include running the onion under water while cutting, wearing goggles, or even microwaving the onions before cutting.
Health Benefits and Risks of Onions
Despite the tears, onions offer numerous health benefits. They are rich in antioxidants and contain anticancer compounds. Studies have linked onion consumption to improved bone health, lower blood sugar levels, and a reduced risk of cancer. Onions are also believed to boost bone density and regulate blood sugar levels, making them beneficial for people with diabetes or prediabetes.
However, onions may cause digestive problems in some people and can lead to bad breath. In rare cases, they can cause allergic reactions and interact with certain medications.