Put the onion in the freezing layer, freeze for about 15 minutes before cutting. Freezing is not easy to destroy the smell of onions, but also can reduce the production of irritants. Cut onions in a naturally ventilated area, for example, blow directly with a mobile electric fan, or turn on the range hood to avoid contact with the irritating steam of onions as much as possible. You can also cut onions in a closed container. However, when we cut onions, some people cry. If we master some skills, we won't cry when cutting onions: freeze them in the refrigerator for half an hour before cutting them. Cut the onion in half, soak it in cold water for a while, then cut it.

It is also effective to interrupt the cleaning of fruit knives with cold water. Put some salt on the surface of onions, and then cut them. Onions contain a chemical called alliinase. When the onion is cut, the released alliinase will react with some carbohydrates in the onion to form unstable sulfinic acid. Hyposulfonic acid quickly becomes a volatile gas, which stimulates the peripheral nerves in the cornea. The feedback mechanism is transmitted to the human brain, which makes a judgment, and then sends an order to the lacrimal gland located in the corner of the eye to let it metabolize tears to wash away such stimuli.

This is the main reason why you can't help crying when cutting onions. Onion is a low-fat and low-sugar food with high water content, so it is suitable for dieters or patients with three highs. In addition, onion also contains sulfur compounds, prostacyclin A, flavonoids, ginsenoside, phenols and other plant active ingredients. Sulfur compounds are responsible for the sweetness and pungent smell of onion, which is the only known vegetable containing prostacyclin A. Flavonoids and phenolic compounds are the most important antioxidant components in Allium plants.

Most of the functions of onion circulated among the people come from the functions of these substances. Refrigerate or even freeze onions before cutting them to reduce the enzymatic reaction in onions; Microwave heating, putting the onion in a microwave oven for 20-30 seconds, destroying the enzyme in the onion, taking it out and cutting it, so that it is not easy to shed tears; No matter what protective measures you take when cutting onions, you will be defeated by onions in the end. The same is true of protective glasses when swimming. I still remember someone saying that cutting onions in water is not easy to irritate the eyes. But through the test, it is found that the premise of cutting onions in water is that you have such a knife.