Why do you shed tears when you cut onions?

When chopping onions, many onion cells will be destroyed. Some of these cells contain enzymes that escape when cells divide. Then, the enzyme will break down some other substances that escape from the divided cells. Some of these substances (sulfoxide) form sulfinic acid. Then, the hyposulfonic acid quickly recombines and becomes a volatile gas. Gas reaches people's eyes and reacts with water that keeps them moist.

This changes the form of chemicals again. One of the substances produced is called sulfuric acid, which can irritate the eyes. The nerve endings in the eyes are very sensitive and will feel this kind of stimulation (which is why our eyes sting when we cut onions).

Then the brain responds by telling the lacrimal gland to secrete more water to dilute the irritating acid to protect the eyes. Our accompanying action may be rubbing your eyes, but if your hands are covered with onion juice, this action will actually aggravate the stimulation.

Strangely, this volatile compound increases the delicious taste of onions and gives off a good smell when cooking onions. When cutting other vegetables, such as garlic, leek and leek, it will also emit sulfinic acid, but it will not form irritating sulfuric acid gas, but it will emit a strong smell.

There are many ways to solve this stimulus problem, but the effect is not the same.

The general principle is to keep your head away from onions as much as possible and let the gas almost run out before reaching your eyes. If you really can't help crying, the easiest way is to wear goggles. This method is very effective, but people around you may think you are making a mountain out of a molehill.

Besides, if the kitchen is full of steam, you may not be able to see your movements clearly (never use this method when you are using a knife). Peel the onion and put it in the refrigerator before cutting it. Because of the change of temperature, the compounds in onions will change, thus minimizing volatile gases. Similarly, you can also cook onions before cutting them to achieve this effect. Another simple method is to cut onions in water, or cut onions while washing with tap water.

It is said that if your mouth contains lemon, bread or candy, the gas will be absorbed by these foods before reaching your eyes. Breathing through the mouth instead of the nose may also help. You will inhale the gas and blow it away when you exhale. So most of the gas can't reach the eyes at all.

The method of prevention is:

1. Before cutting onions, soak the kitchen knife in cold water for a while, so that you won't shed tears when cutting again.

After cutting the onion in half, soak it in cold water before cutting it, so that you won't cry.

Put a little in the microwave oven, and the skin will be fine, and you won't cry when you cut it.

4. Before cutting the onion, soak the onion in hot water for 3 minutes.

5. Wear goggles and cut onions.

6. Hold your breath. Because the smell of onions is transmitted to the brain through the nose, it will make eyes cry.

7. The smell of onions irritates the eyes through the nose. So just stick a tissue in your nose and cut it open, and you'll be fine.

8. When cutting onions, you can light candles next to the chopping board to reduce the pungent smell of onions. The effect is good!

9. If you are already in tears, you can open the freezer of the refrigerator and stick your head in it for a while (as long as you feel a little cold on your face), so that your eyes will not flow!