Why is the champion single product "leek box" so delicious~~

Audit expert: Wang Guoyi

Postdoctoral fellow in Nutrition and Food Safety, China Agricultural University

The afterglow of the Winter Olympics has not yet dissipated, and the taste of the leek dumplings that the "genius girl" Gu Ailing ate while waiting for her scores seems to be right in front of you - that's right, you don't even have to eat or see leeks, as long as you think of this food, its unique spicy smell will appear in your mind, which is one of the most recognizable smells.

As the saying goes, "Onions in January and chives in February" means that chives are best eaten in February of the lunar calendar, when the quality of chives is at its best. Chives are delicious, but the taste in your mouth after eating them is really unpleasant. So, where does the spicy smell of chives come from? What is the taste after eating chives? Let's find out today.

Where does the unpleasant smell come from? Scallions, leeks, onions, and garlic all have a unique spicy taste. Although delicious, there will be a lingering strong smell in the mouth after eating. Some people even sweat with garlic smell. Why is this?

Allium tuberosum in the wild

Source: Wikipedia

These offensive smells can be traced back to allicin.

Allicin is an organic sulfur compound. The extracted allicin is an oily liquid with a light yellow appearance.

When we cut garlic (or other allium plants), its cells are destroyed, and the unstable alliin contained in it is decomposed and reorganized under the action of alliinase to form allicin. Allicin will continue to decompose in the medium of water and oil to produce diallyl disulfide (DADS) and other substances. When we eat these ingredients, the "garlic flavor" in our mouths mainly comes from allicin and these substances that are decomposed from it.

Chemical structure of DADS

Source: Wikipedia

Of course, these unique flavor substances in allium plants are not evolved specifically for human consumption. For plants, these pungent substances can drive away animals that eat them and kill bacteria and fungi that infect tissues, which is an important means of defense.

According to biologists, organisms can sense the smell of DADS mainly through a protein ion channel called TRPA1 (transient voltage receptor cation channel, subclass A, member 1. TRPA1 is its abbreviation). This ion channel appeared very early in organisms. Not only humans and animals have this channel, but it can also be found in fungal cells. That is to say, a long time ago, allium plants began to use this spicy chemical to protect themselves.

Allicin, a spicy onion plant, is not exclusive to garlic, but also exists in various Allium subfamily plants, especially Allium plants. Allium plants were once classified as Liliaceae, or Allium was classified as an independent Allium family, but are now classified as Amaryllis family under Asparagus.

We can find many vegetables with pungent smell in the vegetable section of the supermarket, such as shallots, garlic, leeks, onions, chives, scallions, alliums, etc., all of which are Allium plants. Most of their pungent smells come from allicin. However, the flavor is affected by the allicin content and other flavor substances contained, so not all Allium plants taste like garlic.

However, due to the presence of allicin, many Allium plants will still "enchant" the mouth after being eaten: the person cannot speak, and once the mouth is opened, the odor is so strong that people around them stay away.

It is precisely because of this characteristic of allium plants that some of them were listed as the "Five Spicy Vegetables" in ancient Buddhism, and practitioners were forbidden to eat them. The Mahayana Brahma Net Sutra records that "...the five spicy vegetables are garlic, leek, chives, garlic, and leeks..." Among them, ferula does not belong to the genus Allium (it belongs to the genus Ferula of the order Apiaceae), and the other four are all allium plants that contain allicin.

garlic

Source: Wikipedia

There are also sayings that the five pungent vegetables are "garlic, shallot, leek, brassica, and coriander"; "leek, scallion, onion, garlic, and ginger" etc. In the Compendium of Materia Medica, it is recorded that the "five pungent vegetables" to be eaten at the beginning of spring include leek, scallion, onion, garlic, and ginger.

In addition, there is also a saying that garlic and other "five pungent vegetables" can induce sexual desire and therefore should be avoided.

How to make your breath fresher? How does the pungent smell of allicin turn into an unbearable odor in your mouth?

This is because after eating Allium plants such as leeks and garlic, allicin will be broken down in the stomach and converted into allyl methyl sulfide (AMS). AMS is the main source of the smell in our breath after eating leek boxes.

What’s more important is that AMS cannot be further degraded in the body and can only be excreted through exhalation, sweat, and urine. Therefore, after ingesting allium plants, even brushing your teeth and rinsing your mouth cannot completely remove the odor.

So, how can you avoid bad breath after eating onions, garlic and leeks?

Heating thoroughly: After heating, alliinase will be inactivated at high temperatures, reducing the content of allicin, which can cause bad breath. In addition, even after alliinase is inactivated, garlic still has a relatively strong antibacterial effect, so there is no need to worry that garlic will "lose its nutritional value" after heating.

Eat less: The reason is simple, the less you eat, the less AMS your body needs to excrete, the shorter the time required, and the lower the concentration (and therefore the smell).

Brush your teeth and rinse your mouth immediately: After eating food containing allicin, brush your teeth and rinse your mouth as soon as possible, and chew some chewing gum to reduce the residue of allicin and food debris in the mouth, which can relieve the odor to a certain extent.

Drink tea: Some studies have shown that tea polyphenols can react with the sulfur compounds in garlic to reduce bad breath. Drinking some tea or chewing tea leaves can also relieve bad breath.

Even though it leaves a bad taste in your mouth, who cares about the delicious food? Chive dumplings, garlic shrimps, spring onion tofu... all of them, come to my bowl!