Toona sinensis, Houttuynia cordata, and Durian, which one has the top 1 stink?

Audit expert: Shi Jun

Doctor of Botany, well-known popular science writer

There are always some foods that people have very different attitudes towards, either "love it very much" or "hate it very much". The controversy about their taste and smell on the Internet is also a long-standing topic. What these foods have in common is that they all have a special smell.

The Houttuynia cordata from Yunnan, Guizhou, Sichuan and Chongqing, the Chinese toon from Jiangsu and Zhejiang, and the durian from the tropics are the most controversial "three musketeers of smell".

In the "International Odor Scale" ranked by netizens, Houttuynia cordata (Houttuynia cordata) and durian are ranked first and second respectively. Toona sinensis, which is said to be limited to the season and expensive, is complained by some people for having a musty smell. But in the eyes of fans, their fragrance is refreshing and directly awakens appetite. So, where do the special smells of toona sinensis, Houttuynia cordata, and durian come from?

Seasonal specialty dish - Chinese toon

Every spring, many southerners have a seasonal dish on their tables - Chinese toon. The Chinese toon we eat is actually the young shoots of the Chinese toon plant (Toona sinensis). As a food ingredient, Chinese toon is very popular and has even been in the news due to its shortage and rising prices.

Source of Chinese toon丨TuChong Creative

(The picture has been copyrighted, and the picture content is not authorized for reproduction)

Anyone who has seen or tasted Chinese toon will be impressed by its special smell. In fact, this smell comes from the volatiles contained in Chinese toon. These special volatiles include sesquiterpenes, terpenes and other substances, which are a hodgepodge of odor components such as clove ene, caryophyllene, and camphor. Especially caryophyllene, it has a multi-flavor buff, a blend of camphor, cloves, and citrus.

Source of Chinese toon tree: Xinhuanet

No. 1 in the stinky smell list - Houttuynia cordata

The even more "amazing" flavor of Houttuynia cordata is the whole herb of the perennial herb Houttuynia cordata. Every summer and autumn, it becomes a rural flavor sought by people in the fields. The best time to harvest Houttuynia cordata is when the stems and leaves are lush and the flower spikes are numerous. Remove impurities and residual roots, wash, and then cook or dry for later use. It is a very popular wild vegetable.

Source of Houttuynia cordata丨TuChong Creative

(The picture has been copyrighted, and the picture content is not authorized for reproduction)

Modern research has also given an answer to its special smell. Through the analysis of the main chemical components of Houttuynia cordata, it contains volatile oils, flavonoids, organic acids, alkaloids and vitamins, among which volatile oils and flavonoids are its main components. Quinoyl acetaldehyde (i.e. houttuynia cordata) in the volatile oil is the reason for its fishy smell.

Internet celebrity fruit - Durian

As for the internet-famous fruit durian (Durio zibethinus), its smell has always been loved and hated by people. Research results show that the "culprit" of durian's smell is volatile sulfide. This substance has always been notorious and is often described as onion smell, rotten egg smell, rancid smell, sulfur smell, etc.

While studying durian, researchers found that a group of genes related to volatile sulfides are highly active when durian ripens, and under their influence, the durian fruit emits a strong smell.

These genes are not only found in durian, but also in common plant genomes, but only in single or double copies. Analysis of the durian genome revealed that it contains four copies. Compared with common plants, durian fruit has a higher level of volatile sulfides, which also increases the power of durian's smell. Some people think that durian smells very good, which is because the durian peel is rich in esters, which gives durian an attractive fruity aroma.

Source: Xinhuanet

How to eat toon?

The human sense of smell is amazing. Humans mainly rely on more than 400 olfactory receptors to perceive odors, but any two individuals have differences in their sense of smell. About 30% of the olfactory receptors are different, and the ability to receive odors is also different. This is why people often have a two-level evaluation of this type of food.

Although the taste of these foods is not as popular as ordinary aromas, they still have a lot of fans. For example, some people particularly like the taste of Chinese toon. The large amount of amino acids contained in Chinese toon gives it a unique flavor. Data shows that the content of glutamic acid in Chinese toon accounts for 2.6% of the dry matter of Chinese toon. The most common way people cook Chinese toon is scrambled eggs, which also hides the delicious code behind it. The substances in eggs meet the amino acids in Chinese toon, which will definitely bring a strange collision to the taste buds.

Source of Chinese toon fried eggs丨TuChong Creative

(The picture has been copyrighted, and the picture content is not authorized for reproduction)

In addition to its love-hate taste, there are also some rumors about Chinese toon on the Internet, some saying that "eating Chinese toon can cause nitrite poisoning" and "eating Chinese toon may cause cancer." Experts have also given scientific explanations for such claims.

According to toxicological analysis, nitrites do have certain acute toxicity, but it is obviously unscientific to talk about toxicity without considering the dosage. For rodents, the median lethal dose of nitrite is 57 mg/kg. Unless the human body directly consumes nitrite, it will not be poisoned. Therefore, although Chinese toon contains nitrates and nitrites, it does not mean that it will be poisoned. Similarly, although under acidic conditions, nitrites react with protein decomposition products to easily produce carcinogenic substances such as nitrosamines. However, when eating Chinese toon, blanching it in boiling water can remove most of the nitrite.

In fact, behind the strange taste is the collision of various chemical substances and the difference in human perception. When you come across these foods next time, will you love or hate them?