Jellyfish are poisonous, so why are sea cucumbers edible?

I often see netizens say "Most jellyfish are poisonous, so why can sea cucumbers be eaten? Is it a problem with the species or has the toxicity been eliminated?" I have to say, this is a good question. A similar question can be extended to: why are snakes poisonous, but snake meat can be eaten?

In fact, to put it bluntly, the core reason why poisonous meat can be eaten is the poison. Today, let's talk about the issue of "poison".

01. The poison we imagine

Generally speaking, when we talk about poison, we often think of some poisons, such as arsenic trioxide, paraquat, which has serious sequelae and can lead to death if not treated in time, etc. The characteristics of these poisons are that their core components are some inorganic molecules or organic molecules with stable structures. These molecules are relatively stable, so they will retain their toxicity whether they are heated or not or treated in general . This is why some people will be poisoned after eating vegetables sprayed with pesticides.

However, biological poisons are different from this.

02. Biological poison

What are biological toxins? For example, jellyfish poison, centipede poison or snake poison. These toxins are different from the general poisons mentioned above. The core components of these toxins are proteins (or some polypeptides). As we all know, proteins are organic substances that are necessary for the human body. Of course, the human body can also synthesize these organic substances.

Led by researchers Zhang Yun and Li Wenhui, the Biotoxins and Human Diseases Research Group of the Key Laboratory of Animal Models and Human Disease Mechanisms of the Kunming Institute of Zoology, Chinese Academy of Sciences, used advanced modern biochemistry and molecular biology research techniques and methods to conduct the most comprehensive and systematic revelation of the pharmacological molecular groups and pharmacological activities of centipedes to date, and newly identified more than 400 centipede peptide bioactive substances. The research group further cooperated with Ding Jiuping's research group of the Key Laboratory of Molecular Biophysics of Huazhong University of Science and Technology, revealing that many centipede peptide bioactive substances can act on different cell membrane ion channels (including sodium, potassium, calcium ion channels, etc.) to exert pharmacological effects.

In order for proteins to function, they must maintain their structure, especially their three-dimensional structure, so that they can play relevant roles (such as common catalytic reactions). However, the disadvantage of this toxin is very obvious, that is, it is too dependent on structure. They must use specific structures to bind and catalyze, and then they can play a stable role. Once these structures are destroyed, it is easy to cause the loss of toxicity.

03. How to eliminate biological toxins?

Physical factors are the most common method, typically high temperature boiling can cause protein denaturation (such as boiling eggs)

Chemical factors can be changed by adjusting the concentration, density and composition, such as the treatment of jellyfish. The common alcohol disinfection also follows this principle.

Biological factors also exist, but they are less common.

As for jellyfish, many of the current processing methods use high salt, such as pickling and inactivation with high concentrations of alum and salt. These factors combined will cause the protein to denature, and then it can be eaten.