If there is a sound, it must be the sound coming from the stomach of the foodie. After staying at home for more than two months, I think the foodies have already rubbed their fists and are ready to eat a big meal when the epidemic is over!
Seafood grilled crayfish, I want to kill you!
Speaking of which, tears flowed from the corners of his mouth
Blue Goose... The upcoming months of April and June are not a good time to eat seafood – seafood poisoning incidents occur frequently during this time of year. If you are unfortunate enough to eat poisonous seafood, the days of "squatting at home" will be extended again.
So how to avoid eating poisonous seafood? Let's start with the seafood toxins themselves. Common seafood toxins can be simply divided into two categories: fish toxins and shellfish toxins.
Fish, shrimp and crab shellfish provide 13.8% to 16.5% of the protein source for humans and are an important part of the human diet. However, tens of thousands of people are poisoned by eating seafood every year, and the main source of poison is the various toxins that may be contained in the seafood
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Fish toxins
Tetrodotoxin
The most famous of the fish toxins is Tetrodotoxin, and there are not a few people who eat pufferfish poisoning every year.
Tetrodotoxin usually accumulates in the blood, ovaries (eggs) and liver of the pufferfish. However, the toxic parts of different species of pufferfish and the mechanism of toxin production are different, some species of pufferfish are almost non-toxic (such as sphoeroides maculatus); while some species of pufferfish, eyes, skin, sperm nest and even muscles are poisonous.
Spotted Pufferfish 丨 Smithsonian Environmental Research Center / Wikimedia
Tetrodotoxin is an extremely strong neurotoxin, how strong is it, only 1 to 2 mg is enough to cause death, and there is currently no antidote. Therefore, if you want to eat delicious puffer fish meat, you must have a professional chef remove the poisonous parts such as eyes, kidneys and blood.
In Japan, restaurants selling puffer fish are heavily regulated, and only chefs with more than three years of professional training can cook puffer fish. Poisoning incidents often occur in informal restaurants or when people cook at home.
Japanese puffer fish sashimi
The prevailing view is that tetrodotoxin is actually produced by bacteria. These tetrodotoxin-producing bacteria are widely distributed in seawater and organisms, including Actinomycetes, Vibrio, and Pseudomonas. In the process of feeding, puffer fish accumulate these bacteria and the fudodotoxin they produce little by little in the body through the enrichment of the food chain, and finally cultivate themselves into a swimming fish-type poisoner.
But now we don't have to risk death to eat pufferfish. In the process of breeding puffer fish, people can greatly reduce the concentration of toxins in the body of puffer fish through strict water source control and feed control, so that artificially farmed puffer fish can maintain a low or even non-toxic level.
Since 2016, China has opened up the cultivation of dark-striped oriental pufferfish and redfin oriental pufferfish, and these two kinds of farmed puffer fish sold in the regular market can be eaten with confidence.
Comparison chart of different species of puffer fish, where A. Dark-striped Oriental Pufferfish;B. Redfin Eastern Pufferfish;C. Star-spotted Oriental Pufferfish;D. Leopard-striped multigeoners;E. Spotted polycephalus;F. Purple multi-era pufferfish.
Ciguatera toxin
Tetrodotoxin is deadly, but its impact is not yet the greatest. Among fish toxins, the largest number of cases of poisoning occur each year in Ciguatera. The U.S. Centers for Disease Control estimates that about 50,000 people worldwide are poisoned with ciguatera toxin each year.
Ciguatera toxin is produced by certain marine algae that grow in tropical and subtropical regions. Similar to tetrodotoxin, it is also enriched through the food chain into large reef fish.
Ciguatera toxin is mainly concentrated in the head, skin and internal organs of fish. In general, the larger the fish, the higher the toxin content.
The large grouper in the coral reef, pictured as brown-spotted grouper, also known as tiger spotted
Ciguatera poisoning occurs mostly in the Pacific, Indian and Caribbean Seas between 35° north and 35° south. However, due to the deterioration of coral reefs and the increase in seafood trade, this risk may spread around the world, so it is best not to eat large fish from the reef waters, such as Su mei (corrugated lip fish Cheilinus undulatus), tiger spot (brown spotted grouper Epinephelus fuscoguttatus) and Eastern Star Spot (leopard gillthorn Plectropomus leopardus).
Corrugated lip fish
Leopard-striped gill perch
Unlike the above two types of toxins, there is another toxin that is not in the fish itself, but is produced by improper preservation after the fish has been caught by humans. For example, there are nearly 100 species of fish such as mackerel suborder "green skin red meat fish" (including mackerel, tuna, marlin), mackerel, sardines and so on.
Fat-rich mackerel (mackerel) can easily spoil if not properly preserved. But frying it in oil is really delicious!
Their flesh contains a large amount of histidine, and when they are stored in a high-temperature environment for a long time, bacteria in the body multiply in large quantities, converting histidine into toxic histamine (Histamine). In 2004, there was an incident of collective histamine poisoning in 188 people in Huli District, Xiamen, due to the consumption of spoiled saury.
Therefore, when buying seafood, it is important to ensure that it is fresh enough and pay attention to whether the storage conditions are appropriate (from being caught to cooking, it needs to be kept at low temperatures), and it is even more important to pay attention to the upcoming summer.
Tips for picking sea fish:
Fresh marine fish have a mild odor and no strong fishy smell; the fish eyes are clear and shiny, not sunken; and the gills are moist and pale red or dark red.
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Shellfish toxins
After talking about fish, let's talk about shellfish. Shellfish here refer to species of mollusk phylum bivalves (shellfish) and gastropods (snails).
Charcoal grilled clams or something
The vast majority of bivalves live a filter-fed life, and there is something in the water that it eats. If there are a lot of toxic algae in the water, they will inevitably accumulate algal toxins in their bodies. Therefore, what we call "shellfish poison" should be "algal poison" to be precise.
This also explains why shellfish toxins are not unique to shellfish: some starfish and crabs also have shellfish toxins in them.
In the sea where the red tide of algae erupts, the number of toxic algae in the water body surges, resulting in the death of a large number of organisms, and the algal poison is also stored in some "dead" organisms through the food chain. Unfortunately, before these creatures could expel the toxins from their bodies, they became the food on the plate of diners, and finally fell on the charge of "poison", thinking that they felt wronged for them.
Red tide is a harmful ecological phenomenon caused by the explosive proliferation or high concentration of some tiny plankton in seawater under specific environmental conditions. In addition, marine pollution and other reasons, will also cause local shellfish to carry toxins or pathogens, you can poke here to see.
Compared with bivalves, gastropods have a tooth-like tooth-like tongue structure and can actively feed, and they are much less likely to contain shellfish venom in their bodies. But there are individual species, such as the famous weave snail, which is still at risk of poisoning because the recipe contains toxic algae.
The weaved snail refers to a type of snail in the family woven snail family. The picture shows the species of snails in the southeast coast of China and their toxicity.
Shellfish toxins generally accumulate in the gills, gonads, digestive glands and other internal organs of shellfish, and the foot content is low. Shellfish toxins include four main categories: paralytic shellfish toxin, diarrheal shellfish toxin, neurologic shellfish toxin and forgetful shellfish toxin. Among them, paralytic shellfish poison is the most widely distributed and harmful class of toxins in the world.
At present, the mainstream view in China is that the main components of toxic spirochrotoxin are tetrodotoxin and paralytic shellfish poison.
The main type of seafood poisoning caused by algal toxins
Some friends will feel that even if there are thousands of seafood toxins, is it okay to cook and then eat? Unfortunately, all of the toxins mentioned above are highly heat-resistant and cannot be removed by conventional cooking methods.
However, thorough cooking can indeed greatly eliminate the hidden dangers of parasites and germs attached to seafood. For example, 90% of wild marine fish contain isoscephalia, as well as the most common Vibrio parahaemolyticis in seafood, can be completely killed in boiling water for a few minutes, so it is still necessary to cook thoroughly.
There are strict standards for raw aquatic products, but seafood in addition to this is thoroughly cooked before eating
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It is also impossible to prevent
In addition to the above-mentioned fish toxins and shellfish toxins, known toxins in seafood include abalone toxins in abalone internal organs, tetramethylammonium hydroxide salts in the salivary glands of moth snails, and so on.
You may be shocked to see here, there are so many kinds of "poison" in seafood, isn't it invincible? Don't worry, now that there is strict market control over common poisonous seafood, as an ordinary foodie, you only need to do the following points to not worry too much about seafood poisoning:
1. Buy from a regular mall. Large supermarkets or seafood markets have better purchase channels and inspection mechanisms, which can help you eliminate most of the "thunder".
2. Avoid spoiled seafood. Eat only fresh or well-preserved seafood, as spoiled seafood may contain a lot of histamine, which can lead to poisoning.
3. Cook thoroughly. Although seafood toxins are resistant to high temperatures, parasites and germs attached to seafood can be effectively destroyed by high temperatures.
4. Consume in moderation. Don't eat too much seafood at once and keep the risk under control.
5. It is best to avoid eating offal parts. Most of the toxins in seafood are concentrated in the internal organs, and the muscles are safer.
If you are not at ease, you can also learn to identify common poisonous seafood (such as textured snails, fan crabs, etc.); keep abreast of the red tide dynamics from the Internet, and actively avoid seafood from the red tide sea. The more you know about it, the safer it will be for you.
Toxins in members of the family Fan Crab do not disappear even after heating, and these toxins may be produced by bacteria that symbiosis with crabs. Occasionally, in the seafood market, there will be fan crabs that are accidentally mixed into other edible seafood, and if they are not carefully eaten, they will cause poisoning
Taiwan's report on accidentally buying a poisonous fan crab. Chinese the oddly named Zosimus aeneus and the upright crab Atergatis integerrimus, both members of the family Scallopidae.
Finally, since the symptoms of various types of seafood poisoning are similar, and may even be similar to the symptoms of seafood allergies, please do not use folk methods to treat it when you cannot determine the cause. If you feel obvious discomfort after eating seafood, be sure to seek medical attention in time!
Talking about it, my grilled seafood arrived!