According to a report on the BBC website on May 28, this is what happened. Chinese media reported not long ago that the Longyangxia Reservoir in Qinghai is currently the largest salmon farm in the country, and one-third of the salmon on the market is produced here.

Afterwards, netizens started to discuss, isn’t this selling dog meat (three-text) with sheep’s heads (rainbow trout)? Some people cried and complained that they were deceived, always thinking that they were eating authentic salmon imported from Europe; others swore that they would never buy it again.

Afterwards, the China Fisheries Association and the China Fisheries and Distribution Processing Association issued statements to clarify the facts, and many science experts published articles in an attempt to clear up doubts.

However, the online controversy has not yet subsided. What most “foodies” are most concerned about is food safety. They worry that freshwater rainbow trout contain parasites and are dangerous to eat raw.

Watch out for parasites?

Rainbow trout and salmon, let’s not discuss the blood relationship from an academic perspective, but from the perspective of nutritional content, they are actually very beneficial to health.

However, even the so-called "orthodox" salmon are not suitable for eating raw: salmon grown in the sea are not necessarily parasite-free, and freshwater cultured salmon - whether it is called rainbow trout or salmon - It doesn't necessarily mean there are parasites.

The UK’s “health expert”, the National Health Service, has issued a safety warning to fishing enthusiasts who insist on eating their own “prey”.

The warning begins by stating that salmon and sea trout caught from the Atlantic or British rivers are at risk of containing parasites, including larvae and anisakis.

Parasites in fish, especially Anisakis larvae, if eaten raw, can cause abdominal pain, diarrhea, vomiting, blood in the stool, mild fever and other symptoms, and may also cause allergic reactions, including rashes , itchy skin, and even anaphylactic shock.

How to eat it?

How to eat safely? The UK's "quality control experts", the British Food Standards Agency, have the following advice.

Clean up: Anisakis larvae may adhere to the surface of tissue around fish guts and intestines. Clean the internal organs, carefully inspect the abdominal cavity and muscles of the fish, and remove any parasites visible to the naked eye. In most cases, especially in salmon, the parasites may also hide inside the muscles, especially those around the abdominal cavity and excretory openings. Carefully examine the muscles surrounding the excretory opening. Those fish that excrete red and swollen lips should be especially careful.

Freeze before eating: If wild fish is to be eaten raw or semi-raw, make sure that all parts, especially the thicker parts, are refrigerated at minus 15 degrees Celsius (or lower) for at least 4 sky. Doing this will kill all the Anisakis larvae. If you want to freeze very large whole fish or very large pieces of fish, it may take longer for the inside of the fish to achieve the ideal freezing effect. A minimum of 5 days is recommended, making sure all parts are refrigerated at a sufficiently low temperature for at least 4 full days. This also applies to fish that is smoked, salted or seasoned and eaten raw.

Eat cooked: Smoked wild salmon or rainbow trout, make sure the thickest part of the meat exceeds 60 degrees Celsius for at least one minute to ensure that all Anisakis larvae are killed. If it cannot be frozen properly or other cooking methods are used, make sure it is cooked through and the fish should be "steaming hot" in the middle. If you are not sure, you can use a cooking thermometer inserted into the center of the fish to test it. Although heating the fish meat to more than 60 degrees for at least one minute is enough to kill the larvae of Anisakis, it is generally recommended to heat it to 70 degrees for 2 minutes to ensure that all pathogenic bacteria (including Listeria) that may be contained in the fish are eliminated. ).

The UK has strict regulations that require shops to control the parasites contained in fish products sold to a "minimum level", the report said.

The report also stated that, in addition, unless exempted from regulatory requirements, all fish products sold in stores that are eaten raw, semi-raw (such as sushi), salted, soaked in sauce and other preparation methods must be inspected. Refrigerate to kill any parasites.

However, in recent years, the incidence of nematodes has been increasing in European countries.

Doctors wrote in the British Medical Journal that this may be related to the increasing popularity of sushi. Previously, most nematode diseases occurred in Japan, which has a tradition of eating raw fish.