Does Freezing Salmon Kill Parasites? (Must-Read)

Does Freezing Salmon Kill Parasites
Foods Questions

We all know that salmon is an amazing fish and a great source of omega-3 fatty acids, but it can also contain parasites.

If you are like most people, you might be wondering whether freezing will kill those parasites.

So, does freezing salmon kill parasites?

Yes, freezing can actually kill parasites. Freezing not only helps remove these harmful parasites from the fish but also reduces spoilage as well as decreases bacteria growth on the surface skin which prevents discoloration.

Parasites are found in freshwater or saltwater environments so if you’re going fishing or getting your fish from the market, you should always inspect the fish for any parasites.

How does freezing kill parasites?

Parasites are usually microscopic animals that parasitize a host organism. A parasite is not necessarily a virus or a microbe, it can also be an insect, etc…

Freezing works in two possible ways to kill these parasites:

The first one is by destroying the cells of the fish and parasites through ice crystal formation within them which freezes waters in the tissues. Once they have been frozen, their cells burst and they die.

The second process involves enzymes that are naturally present in the body of any living creature such as salmon; they slow down when exposed to freezing temperatures.

They keep on slowing down until finally becoming inactive at subzero levels, killing all forms of life including parasites.

How long do you freeze salmon to kill parasites?

To kill parasites in salmon, you freeze it for about 24 hours at a temperature of -35°C (-31.4°F).

You have to allow the fish and its internal organs to be exposed to this freezing temperature for at least 24 hours before consumption.

Try this method and enjoy your healthy meal with no worries about parasites in your salmon!

What temperature kills parasites in salmon?

The parasites in salmon can be killed at a temperature of -35°C (-31.4°F).  But the parasites can still survive in extremely cold regions during winter.

If you want to eat raw salmon, you need to ensure that it has around -35°C throughout the whole process.

When you freeze fish, the cells in its body ice up and explode before they are frozen completely. This explosion kills parasites. But this does not work on all parasites as some of them can survive cold temperatures.

These parasites include species such as Diphyllobothrium nihonkaiense (this parasite is a broad tapeworm found in Pacific salmon) which lives in freshwater riverbeds but migrates into marine waters during summer.

What are the possible risks of eating raw salmon?

Even if freezing can kill most parasites, it is not 100% safe to consume raw fish. It has been reported that some people experience nausea, vomiting, or diarrhea after eating raw or undercooked fish.

The main concern with these symptoms is the norovirus which comes from infected persons and contaminated food or water sources. The illness usually lasts from one to four days and will cause sudden vomiting as well as watery diarrhea.

To prevent yourself from this virus (or any other food-borne pathogen), try cooking your fish before consumption!

Does cooking kill all parasites in salmon?

Cooking salmon will kill any parasites that are in the fish.

In addition, cooking salmon will also kill some harmful microorganisms like bacteria present on its surface and skin which cause food poisoning if not removed before consumption.

Some people prevent themselves from having parasites by filtering water or using a water purification system before having fresh raw seafood (especially shellfish) but this method is not yet 100% effective against all possible risks.

The best way to decrease your chances of getting sick from eating raw salmon is by making sure it has been thoroughly cooked.

Does cooking or freezing affect the taste of salmon?

Freezing and cooking both do change the taste of fish significantly. Freezing can remove the strong smell from raw fish but it will take away some other features as well. 

Cooking is a better option if you want your food to taste good!

Does freezing salmon kill worms?

Freezing does kill worms in salmon. The parasites are killed by the freezing temperatures before they can start reproducing and infecting you with their eggs.

However, it is not 100% effective against all species of worms. Freezing can only kill those parasites that depend entirely on marine water for survival such as Diphyllobothrium nihonkaiense.

There is a parasite called broad tapeworm which has adapted to freshwater because of its ability to migrate into freshwater during summer.

It has been reported that this parasite has survived freezing in freshwater even though there was ice formation present inside its body cells.

How long do you freeze salmon to kill worms? 

Salmon should be frozen for up to 24 hours to kill worms.

Does freezing raw salmon kill any viruses? 

Freezing can be used to prevent you from getting noroviruses but this is not the only food-borne pathogen that could make you sick. 

There are many other types of viruses that can be present in seafood and it takes a slightly longer time than 24 hours to eliminate them completely.

Some research has shown that freezing for 3 days was not effective enough in removing Listeria monocytogenes (a bacterium) from cold-water fish such as cod, haddock, and hake.

This means that even if your salmon is frozen well, there may still be some microorganisms present on its surface which can lead to food poisoning.

Does freezing fresh salmon kill any other parasites? 

Any non-freezable parasites will be killed by the freezing temperature, however, if the fish was not frozen for long enough this parasite could start reproducing and infect you with its eggs.

The most common symptoms of infection with these worms are nausea (feeling sick), vomiting, or diarrhea if they were present in your stomach while defrosting.   So it is better to cook your salmon to make sure there are no more parasites!

Final Thoughts

Freezing salmon kills parasites. However, freezing does not kill all the bacteria that could potentially contaminate your meat so it is important to cook any frozen fish thoroughly before eating.

The FDA recommends cooking frozen seafood until an internal temperature of 145 degrees Fahrenheit (63 degrees Celsius) has been reached in order to prevent food poisoning from harmful bacteria such as ileal, salmonella, and listeria monocytogenes.

To make sure you are following these recommendations for safety purposes, I recommend using a digital thermometer with a probe or instant-read function when checking the internal temperature of cooked food products like steaks or roasts.

You can also use this thermometer during the cooking process if desired by inserting it into the thickest part of the fish.

Reference

USDA: Food Safety and Inspection Service