Have you ever taken a bite of tuna and been hit with a strange metallic taste?
It’s not just your taste buds playing tricks on you. This phenomenon is known as scombroid or histamine fish poisoning, and it can occur when dark meat fish like tuna, mackerel, bonito, and mahi-mahi are improperly handled.
But why does this happen? And what can you do to avoid it?
In this article, we’ll explore the science behind why tuna can taste like metal and provide tips for ensuring that your seafood is safe to eat.
So grab a can of tuna (or your favorite seafood dish) and let’s dive in!
Why Does Tuna Taste Like Metal?
The metallic taste in tuna is caused by histamine poisoning, which occurs when bacteria convert the amino acid histidine found in the fish muscle into histamine. This process can be controlled by storing fish on ice, but if the fish is not kept sufficiently cold, the bacteria will grow and convert the histidine to histamine.
Tuna is particularly susceptible to histamine poisoning because its body temperature is warmer than other fish, and it needs to be kept colder. Tuna burgers also create problems because meat from the belly of the fish is often used to prepare them. The belly is near the tuna’s gut, where bacteria live, and if the meat is not kept sufficiently cold, the bacteria will grow and convert the histidine to histamine.
Cooking tuna does not eliminate the histamine, so it’s important to ensure that your seafood is properly handled and stored before cooking or consuming it.
What Is Scombroid Fish Poisoning?
Scombroid fish poisoning is a type of food poisoning that occurs when people consume fish contaminated with high levels of histamines. Histamine contaminated fish often have a metallic, sharp, or peppery taste, smell bad, or have a “honey-combed” appearance. However, some contaminated fish will look, smell, and taste normal. The symptoms of scombroid poisoning usually begin within 2 minutes to several hours after eating the fish.
The most common symptoms of scombroid poisoning include tingling and burning sensations around the mouth, facial flushing, sweating, nausea, vomiting, headache, palpitations, dizziness, and rash. In some cases, people may report that the fish has a peppery or metallic taste.
Scombroid poisoning occurs when people eat fish that were not properly stored. The appearance and taste of the fish is usually normal and cooking or freezing the fish cannot prevent scombroid. Scombroid poisoning can be scary and uncomfortable, but most people recover with simple treatment.
It is important to note that scombroid poisoning is not a true allergy to a particular fish. Instead, it happens when bacteria break down the histidine in fish and turn it into histamine. When people consume large quantities of fish with histamine, they experience symptoms that resemble an allergic reaction.
To prevent scombroid poisoning, it is important to properly store and handle seafood before cooking or consuming it. This involves keeping seafood on ice at all times and ensuring that it is not left out at room temperature for extended periods of time. By taking these precautions, individuals can enjoy their seafood without the risk of scombroid poisoning.
Why Does Dark Meat Fish Cause Scombroid Poisoning?
Scombroid poisoning is a type of food poisoning caused by the ingestion of decomposing scombroid fish, such as kahawai, mackerel, tuna, bonito, and butterfly kingfish. These fish have dark meat and contain high levels of free histidine in their muscle tissues. When these fish are not properly stored, bacteria can metabolize the histidine and produce histamine, which accumulates in the fish muscle. This histamine is not destroyed by cooking or freezing, so it can still cause scombroid poisoning even if the fish has been cooked.
Certain bacteria, such as Proteus, Klebsiella, Aerobacter, and Escherichia coli, produce histamine and histamine-like substances that cause the symptoms of scombroid poisoning. The symptoms include tingling and burning sensations around the mouth, facial flushing, sweating, nausea, vomiting, headache, palpitations, dizziness, and rash. Sometimes people report that the fish has a peppery or metallic taste.
Dark meat fish are more susceptible to scombroid poisoning because they contain higher levels of histidine than white meat fish. Additionally, dark meat fish tend to be larger and have thicker muscle tissue than white meat fish, which makes it more difficult to cool them down quickly enough to prevent bacterial growth.
To prevent scombroid poisoning from dark meat fish, it’s important to ensure that the fish is properly stored on ice or refrigerated at temperatures below 40°F (4°C). It’s also important to purchase fish from reputable sources and to avoid eating fish that has been sitting out at room temperature for an extended period of time. If you suspect that you may have scombroid poisoning from eating dark meat fish, seek medical attention immediately.
How Does Scombroid Poisoning Affect Taste?
Scombroid poisoning can affect the taste of fish in various ways. The contaminated fish may have a metallic, sharp, or peppery taste, or it may smell bad. However, some contaminated fish may look, smell, and taste normal.
The reason for this strange taste is due to the high levels of histamines in the fish. Histamine is a chemical that is produced by bacteria when fish is not properly stored. When ingested, histamine can cause tingling and burning sensations around the mouth, facial flushing, sweating, nausea, vomiting, headache, palpitations, dizziness, and rash.
It’s important to note that scombroid poisoning does not affect everyone who ingests it. Additionally, cooking or freezing the fish cannot prevent scombroid poisoning because the toxins remain in the tissues and can be absorbed after the food is ingested.
Therefore, it’s crucial to ensure that fish is properly stored and handled to prevent scombroid poisoning and any unpleasant taste that may come with it.
Other Symptoms Of Scombroid Poisoning To Watch Out For
Scombroid poisoning is a type of food poisoning that can occur when certain types of fish are not stored properly. Along with the symptoms mentioned above, there are other symptoms to watch out for if you suspect you may have scombroid poisoning.
One symptom to look out for is difficulty breathing. If you experience shortness of breath, wheezing, or chest tightness after consuming fish, seek medical attention immediately. Swelling of the tongue and mouth can also occur, which can make it difficult to breathe or swallow.
In severe cases, scombroid poisoning can cause anaphylaxis, a life-threatening allergic reaction that requires immediate medical attention. Symptoms of anaphylaxis include hives, swelling of the face and throat, rapid heartbeat, and low blood pressure.
If you suspect that you or someone you know may have scombroid poisoning, it’s important to seek medical attention right away. Treatment may include antihistamines or other medications to relieve symptoms and prevent complications such as dehydration.
To prevent scombroid poisoning, it’s important to ensure that fish is stored at the proper temperature (no higher than 40 degrees Fahrenheit) from the time it is caught until the time it is consumed. If you’re unsure about the quality or freshness of fish, it’s best to err on the side of caution and avoid consuming it.
How To Properly Handle And Store Dark Meat Fish
If you’re handling and storing dark meat fish like tuna, it’s important to follow some basic guidelines to ensure that you don’t get sick from histamine poisoning. Here are some tips for proper handling and storage:
1. Store in a cool, dry place: Keep your canned tuna in a cool, clean, dry place where temperatures are below 85 F (between 50-70 F is good) but not freezing temperatures. This will help prevent the growth of bacteria that can convert histidine to histamine.
2. Rotate your stock: Make sure to rotate your canned foods so that the oldest is used first. Try not to keep canned foods more than 1 year.
3. Check expiration dates: Use canned meats and seafood within 3 years of the date on the package. Use low-acid canned foods like vegetables and soup within 3 years of the date on the package. Use high-acid foods like fruit, pickles and tomatoes within 2 years of the date on the package. Canned fruit juices can be stored up to 1 year.
4. Look for signs of spoilage or damage: Foods stored longer will be safe to eat if the cans do not show signs of spoilage or damage, but the foods may deteriorate in color, flavor and nutritional value.
5. Don’t eat too much: While tuna is a healthy food choice, it’s important not to eat too much of it due to its high mercury content. This is especially true for pregnant women and children.
By following these simple guidelines, you can safely enjoy the fine taste and good nutrition of dark meat fish like tuna without worrying about histamine poisoning or other health risks.
Tips For Avoiding Scombroid Fish Poisoning When Eating Out
Scombroid poisoning is another type of fish poisoning that can occur when eating certain types of fish that have not been stored properly. The symptoms of scombroid poisoning can be scary and uncomfortable, but simple treatment can help most people recover. To avoid scombroid poisoning when eating out, here are some tips to keep in mind:
1. Avoid certain types of fish: Some types of fish are more likely to carry the bacteria that cause scombroid poisoning. These include tuna, mackerel, mahi-mahi, sardines, anchovies, herring, bluefish, amberjack, and marlin. If you’re not sure what type of fish is being served, ask the server or chef.
2. Check the freshness: Fresh fish should have a mild ocean scent and firm flesh. If the fish smells overly fishy or has soft or discolored flesh, it may not be fresh and could be more likely to cause scombroid poisoning.
3. Look for signs of proper storage: Fish that has been properly stored should be kept on ice or refrigerated at a temperature below 40°F (4°C). If you notice that the fish is not being stored properly, it’s best to avoid it.
4. Be cautious with tuna: As mentioned earlier, tuna is particularly susceptible to histamine poisoning and scombroid poisoning. When ordering tuna at a restaurant, ask how it has been stored and cooked.
5. Trust your instincts: If something doesn’t seem right about the fish you’re about to eat, it’s better to err on the side of caution and avoid it.
By following these tips, you can reduce your risk of scombroid poisoning when eating out and enjoy your seafood without any unpleasant side effects.
