Tuna: Pan-Seared Safety

Pan-seared tuna is a popular dish, but is it safe to eat? The answer is a little complicated. Firstly, it's important to note that sushi-grade is a marketing term and does not guarantee safety. The safest option is to buy tuna that has been graded by wholesalers; Grade 1 tuna is most likely what is considered sushi-grade. Flash-freezing tuna within a couple of hours of being caught is also a common practice to ensure safety. When cooking, it is recommended to sear the tuna very quickly over high heat, leaving the inside raw. However, it's important to remember that consuming raw fish always carries some risk, and one should only purchase tuna from reputable sellers and consume it on the same day as buying it to minimise this risk.

Parasites in raw fish

Consuming raw or undercooked fish can lead to parasitic infections. One such parasite is the fish tapeworm, or Diphyllobothrium spp, which can be acquired by eating raw or undercooked freshwater or anadromous fish (sea fish that spawn in freshwater rivers, such as salmon). Marinated and smoked fish can also transmit this parasite. While cases have decreased in previously endemic areas due to improved sewage treatment, they have increased in other parts of the developed world, likely due to the increased consumption of raw fish.

Another parasite is Anisakis simplex, a parasitic nematode (roundworm) that can cause anisakiasis in humans who consume raw or undercooked fish. This parasite is frequently found in cod, haddock, fluke, Pacific salmon, herring, flounder, and monkfish. Symptoms of anisakiasis include violent abdominal pain, nausea, and vomiting. In some cases, the worm may be coughed up or vomited out, but if it penetrates the intestinal tissues, it can cause a severe immune response similar to appendicitis or Crohn's disease.

To prevent parasitic infections, it is important to properly cook fish to a temperature of 130°F (54.4°C) for five minutes or freeze it below 14°F (-10.0°C). The Food and Drug Administration (FDA) has provided guidelines for retailers selling fish intended to be eaten raw, including freezing the fish to -31°F for 15 hours or -4°F for 7 days to kill parasites. Additionally, proper food safety practices, such as washing hands and avoiding cross-contamination, are crucial.

When consuming raw or undercooked fish, it is important to be aware of the risks associated with parasitic infections. While these infections are rare, they can have serious health consequences. It is always advisable to cook fish thoroughly to reduce the risk of parasitic infections.

Tuna grades

Tuna is graded based on several factors that determine the quality and value of the fish. The criteria used for grading are colour, fat content, size, freshness, and overall appearance. The fish's condition, texture, smell, and absence of physical defects like bruises or discolouration are carefully assessed to determine its grade.

Colour

The colour of tuna can range from light pink to deep red, with a vibrant and consistent hue indicating higher quality. The colour's brightness, intensity, and even distribution throughout the flesh are considered during grading.

Fat Content

Fat content in tuna contributes to its flavour, texture, and moisture levels. Tuna grades are often classified by their fat content as either lean or fatty. Lean cuts have less visible marbling and lower fat content, resulting in a firmer texture. Fatty cuts, on the other hand, contain more intramuscular fat, which gives them a smoother texture, rich taste, and buttery mouthfeel.

Other Factors

In addition to colour and fat content, other factors such as size, freshness, and overall appearance also play a role in grading. Larger fish tend to have more desirable meat. Freshness is also key, as the most recently caught fish are usually of better quality.

Tuna Grading Chart

A tuna grading chart can vary slightly depending on the region or market. Here are some common grades:

• #1 Grade: This is typically the highest grade available for tuna. It represents superior quality with vibrant coloration, high fat content, exceptional flavour, and a buttery texture. #1 tuna is best treated simply, either raw or rare, in dishes like poke, tartare, or quickly seared.
• #2 Grade: This grade falls slightly below #1 but still maintains good colour and flavour. However, it may have less fat marbling or a slightly less desirable texture. #2 tuna is mild and firmer in texture. It can be seared, poached, grilled, or roasted but should be cooked carefully to avoid overcooking, which can make it tough and dry.
• #2+ Grade: This grade exhibits fat content but is generally leaner than #1. The texture is wet and smooth but not as sticky. The colour is still bright and clear but not as even as #1. This grade is suitable for raw dishes like sushi and sashimi.
• #3 Grade: This grade is more opaque and is considered "grill grade". It can have a bitter taste if eaten raw, so it is best suited for grilling.
• Sushi/Sashimi Grade: This grade is specifically labelled for raw consumption due to its freshness and careful handling.
• Canning/Loins Grade: This grade is intended for canning or processing into loins. While still of decent quality, it may not exhibit the same attributes as higher-grade options when consumed.

Marinating tuna

There are many different ingredients you can use to make a delicious marinade for tuna. Here are some ideas for two different marinades:

Marinade 1:

• Olive oil
• Honey
• Minced garlic
• Cilantro
• Parsley
• Salt and coarsely cracked black pepper
• Cumin
• Smoked paprika
• Lemon juice

Marinade 2:

• Soy sauce
• Sesame oil
• Sriracha
• Garlic
• Ginger
• Green onions
• Lime
• Pepper

To make the marinade, simply combine all the ingredients and whisk vigorously. Then, place your tuna steaks in a gallon Ziploc bag and pour in the marinade, tossing to coat the tuna. Press out any excess air and seal the bag. Place the bag in the fridge and leave to chill for 30 minutes to 2 hours.

When you're ready to cook your tuna steaks, remove them from the marinade and shake off any excess. You can then grill them, sear them in a skillet, or broil them in the oven. Only cook the tuna until it is easily flaked with a fork and the centre is just barely pink—this will ensure your tuna steaks are juicy and tender.

Tuna cooking times

Tuna steaks are best served rare or medium-rare. This means that the outside of the tuna steak will be seared, while the inside remains raw.

The cooking time for tuna steaks depends on the desired level of doneness and the thickness of the steak. Here is a general guide for cooking tuna steaks:

Pan-Searing Tuna Steaks

• For a 1-inch thick tuna steak, sear each side for about 1 to 1.5 minutes for rare, 2 to 2.5 minutes for medium-rare, and up to 3 minutes for medium-well to well-done.
• For thinner steaks (less than 1 inch), reduce the cooking time to no more than 1 minute per side for rare.
• For thicker steaks (1.5 inches or thicker), increase the cooking time to 2 minutes per side for medium-rare.
• Always preheat your pan over medium to medium-high heat before adding the tuna steaks.
• Use a non-stick skillet or a well-seasoned cast-iron skillet to prevent the tuna from sticking to the pan.
• To get grill marks on your tuna steaks, cook the tuna for 45 seconds, then turn it 45 degrees and cook for another 45 seconds before flipping it over.

Grilling Tuna Steaks

• Grease the grill rack or spray it with non-stick cooking spray.
• For direct grilling on a gas or charcoal grill, place the tuna steaks over medium heat and grill for 4 to 6 minutes per 0.5-inch thickness, turning once.
• For indirect grilling, preheat the grill and reduce the heat to medium. Place the tuna steaks over a drip pan and grill for 7 to 9 minutes per 0.5-inch thickness, turning once.

Baking Tuna Steaks

• Preheat the oven to 450°F.
• Place the tuna steaks on a greased baking sheet in a single layer.
• Bake for 4 to 6 minutes per 0.5-inch thickness, or until the fish flakes with a fork but is still pink in the centre.

Tuna steak cuts

Tuna is a versatile fish that can be grilled, pan-seared, or enjoyed raw as sashimi. When it comes to selecting a tuna steak, freshness is key. Look for tuna with bright and clear eyes, vibrant red flesh, and a clean smell of the sea.

Step 1: Choosing the Perfect Tuna

Opt for tuna with a firm texture and a rich, vibrant colour. Avoid tuna with a strong fishy odour or any discolouration. If you plan on consuming it raw, it is best to choose sushi-grade tuna.

Step 2: Preparing Your Workstation

Set up a clean and organised workstation by placing a cutting board on a stable surface and keeping a sharp chef's knife nearby. This ensures safe and efficient tuna steak preparation.

Step 3: Removing the Skin

Place the fresh tuna steak skin-side down on the cutting board. Make a small incision between the flesh and the skin at one end, holding the skin firmly and gently sliding the knife through to separate them. Continue this process until the skin is completely removed.

Step 4: Cutting the Tuna into Steaks

Identify the natural lines or grain of the tuna to determine the optimal cutting direction for maximum tenderness. Using a sharp knife, make clean, even cuts across the grain to create tuna steaks of your desired thickness. For grilling or pan-searing, a thickness of 1 inch (2.5 cm) is recommended.

Step 5: Seasoning and Cooking

Now, you can season the tuna steaks according to your taste preferences. Popular seasonings include salt, pepper, and a squeeze of lemon juice. You can also experiment with marinades or rubs to enhance the flavour. Depending on your preference, you can grill, pan-sear, or enjoy the tuna steaks raw. Remember not to overcook the tuna to avoid dryness and maintain its desirable texture.

Frequently asked questions