Why Bluefin tuna must be Frozen at -60°C

Bluefin tuna must be frozen at -60 degrees Celsius primarily for safety, quality, and preservation reasons:

1. Preventing Parasites

Freezing at -60°C helps in effectively killing parasites such as Anisakis, which are commonly found in fish.
These parasites can pose health risks to humans, particularly when consuming raw or undercooked fish, as in sushi or sashimi.

2. Preserving Quality

Bluefin tuna is prized for its texture and flavor, especially when used in sushi.
Freezing at such a low temperature helps to maintain the fish’s cell structure, ensuring that the texture remains firm and the taste fresh when it is eventually thawed.
Higher temperatures can cause ice crystals to form in the fish’s tissues, leading to a mushy texture upon thawing.

3. Preventing Oxidation

At -60°C, the oxidative processes that can cause discoloration and off-flavors in tuna are significantly slowed down.
This ensures that the tuna retains its deep red color and rich flavor, which are important qualities for both culinary presentation and taste.

4.Extended Shelf Life

Freezing at ultra-low temperatures extends the shelf life of Bluefin tuna by effectively halting microbial activity.
This is crucial for a fish that is often shipped long distances from where it is caught to where it will be consumed.

By freezing Bluefin tuna at -60°C, fish producers and sellers can ensure that the product is safe to eat, visually appealing, and retains its desired texture and taste, even after transportation and storage.