Our ALL Tuna items are treated with “super frozen” process, by which its freshness and color will be preserved about 2 years.
Even after 2 years, it is same as what they were caught from the sea.
Comparing to regular frozen process, super frozen fish is infinitely much fresher as it usually takes days until those fish treated with regular frozen process are served to your table.
Besides that, the most commonly retailed tuna in USA are treated with CO (Carbon Monoxide) process which prevent oxidation, so that the color keeps remaining fresh.
However, the color remains unchanged even after the fish has gone off.
Due to this huge potential risk of food-poisoning, almost all the countries are legally banning CO processed fishes, while there is no strict rule in USA for this, which is basically because there is no custom to have raw fishes meaning USA doesn’t have specific benchmark rule of bacterial count.