The Truth About Sushi Grade Tuna

At Red Shell we use ONLY Bigeye tuna that is line caught in the wild and then "super frozen" retaining a 'fresher than fresh' quality. Why should that be important to customers?

Most retail sushi companies use CO (Carbon Monoxide) treated tuna. The CO process employs several processes (filtered smoke, wood smoke or tasteless smoke) to treat tuna to cease the oxidation process and prevent browning, which permanently alters the color of tuna to bright pink (think watermelons), no matter what the storage temperature or conditions are. This is not a new phenomenon and has been used in the U.S. for decades.

This practice of CO-treated tuna meat could mislead consumers into thinking that the tuna is fresher or of higher value than it actually is. The issue is the misuse of carbon monoxide to conceal tuna spoilage, as it only preserves the color of the fish, not the quality and has the potential to deceive consumers.

Consumers of fresh tuna, whether at the sushi restaurants or the supermarket, often look for deep red color which indicates that the fish is top-quality. However, it has become increasingly likely that the fish is bright red because it has been treated with carbon monoxide during processing.

At Red Shell we utilize a natural solution which is using super frozen technologies. The key to super frozen tuna comes from the eutectic point (EP), which is an ultra-low temperature of -76°F (-60°C). This is the temperature at which all chemical and biological activity is halted completely, meaning no degradation can take place. Unlike conventional freezing, which causes water loss and color change,

"Super frozen" tuna revives to the exact condition it was in before freezing, resulting in a bright, red color and high-quality flavor. Our Bigeye Tuna is "super frozen" within 2 hours of catch and guarantees customers ‘fresher than fresh’ tuna.

At Red Shell we ONLY use sustainably caught Bigeye tuna, MSC certified and the highest quality in the marketplace!

THAT is the “Red Shell Difference”!

NOTE: The Food and Drug Administration (FDA) class CO-treatment of fish as Generally Recognized as Safe (GRAS) and describe the process as harmless. The agency permits its use to preserve the color of fresh tuna, not to enhance brown tuna, and requires retailers to label treated fish, however, most do not comply. Around the world, CO-treatment of fish is illegal, as Japan, Canada, China and the European Union have banned the practice because of fears that it could be used to mask spoiled fish.