Frozen fish is treated with carbon monoxide primarily to enhance and preserve its desirable bright red color, making it appear fresher for longer periods.
Preserving Color and Appearance
Carbon monoxide is utilized in the processing of certain frozen fish, particularly species like tuna, to maintain their vibrant red hue. Fish naturally undergo an oxidation process when exposed to air, which can cause their flesh to turn brown or dull. This discoloration can make the fish appear less fresh and unappetizing to consumers, even if its quality remains good.
How Carbon Monoxide Works
The application of carbon monoxide helps counteract this natural browning. It binds with myoglobin, the protein responsible for the red color in muscle tissue. This binding forms a stable compound called carboxymyoglobin, which is highly resistant to oxidation. As a result, the fish retains its bright, "fresh-looking" red color, preventing premature discoloration and maintaining its visual appeal.
Consumer Perception
The consistent bright red color achieved through carbon monoxide treatment plays a significant role in consumer perception. Consumers often associate a deep red color with freshness and high quality, which can influence their purchasing decisions. By preventing the natural browning that would otherwise occur, this treatment ensures the product remains visually appealing on shelves for an extended duration.
