Fish Fillets and Fish Steaks in Supermarket Seafood Merchandisers
Fresh fillets and fish steaks have a very mild, fresh odor, and are firm and elastic, though when poked, fresh skinless fillets do not bounce back as much as fillets with skin.
Fresh salmon steaks and fillets are pink, but the flesh of most other fish species is white. The right seafood display case lighting can maximize the fresh appearance of fish fillets and steaks, but most supermarket fluorescent lighting tends to be strong in the green and yellow areas of the visible spectrum, which can distort the natural color of fish fillets, and make ice beds look green or yellow.
Decomposition of Retail Displays of Fish Fillets & Fish Steaks
Once a fish has been cut into fillets or steaks, it decomposes at a much faster rate than if it had been left whole. The bacteria that live in the internal organs of the fish multiply after the fish has died, and can be carried to the muscle tissue as the fish is filleted and cut into steaks.
Radiation from display case lighting raises surface temperatures of displayed fish. Comparisons of the top and bottom of a stacked flounder fillet display in an ice bed display case found temperature differences of up to 25°F.
With prolonged exposure to heat and UV radiation from fish merchandiser lighting, bacteria grow exponentially. As fish steaks and fillets decompose, they become soft and mushy, and smell fishy or sour.
The shelf life of fillets differs depending on the fish species and the temperature of the display. One study found that cod fillets lasted 14 days at 32°F, 7 days at 39°F, and 3 days at 56°F, while other types of fish lasted only one day at 50 to 69°F and 5 to 16 days at 32 to 36°F. Fish kept frozen at -22°F could last from 9 months to 2 years.