Tuna lovers know that ahi is different from albacore and comes with a host of qualifications
A fresh oceany smell, translucent ruby flesh, and a nice shiny sheen all suggest the fish is top-quality and fresh
Even if you aren't looking for a sushi-grade ingredient, these three factors are important for identifying the rough quality of ahi tuna at first glance.
If you see something that's slightly matte brown, dry, and reeks overwhelmingly of fish, avoid it at all costs.
Brown on any raw meat means it has oxidized from exposure to air, and the smell of bad fish comes from bacterial growth and the breakdown
If your tuna comes packaged, check to see if the label includes mention of any added artificial color.
It's important to note that one way to preserve the color of fresh ahi is to gas it with carbon monoxide.
The FDA declared this Generally Recognized as Safe and requires providers to label gassed ahi tuna as such.