Genetic testing would stop tuna and salmon impostors before they hit shelves.
A whopping one-fifth of seafood (sampled in a recent study) worldwide isn't what it's labeled to be. In other words, it's possible you bought—and paid a pretty penny for—wild-caught salmon, but what's really in your oven is steelhead trout. Yikes. Luckily, there are measures in place to help cut back on fish fraud, including a bill headed to Congress and now, a protein database to identify fish.
According to a published in ACS Journal of Agricultural and Food Chemistry, a few scientists have developed a protein database capable of definitively identifying fish species. To create the database, the scientists used mass spectrometry, checking to see if the tech could be used to identify fish species as accurately as it can differentiate microbial species.
As it turns out, it can be. Using mass spectrometry, the scientists identified the protein profiles of 54 species of fish, including salmon, trout, swordfish, and some of the other most commonly sold fish in grocery stores and restaurants. (They knew they had positively identified the fish samples because they double-checked with DNA barcoding, a technique that could also be used to ID falsely-labeled fish—but one that would be much more expensive.) Unfortunately, in some cases, the scientists were only able to uncover the fish samples' genus—i.e., a class but not a specific subtype of fish. But the scientists believe that even a lack of super-specific results could still help the industry cut down on fish fraud.
It's unclear when or if this database will hit the larger market. Regardless, it's a promising step forward to fight fish-based fakery, which creates more problems than wasted money. Some fish contain specific allergens, toxins, and parasites that those with allergies and other sensitivities must avoid—and they simply cannot if fish is improperly labeled.