Importance of DNA in Seafood Authentication

DNA testing of food products and ingredients is the most accurate way to identify and authenticate species, detect contaminants or adulterants, and verify label claims. It can help prevent food fraud and may help meet upcoming NOAA traceability regulations for seafood importers. This article discusses how DNA testing can help supply chain and seafood authenticity; the differences in chemical, DNA barcode, and next-generation sequencing (NGS) testing; DNA testing specific to seafood; and DNA testing as part of quality control.

As the global food supply chain becomes increasingly complex and fragmented, the challenges of safeguarding the food supply also increase. One of these challenges is protecting against food fraud and misrepresentation. Food fraud is a growing problem worldwide, costing over $49 billion annually. Economic pressure to provide cheaper food products has contributed to the fraud issue. For example Alaskan pollock being substituted for cod and steelhead trout for salmon, which causes increasingly savvy consumers to look for third-party verification of label claims.

To ensure their products are accurately identified and labeled, and contain only what is listed on the ingredient list, food companies are turning to DNA testing of products and ingredients.

Authenticity Specific to Seafood

According to the U.S. FDA, fresh fish offered in restaurants and retail stores is not always labeled correctly. A lower-cost fish such as tilapia might be labeled as a higher-value fish such as grouper. In other cases, the same fish may be marketed under different regional names or an uncommon fish name may be changed to something more familiar to consumers, even though the common name is a different genus and species (such as lingcod labeled as cod).

To encourage consistent fish labeling, the FDA developed a list of recognized seafood names that companies may use. The FDA also created a single, laboratory-validated method of generating DNA barcodes for the identification of fish for regulatory compliance. This means one set of universally accepted barcode IDs is available for companies to test any seafood.

Under the Federal Food, Drug, and Cosmetic Act, seafood must be labeled truthfully and not mislead consumers. Products that don’t comply are considered misbranded, which can result in FDA regulatory action such as a civil money penalty, no-sale order, seizure, and/or injunction. The law applies to components, packaging, and finished products, so all companies involved in handling fish—manufacturers, packers, distributors, and retailers—are responsible for assuring that they are not dealing in adulterated or misbranded products.

How DNA Testing Can Help

Being able to prove that what is on the label is what is in the product is beneficial for producers, suppliers, retailers, and consumers. It helps producers know that the ingredients they are paying for is what they are receiving.

Testing using an independent lab allows labeling ingredients and finished products as third-party DNA authenticated, which also increases consumer acceptance and allows differentiating products from competitors. In addition, authenticated food and food ingredients reduce the risk of adverse events caused by unidentified ingredients, of litigation, and of regulatory action.

DNA Testing in a Nutshell (or Lobster Shell)

DNA is the genetic code contained in cells of plants, animals, bacteria, and fungi. Parts of DNA can identify a specific individual (as in forensic or medical DNA), a broad group (such as fish), or a specific genus and species (such as tilapia).

DNA testing is appropriate for virtually any material that contains DNA in a wide range of fresh and processed products. The more processed a product is, the smaller or more fragmented the DNA samples available for extraction are. Examples from least to most processed seafood products include fresh fish (like a whole salmon or a tilapia fillet), mixed ingredients (like crab cakes), liquid extract (like fish oil), and dried extracts (like fishmeal).