Ground meat and exotic game meats, particularly those ordered from online retailers, sometimes are mislabeled and contain different animal species according to two recent food-science studies from Chapman University in California.

The two studies, one on ground-meat products and the other on specialty game meats, used sophisticated DNA barcoding and real-time polymerase chain reaction (PCR) testing to identify the species from which meat products were derived.

In the ground-meat study, the researchers tested samples for beef, chicken, lamb, turkey, pork and horse. Of the 48 samples analyzed in this study, 38 were labeled correctly and 10 were found to be mislabeled. Nine of the mislabeled samples contained additional meat species based on real-time PCR, and one sample was mislabeled in its entirety. The researchers note that meat samples ordered from online specialty meat distributors had a 35 percent frequency of being mislabeled compared to 18 percent in samples purchased from a local butcher and 5.8 percent in samples purchased at local supermarkets. Horsemeat, which is illegal to sell on the U.S. commercial market, was detected in two of the samples acquired from online specialty meat distributors.

The researchers suspect some of the mislabeling is due to cross-contamination from equipment in facilities that process meat from multiple species. In some other cases, the mixing could be intentional, with processors substituting some lower-priced meat in their ground product.

In the study on game meats, the researchers tested 54 samples of whole-cut game meats from online distributors in the United States.  DNA testing showed 18.5 percent of samples were potentially mislabeled. The researchers note the samples appeared to have been mislabeled either for economic gain or due to product mishandling, and add that over half of species substitutions may have been economically motivated.

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