Two studies recently published in the journal Food Control found that several consumer-grade commercial meats contained species other than what was on their labels, including horsemeat.

The studies were undertaken by researchers in Chapman University’s Food Science Program (Calif.). 

Forty-eight fresh and frozen ground meat products of varying species were gathered for the first study, which aimed to identify species. The samples were tested using a combination of DNA barcoding and real-time polymerase chain reaction.

Of the samples analyzed, 10 were found to be mislabeled, and of those 10, nine had an additional meat species. One sample was completely mislabeled, and horsemeat was found in two of the samples.

The second study focused on game meat species labeling, using 54 game meat products from online retail sites in the United States. Based on their labels, 22 different types of game meat were represented, but the study found that 10 products were potentially mislabeled. One example was a product labeled as black bear that was identified by researchers as American beaver.

The studies concluded that the presence of multiple species in samples might be due to cross-contamination at the processing facility, and that unintentional mislabeling may occur when several species are ground without properly cleaning the machinery between species. Another conclusion was that lower-cost species were being intentionally mixed in with higher-cost species for “economic gain.”

Horsemeat cannot be sold for human consumption in the United States, and there is a ban on horse slaughter.

A 2013 horsemeat scandal in Great Britain and Ireland, countries not known for consuming horsemeat, led to millions of meat products being pulled from grocery stores shelves and production suspended at several meat-processing plants.

“Although extensive meat species testing has been carried out in Europe in light of the 2013 horsemeat scandal, there has been limited research carried out on this topic in the United States,” said Rosalee Hellberg Ph.D., assistant professor at Chapman University and co-author on both studies, in a news release. “To our knowledge, the most recent U.S. meat survey was published in 1995.” 

Game meats produced in the United States are regulated by the U.S. Department of Agriculture, while the Food and Drug Administration regulates game meats imported. The FDA defines game meats as exotic meats, animals and birds that are not regulated in the Meat and Poultry Act.

The USDA and FDA do not require genetic testing of meat to determine if it’s from a particular animal, but after the 2013 horsemeat scandal the USDA did step up efforts on “species testing” of imported meats from April 2013 to April 2014.