Is there meat in your veggie burger? It's possible, according to Clear Labs, a company that genetically tests food products.
Clear Labs examined 258 samples from 79 brands and 22 different retailers. The samples included ground meat, frozen patties, veggie burgers and fast food burgers.
The company determined that 6.6 percent of the products contained an ingredient that was not listed on the label. In fact, there was beef DNA found in five products that were not supposed to contain beef, including two vegetarian burger products.
In addition, there were 14 products — all vegetarian — that were missing ingredients that were listed on the label. This includes a black bean burger that didn't have any black beans in it. Altogether, 23.6 percent of vegetarian products were determined to have some discrepancy between the final product and the ingredients listed on the label.
That's not where the trouble ends for veggie products, however. One vegetarian burger was determined to contain human DNA. The company notes that it was unable to uncover the source of the DNA, but it was likely from hair or skin cells.
The company found similar issues when it tested vegetarian hot dog products last year. In that study 10 percent of the vegetarian products tested contained meat. In addition, 67 percent of the vegetarian samples were recorded as having "hygienic issues," which were not described in detail.
Clear Labs also found issues with the meat samples that it tested. A fast food burger and a ground meat sample both contained rat DNA, in addition to one vegetarian burger.
In addition, seven of the 258 samples of meat tested contained a pathogen that had the potential to cause a foodborne illness. The report notes that the pathogens found in the cooked burgers were less likely to be alive and pose a smaller health risk.
"Although we did find several surprising quality issues, signaling that there are gaps in food safety and quality protocols that should be addressed, our findings suggest that the beef industry as a whole has benefited from stringent regulation and aggressive testing requirements," Clear Labs said in the report.
While Clear Labs details the percentage of various issues that were found in the samples, the company has kept the brand names anonymous.
"I don't think this report is helpful for a consumer to know if the food that they are choosing is safe or not," Mandy Carr, the senior executive director of science and product solutions for the National Cattlemen's Beef Association, told CNBC.
She raised concerns as to when the DNA discovered on the products was added, noting that the samples could have been contaminated in the lab it was tested in. Carr also noted that the study did not delve into whether the pathogens found in the meat were alive or benign, something that could have been tested.
The company did report that the cooked burgers that were flagged for pathogens were less likely to pose a health risk to consumers.
"Unfortunately, this particular report I don't find very helpful in helping us improve safety," Carr said. "And, frankly, I am concerned that it would cause consumer confusion."
Carr later said that the low number of pathogens found in the meat products was "a good sign" that the beef industry's safety measures were working.