Clear Labs, a U.S. based food testing company, discovered three burgers with rat DNA and one frozen vegetarian burger with human DNA in a sample of 258 burgers.
The most likely cause for human DNA is hair, skin, or fingernails that were accidentally mixed in during the manufacturing process Clear Labs reported.
The study also found two samples of beef in vegetarian products, and 12 burgers were found to have at least 100 more calories than the label listed.
From the fast food samples tested, 38 out of 47 burgers contained more calories than the menu reported.
Clear labs analyzed frozen patties, fast-food products, ground meat and veggie burgers, and found inconsistencies with ingredients.
The study found chicken, pork, beef and turkey added into products that were not supposed to have these ingredients.
Certain pathogens found in the products can cause tuberculosis-like symptoms, gastroenteritis, foodborne illness and E. coli, according to Independent.co.uk.
One of the black bean burgers tested didn’t even contain black beans.
"The FDA has set allowable limits for rat pellets in some food ingredients such as wheat because it’s impossible to remove all traces of rat DNA. It sounds gross, but you have to have to put that in perspective," Dr. Michael Doyle, professor of food microbiology at the University of Georgia said.
Clear labs won’t be releasing the names of the brands or burger chains that were tested. Instead of whistle blowing, Clear Labs goal is to work with the food industry to fix the inconsistencies.
Watch the video below to see how Clear Labs analyzes food products.