Most vegetarian or veggie hot dogs are made of meat analogues such as soy protein, mushroom or tofu, and are wrapped in a casing that uses plant-based ingredients.

A new genomic analysis conducted by food analytics group Clear Labs, however, revealed 10 percent of vegetarian hot dogs actually contain meat.

Human DNA in Veggie Hot Dog Samples

Researchers examined 345 hot dogs and sausages, and 14.4 percent of the samples were found to be "problematic." The food experts discovered the substitution of ingredients and also concerns over hygiene. Of the 21 vegetarian products examined, four showed hygienic issues, "when some sort of non-harmful contaminant is introduced to the hot dog."

In 2 percent of the samples, human DNA was detected, the researchers reported. Two-thirds of the items that contained human DNA were vegetarian products.

The analysis also found the presence of pork in 3 percent of the samples.

Some hot dog ingredients such as meat were not indicated on the label, leading to inaccuracies in nutritional labeling.

The researchers explained that trace amounts of meat in vegetarian products would be very disconcerting especially for consumers who abstain from meat due to ethical, religious and dietary reasons.

Veggie hot dogs and burgers contain less fat, calories, little to no saturated fat and no cholesterol, nutritionists say. People who are following a low-fat, low-cholesterol or low-calorie diet opt to eat veggie hot dogs and burgers.

Minor Issues for the Hot Dog Industry

The Clear Labs co-founders Mahni Ghorashi and Sasan Amini concluded that, while they found discouraging results, the issues overall were only few.

Amini said that if the hot dog industry is viewed as a whole, any problem tends to be a minority issue.

"This means that there are many (brands) out there that do not have any problems," he added.

However, one of the most notable findings in this study was the presence of human DNA in some samples.

More Analysis of Food Products and Labeling

Food safety specialist Melinda Wilkins from Michigan State University said that the issue of food adulteration has become a major concern for consumers and food producers, and that it was important to find out more about the presence of the human DNA.

Wilkins said that she nevertheless finds the results and the group's methodologies intriguing. She said that more genomic analyses could be applied in future studies.

"I think we're going to see a lot more of this type of analysis happening, seeing how well food content matches food label," Wilkins pointed out.

Professor Martin Wiedmann, another food safety expert from Cornell University, criticizes the results for lacking significance and says that the study does not inform the public of anything new about hot dogs.

In the United States, more than 7.3 million Americans follow a vegetarian-based diet, according to data from Vegetarian Times.