According to a study from Clear Labs, a food analytics startup, 10% of vegetarian hot dog products contain meat.
Perhaps worse, the company found hygiene issues in four of its 21 vegetarian samples. It also found human DNA in 2% of its hot dog samples -- and two-thirds of the vegetarian samples.
Overall, 14.4% of the hot dogs and sausages tested by Clear Labs "were problematic," the company said.
Clear Foods is a company that "translates quantifiable molecular tests into actionable food data insights," according to its website. In English, that means it uses genetic sequencing to figure out just what's in your lunch.
Its results on hot dogs, released Oct. 23 through its initiative Clear Food, aren't always comforting.
Overall, the Menlo Park-based company found nutritional label inaccuracies, pork substitution and some unexpected ingredients, including chicken and lamb.
On the other hand, Clear gave high marks to a variety of manufacturers, both national and regional. Butterball, McCormick, Eckrich and Hebrew National led among national brands, each with a score of 96 out of 100, based on Clear's formula.
Clear Labs co-founders Sasan Amini and Mahni Ghorashi point out that, for all the discouraging results, overall they've seen few issues.
"Any type of problem you're reporting tends to be a minority problem if you look at the overall hot dog or sausage industry," said Amini. "This means that there are many (brands) out there that do not have any problems."
Nevertheless, Martin Wiedmann, a Cornell University professor and expert on food safety, said Clear's results lacked significance.
"This is telling us nothing new about hot dogs," he said. "It's a sensationalist marketing ploy by companies designed to sell their services."
He observed that genetic sequencing may indicate something notable -- or not. Clear's techniques are proprietary, so for outside experts, the company's results raise questions.
Clear Labs tests products for retailers and manufacturers "to do mass-scale molecular testing on their supply chains," Ghorashi said. Through its arm Clear Food, the company does aim to become more consumer focused in the years to come. Clear Food is currently the subject of a Kickstarter campaign so the company can do more reports like the one on hot dogs.
Melinda Wilkins, a professor at Michigan State University who also specializes in food safety, finds Clear's report intriguing.
"The use of genetic analysis in this type of setting is actually fascinating," she said. "I think we're going to see a lot more of this type of analysis happening, seeing how well food content matches food label."
However, she would also like more information, particularly on the finding of "human DNA."
"When you're working with genetic material, depending on the analytic technique, you can detect a very, very small amount of DNA that's not supposed to be in there," she said. "So this accusation of finding human DNA in there, you can detect a very small amount, but they're not quantifying the amount. It could be just a few cells versus a percentage content."
Clear's Amini said that, at this point, Clear can confirm that human DNA exists, but cannot confirm the specific source.
Wilkins suspects that, as genetic testing becomes more widespread -- whether from Clear or from other companies -- food manufacturers will have to react.
"The whole issue of food adulteration is starting to become a really hot area right now, and I think a lot of people became aware of the issue in meat fairly recently," she said, referring to the horse meat found in hamburgers in Britain in 2013.
"A lot of times, food adulteration issues are not a food safety concern necessarily, but still it's disturbing to think that you might be eating something that you're not aware of," she added. "So I think companies will want to be very careful about how they label, and they may want to be doing more testing of their suppliers."
"We've seen quite a bit of positive response from industry to our technology," he said. "We tend to see the progressive companies adopt our technology and similar types of technology immediately. The rest of industry tend to catch up based on changes in consumer buying behavior."