The ingredients of the hot dog, America's favorite street food, contain some disturbing components that are not listed on the label, according to a report from a food analytics company that investigated what hot dogs are made up of.

Clear Food, the consumer initiative arm of Clear Labs that aims to reveal the true ingredients in food in order to help guide consumers' food and brand choices, used genomic technology in analyzing the specific components that make up 345 different types of hot dogs and sausages from 75 brands.

"Traditional food testing methods require you to know what it is you're looking for prior to testing," Clear Labs CEO Sasan Amini told Gigaom Research, adding that traditional food testing is limited to one component, which is why food tests are usually done only in response to certain issues. The process used by Clear Food is different because it identifies the components of food one by one at the molecular level.  

For its first project, the company chose to analyze the components of hot dogs because of their popularity. Americans eat about 20 billion hot dogs every year, according to the National Hog Dog and Sausage Council.

The researchers found that 14.4 percent out of the 345 hot dogs had inconsistencies in their ingredient lists. Some of them contained ingredients that were either not listed or were substituted for a listed component. For example, 10 percent of vegetarian hot dogs tested had chicken and pork meat in them. Additionally, three percent of all hot dogs tested had pork as a substitute for chicken or turkey.

The researchers also found that some of the hot dogs had hygienic issues, which was often indicated by the presence of human DNA. Traces of human DNA, usually from saliva or hair, were found in 2 percent of all hot dogs tested and in two-thirds of all vegetarian hot dogs tested.

"While some of these substitutions, hygienic issues, other variances, or off-label ingredients may be permitted by the FDA, our scientific disclosure allows you, as the consumer, to decide whether the variance or problems meet your personal standard in your buying decision," Clear Foods said in the report.

The company also found some hot dog manufacturers that are "producing high-quality hot dogs with integrity" across various types and prices of the product. Clear Foods named Butterball, McCormick and Eckrich as its top three brands, and Gardein, Taverrite's and Field to Family Natural Foods as its top three specialty and regional dog brands.