If you like burgers – and let’s face it, you do – then we have some good news and some bad news. The good news is that most of the burgers in America are OK – a molecular analysis showed that there is nothing wrong in terms of nutritional content and ingredients. But a small minority was not OK.

Photo by jeffreyw.

An unsettling 14 percent of the burgers analyzed were flagged for one issue or another: either contaminants, hygienic issues, or ingredients inconsistencies.

The analysis was conducted by Clear Labs (formerly Clear Foods), a US-based genomics testing lab that analyses common foods on behalf of both consumers and the food industry. It’s not the first time they’ve done something like this, with their analysis of hot dogs last year, turning up a few nasty surprises. This time, they took 258 samples of ground meat, frozen patties, veggie burgers, and fast food sourced from 79 brands across California (yes, they even did veggie burgers). However, most of the products were not limited to that area, and they’re pretty much what you’d find all across the country.

The most common problem was substitution, with 7% of all burgers containing ingredients they weren’t supposed to, including two instances of vegetarian burgers containing traces of meat. Most of the times, it was a different type of meat, one that shouldn’t have been in the product, though there was also a case with unlisted sunchoke (Jerusalem artichoke). The report reads:

“Our tests revealed evidence of substitution in 16 products, or 6.6% of all samples. We found beef in 5 samples, chicken in 4 samples, turkey in 3 samples, pork in 2 samples, rye in 2 samples, and sunchoke in 1 sample that were not supposed to contain these ingredients.

We found beef DNA in 1 sample of ground lamb, 1 sample of ground bison, and 1 sample of ground chicken patties. We also found trace amounts of beef DNA in 2 vegetarian burger products.”

Vegetarian burgers, in particular, didn’t fare too well. The report found 15.7 percent of the vegetarian products had missing ingredients from those listed on their labels, with the worst offender being a ‘black bean vegetarian burger’ that didn’t actually contain any black beans.

“One significant problem we uncovered was a black bean vegetarian burger that lacked black beans altogether. While this may not have been an intentional omission, it uncovers a surprising and potentially serious problem with quality control in the manufacturing of vegetarian burger products.”

The incidence of hygiene problems was low, though not non-existent.

“We detected hygienic issues in just 1.6% of the samples we analyzed. The low incidence of hygienic issues surfaced by our study is a testament to the burger industry as a whole and the stringent protocols for safe food handling. As noted by the FDA, certain low levels of contamination are acceptable.”

The presence of pathogens was also reported in a number of cases. They found DNA of Yersinia pseudotuberculosis, a pathogen that can cause tuberculosis-like symptoms, in 4 samples. Again, vegetarian burgers were disproportionately at risk, with 4.3% of all products tested (11 of 258) containing pathogenic DNA, and vegetarian products accounting for four of those problematic samples. However, it should be noted that the pathogens found in meat and fast food burgers that have already been cooked are less likely to be alive, and pose less of a threat for outbreak.

Although not as big a problem, calorie representation was by far the most common issue. Basically, half of the samples contained more calories than they said on the label.

“46% of the samples we observed contained more calories than reported on labels or in menus. Among these 119 samples, we observed an average of 39.6 more calories per serving than reported on labels or menus. In 49% of the samples, we observed more carbohydrates than reported on labels or menus.”

Ultimately, the results are not disastrous, but there is certainly room for improvement. If you want to be completely safe, you should make your patties at home. Otherwise, there’s a small risk of some extra meat, and a bigger risk of some extra calories.