The latest perpetrator of Escherichia coli (STEC), a significant cause of bacterial gastrointestinal illness, is ready-to-bake commercial prepackaged cookie dough. The discovery was made following the 2009 investigation of a nationwide (USA) outbreak of Shiga toxin-producing Escherichia coli. A new study, published online and in the Clinical Infectious Diseases describes the outbreak and provides suggestions to prevent the bacteria in a strong message for consumers: The pre-packaged cooking dough must not be eaten before baking.
Researchers of the new study, led by Karen Neil, MD, MSPH, and her team at the CDC (Centers for Disease Control and Prevention) and at the health departments of several states came to two major conclusions:
- Cookie dough manufacturers should consider reformulating their product to reach the same safety standard as ready-to-eat products
- Consumers be more effectively educated about the risks of consuming unbaked goods.
E. coli food-related illnesses have previously been linked to various foods, including leafy green vegetables, sprouts, unpasteurized apple cider, melons, salami, and ground beef. Environmental analysis, extensive back-tracing and laboratory tests of the investigation into the 2009 outbreak, resulted in a recall of 3.6 million cookie dough packages.
Investigators were unable to trace the bacteria back to any single source. Given that neither vehicles nor the production process linked to the dough could be clearly identified as having contributed to the contamination, Dr. Neil and his team suspected that the source of contamination may have been one of the ingredients used to produce the dough, and although their investigation did not conclusively implicate flour, it remains the prime suspect.
By referring to use-by dates on the tainted products over specific weeks and months, the investigators say the culprit might have been just one purchase of E. coli-containing flour that was used in producing several lots and varieties of dough.
In contrast to other ingredients in the cookie dough, such as pasteurized eggs, molasses, sugar, baking soda, and margarine, flour is typically not subject to a "kill step" that eliminates potentially present pathogens. According to Dr. Neil, chocolate was also not implicated given that the link of consuming chocolate chip cookie dough to illnesses was lower in comparison to other flavors of cookie dough.
In a concluding statement, the authors say that:
"Foods containing raw flour should be considered as possible vehicles of infection
of future outbreaks of STEC."
The researchers suggest that manufacturers should consider using heat-treated or pasteurized flour in ready-to-cook/bake products, so that shoppers may eat the dough safely without prior cooking or baking irrespective of the products' warning labels that inform consumers about the dangers of such risky eating practices. They conclude, that manufacturers should also consider reformulating ready-to-bake prepackaged cookie dough to be as safe as a ready-to-eat food item.
The authors note that consuming uncooked cookie dough seems to be a popular practice, particularly amongst young women and teenage girls. They refer to statements from several patients who reported buying the product with no intention of actually baking cookies. Given that consumer education about the health risks may not completely eliminate people's snacking habits on cookie dough, the best possible outcome would be to make the snacks safer.
Written by Petra Rattue