Like not selling unrefrigerated caramel apples anymore (or until risks can be reduced to whatever level they deem acceptable). But for now, caramel apple lovers will have to find other options.
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The study also states, “The outbreak took producers, public health officials, and food safety experts by surprise: caramel-coated apples are not a food on which Listeria monocytogenes should grow”. Of 31 people interviewed, 28 of them had eaten commercially produced, prepackaged caramel apples before becoming ill.
Kroger said it made the decision based on new scientific evidence that the product, if left unrefrigerated after being pierced with a stick, could be at risk for the bacterial disease. It causes short-term symptoms such as high fever, severe headache, stiffness, nausea, abdominal pain and diarrhea.
According to researchers from the University of Wisconsin-Madison’s Food Research Institute, separately, apples and caramel are not food items that can host the growth of listeria.
The researchers found the average population of L. monocytogenes increased 1,000 fold on caramel apples with sticks stored at room temperature for three days. The groups of apples were further split up, and stored at either 44.6 degrees Fahrenheit or 77 degrees Fahrenheit for up to four weeks in order to test the effects of both temperature and time on the growth of listeria. She explained that the low water content of caramel and the acidity of apples should not promote the growth of listeria. Those without sticks showed no listerial growth after four weeks of refrigeration.
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“That wooden stick goes inside the apple, the apple juice can leak out from the apple onto the stick and you’ve got this sweet and wet place for the bacteria to grow”, Dr. Katy Griene from Baylor Scott & White said. Then, of course, they dipped the apples without sticks into the caramel by using tongs, and Glass noted that the dipping provides actually protects from bacteria. “But because caramel-dipped apples are typically set out at room temperature for multiple days, maybe up to 2 weeks, it is enough time for the bacteria to grow”.
