Listeria can't grow on apples, caramel; Why caramel apples?

Listeria Can't Grow on Apples, Caramel; Why Caramel Apples?

Mmm caramel. The only thing that makes it better is when you eat it with apples.

And if you're making this combo happen — maybe with some extra toppings, like nuts or chocolate (you animal, you) — make sure you refrigerate it, too.

See more: Dole recalls spinach because of possible salmonella contamination

Because no one wants listeria bacteria. And that's a risk you take if you don't let those apples chill.
Last year's caramel apple listeria outbreak came as a bit of a surprise because, as a new study says, apples are thought to be too acidic to have listeria — and caramel doesn't have enough free water for the growth.

But, somehow, this combination killed seven people and made at least 35 ill. Listeria causes fever, muscle aches, diarrhea and other unpleasant symptoms.

Related: The riskiest foods to eat:
Risky foods to eat, food-borne illnesses
See Gallery
Listeria can't grow on apples, caramel; Why caramel apples?
Salmonella can enter tomatoes through cracks and bruises in the fruit's skin. (Photo via Getty Images)
Raw fish, like in sushi and sashimi, carries a risk of salmonella. (Photo via Getty Images)
Fermented foods such as soy sauce can be a breeding ground for flies if they are not covered properly. (Photo via Getty Images)
Raw or undercooked eggs are linked to salmonella. (Photo by Russel Wasserfall, Getty Images)
Many wild mushrooms are poisonous to humans; be cautious of where you get them from. (Photo by Adam Gault, Getty Images)
The seeds of many fruits contain toxins that can be poisonous if consumed. (Photo via Tetra Images/Getty Images)
Oysters have been linked to several illness outbreaks, as they are often consumed raw and can carry any viruses from the water they were in. (Photo via Getty Images)
Soft cheeses, like brie and feta, can carry listeria. (Photo via Getty Images)
Sprouts require humid conditions to grow, which can also spur bacteria growth. (Photo by Tom Grill via Getty Images)

In that study published in the journal mBio, researchers discovered it wasn't the apple or the caramel, but the stick inserted into the apple that caused the problem.

"Inserting a stick into the apple releases juice to the interface between the apple and caramel, providing a more hospitable environment than either component alone," a researcher said.

To test this, researchers put sticks in some apples and left some without. The refrigerated caramel apples without sticks were clean, but the refrigerated apples with sticks had slow growth. And the unrefrigerated caramel apples with sticks had significant growth. It's a good idea to refrigerate anyway, as most caramel contains milk.

And you wouldn't leave a gallon of milk sitting out either, right?

This video includes images from jlwelsh / CC BY 2.0, photogmateo / CC BY 2.0 and therealbridgetpalmer / CC BY ND 2.0.

Read Full Story

Sign up for Breaking News by AOL to get the latest breaking news alerts and updates delivered straight to your inbox.

Subscribe to our other newsletters

Emails may offer personalized content or ads. Learn more. You may unsubscribe any time.