4 hidden sources of allergens

Even for foodservice operators who fancy themselves savvy on safety, allergens can lurk in surprising places throughout an operation—and sometimes the problem even starts at the supplier.


Avoiding hidden sources of allergens requires vigilance, says Christine Ebert, a registered dietitian at the University of Kansas. She once worked with an incoming student who had a whopping 63 food allergies and sensitivities, from milk to amaranth. “If they have an obscure allergy or extreme anaphylactic reactions, [diners] sometimes just assume they can’t eat with us,” Ebert says. “I work to make sure they can.” She and others urge FSDs to keep these four sources of hidden allergens on their radars.

1. Shared fryers

Some operators conflate hygiene with allergens and incorrectly assume the high heat of a fryer will “kill” the allergenic properties of items such as shellfish. But the only way to avoid this kind of contamination is separate fryers. And because nothing’s foolproof, the University of Kansas warns diners that fryers are shared and could contain traces of their allergens, Ebert says.

2. Mispackaged food

At Purdue University, Dining Court Manager Barb Maughmer recalls a dinner in which the school offered chicken Kiev. The supplier sent stacks of prepared chicken dishes. But at least one box was different.

“Late in the meal, we got a note on a napkin that said: ‘Why are you trying to kill me? I’m allergic to ham,’” Maughmer says. It turned out the factory incorrectly slipped one box of chicken cordon bleu—which contains ham—into the delivery. Thankfully the student was fine, though he did eat a significant portion. “It was a big lesson for us to double-check every label, every time,” she says.

3. Supplier recipe changes

“This is one of the biggest challenges, because typically no one alerts anyone to products’ ingredient changes,” Ebert says. She and her colleagues photograph the products that arrive at their facilities, and the information is uploaded to the menu management system to catch any allergen red flags.

Another way to avoid issues: “Stock foods with clean labels, which is now trendy anyway,” says Dartmouth College Dining Services registered dietitian Elizabeth Rosenberger, adding that it’s easier to track changes in foods with four or five plain-English ingredients rather than a long, complicated label.

4. Soft drinks

The term technically is “food allergens,” but beverages also may be comprised of surprising ingredients. One of Maughmer’s colleagues had to pluck a sports drink out of the hand of camper with tree nut allergies because it contained coconut oil. 


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