Current Weather
The Spy FM

Freezing Food Doesn’t Kill E. Coli And Other Germs

Filed by KOSU News in US News.
April 5, 2013

Think that freezing food kills E. coli and other nasty microbes? Think again.

That’s the lesson from the new E. coli outbreak caused by frozen chicken quesadillas and other snacks that has sickened 24 people in 15 states.

Freezing does slow down the microbes that cause food to spoil, but it’s pretty much useless for killing dangerous bugs.

“It actually does a pretty good job of preserving many of the pathogens and microbes that will cause problems later if thawed out,” says Trevor Suslow, an extension research specialist at the University of California, Davis, who studies food safety.

The strain of E. coli — shiga toxin-producing 0121 — involved in the current outbreak hasn’t been seen in frozen food before, but other pathogens have caused illness through frozen foods like pot pies, says Martin Wiedmann, a professor of food science at Cornell University. He is working with Rich Products Corporation of Buffalo, N.Y., producer of the foods involved in the outbreak, to figure out the source of the contamination.

A product recall first issued last week was expanded Thursday to include all food produced at the company’s Waycross, Ga., plant. Its frozen snacks, cheesesteak sandwiches, and the like are sold nationwide.

Weidmann also wasn’t surprised to hear that frozen food could harbor E. coli. “We store a lot of microbes in the lab,” he says. “The easiest way is at minus 80 degrees.”

But while freezing doesn’t defeat pathogens, heat will.

Bacteria die if they’re heated to 165F. Cooking instructions on frozen food packages are designed to deliver a temperature of 165F to the coldest part of the product, according to the Grocery Manufacturers Association.

The foods involved in this outbreak are all meant to be cooked, not just warmed up, before they’re eaten. Snacky foods like mini pizza slices and cheese steaks implicated in the outbreak are often heated in microwaves, and microwave ovens are notorious for heating food unevenly. Thus the sometimes-intricate package instructions involving turning, stirring, and waiting.

The median age of the people who have fallen ill is 17. It’s easy to imagine a scenario where a hungry teenager briefly nukes the pizza dippers and dives in. That’s not to say that’s what happened in this outbreak. “I don’t mean by any stretch to imply that the consumer is at fault here,” Wiedmann says.

But safe equals piping hot when it comes to frozen foods. Wiedmann says the most foolproof way to do that is to give up the convenience of the microwave and put foods that require cooking in the oven for a good hot bake.

“With a frozen ready-to-cook food, I would always go with the stove, not the microwave,” he says. [Copyright 2013 NPR]

Leave a Reply

12AM to 5AM The Spy

The Spy

An eclectic mix of the Spy's library of more than 10,000 songs curated by Ferris O'Brien.

Listen Live Now!

5AM to 9AM Morning Edition

Morning Edition

For more than two decades, NPR's Morning Edition has prepared listeners for the day ahead with two hours of up-to-the-minute news, background analysis, commentary, and coverage of arts and sports.

View the program guide!

9AM to 10AM The Takeaway

The Takeaway

A fresh alternative in morning news, "The Takeaway" provides a breadth and depth of world, national and regional news coverage that is unprecedented in public media.

View the program guide!

Upcoming Events in your area (Submit your event today!)

Streaming audio and podcasts

Stream KOSU on your smartphone

Phone Streaming

SmartPhone listening options on this page are intended for many iPhones, Blackberries, etc. with low-cost software applications available to listen to our full-time web streams, both News on KOSU-1 and Classical on KOSU-2.

Learn more about our complete range of streaming services

We're perfecting the patient experience - Stillwater Medical Center