Food Protection Connection: How Cold is Your Cold Food?

(reprinted from Dietary Manager, June 2009)

The Centers for Disease Control names improper holding temperatures as one of the top-five causes of foodborne illness (see sidebar for the list). Holding temperatures are also a key food safety factor listed in CMS guidance (F371). Yes, “Keep cold food cold” is one of our food safety mantras. But is your cold food really cold?

Retail Findings

A recent study by EcoSure, an auditing firm, revealed that up to 58 percent of retail food products fall in the danger zone (above 41°F). While temperatures were collected at grocery stores, the data suggest that just keeping foods under refrigeration does not ensure safe food temperatures. Specifically, the audit found danger zone temperatures in the following categories:

• Deli counter meats: 58%
• Pre-packaged lunch meats: 38%
• Pre-packaged deli products: 31%
• Yogurt & cottage cheese: 24-25%
• Fresh seafood: 24%
• Fresh meat: 17%

What’s interesting is that food held in backroom refrigerators averaged about 36°F, well below the danger zone mark. These findings underscore the challenge of cold holding in any flow of food.

Now consider these next steps—transportation and storage. In the consumer scenario, cold foods spend just over an hour out of refrigeration. Just the first 15 minutes out of refrigeration led to a temperature increase of 5°F, according to the study. For frozen products, half an hour at room temperature boosted temperature almost 8°F.

Cumulative Temperature Abuse

Not sure whether these little temperature lapses are important? Consider the concept of cumulative temperature abuse—minutes a food spends out of temperature control during the entire flow of food. What if there are 30 minutes on the receiving dock and in the hallways waiting for storage? And also 45 minutes as food is being withdrawn from inventory prior to preparation? Maybe 90 minutes during food preparation? And perhaps another 60 minutes during cooling of hot foods? And 30 minutes in re-heating? In this example, food spends more than 4 hours in the danger zone and is, by FDA standards, unsafe to eat.

In fact, an FDA examination of cold holding factors in a variety of foodservice operations nationwide determined that three of 10 nursing homes were “out of compliance” for maintaining cold holding temperature for potentially hazardous foods at 41° or below (see Food Protection Connection—"FDA Issues 'Report Card'"—November/December 2004).

FDA Advice—Monitoring Cold Temperatures

In its HACCP Manual for Food Service, the FDA advises using internal product temperature checks to verify that cold foods indeed are cold. The FDA adds, “You should assess whether it is realistic and practical for you to do this depending on the volume of food you are storing.”

Another method suggested by the FDA is monitoring ambient (air) temperature in refrigeration units. How often you should record these temperatures depends on five factors, according to the FDA:

• “Whether the air temperature of the refrigerator accurately reflects the internal product temperature
• “The capacity and use of your refrigeration equipment
• “The volume and type of food products stored in your cold storage units
• “The prerequisite programs that support monitoring this process
• “Shift changes, volume of business, and other operational considerations.”

Ultimately, food temperature and air temperature are not identical. Typical advice is to maintain air temperature at about 38°F to ensure a safe food temperature. This warrants some tests and checks in your own operation, however. Refrigeration temperatures depend not only on the thermostat, but on how your unit works and how often doors are open. If you rely on air temperatures, try spotchecking food temperatures to verify that your controls are working. This is part of the HACCP process.

For cold holding of foods that depend on refrigeration as a food safety control—such as deli meats or potato salad—the FDA also suggests creating a “safety cushion” when setting standards. Make the critical limit lower than 41°F. You want to catch a cold food before it creeps into the danger zone and make needed corrections.

In cold holding service areas, it’s worth gleaning some tips from the retail audit described above. Thermostats alone may not do the job of ensuring food safety. Product monitoring is sound protection.

When cooks are busy monitoring endpoint and holding temperatures for hot foods, it’s easy to forget that cold foods are equally critical. Foodservice workers can think of cold holding as a team challenge, because the controls each person exerts at various stages in the flow of food unite to control the growth of pathogens. The upshot is safe food for customers.

by Sue Grossbauer, RD
Sue Grossbauer, RD is the author of several books and a regular contributor to DIETARY MANAGER magazine.