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Cookbooks give readers (mostly) bad advice on food safety

North Carolina State University

A recent study finds that bestselling cookbooks offer readers little useful advice about reducing food-safety risks, and that much of the advice they do provide is inaccurate and not based on sound science.

"Cookbooks aren't widely viewed as a primary source of food-safety information, but cookbook sales are strong and they're intended to be instructional," says Ben Chapman, senior author of a paper on the work and an associate professor of agricultural and human sciences at North Carolina State University.

"Cookbooks tell people how to cook, so we wanted to see if cookbooks were providing any food-safety information related to cooking meat, poultry, seafood or eggs, and whether they were telling people to cook in a way that could affect the risk of contracting foodborne illness," Chapman says.

To that end, the researchers evaluated a total 1,497 recipes from 29 cookbooks that appeared on the New York Times best sellers list for food and diet books. 

All of the recipes included handling raw animal ingredients: meat, poultry, seafood or eggs.

Specifically, the researchers looked at three things:

1. Does the recipe tell readers to cook the dish to a specific internal temperature?
2. If it does include a temperature, is that temperature one that has been shown to be "safe"? For example, cooking chicken to 165°F.
3. Does the recipe perpetuate food-safety myths -- such as saying to cook poultry until the juices "run clear" -- that have been proven unreliable as ways of determining if the dish has reached a safe temperature?

The researchers found that only 123 recipes -- 8 percent of those reviewed -- mentioned cooking the dish to a specific temperature. And not all of the temperatures listed were high enough to reduce the risk of foodborne illness.

"In other words, very few recipes provided relevant food-safety information, and 34 of those 123 recipes gave readers information that wasn't safe," Chapman says. 

"Put another way, only 89 out of 1,497 recipes gave readers reliable information that they could use to reduce their risk of foodborne illness."

In addition, 99.7 percent of recipes gave readers "subjective indicators" to determine when a dish was done cooking. And none of those indicators were reliable ways to tell if a dish was cooked to a safe temperature.

"The most common indicator was cooking time, which appeared in 44 percent of the recipes," says Katrina Levine, lead author of the paper and an extension associate in NC State's Department of Agricultural and Human Sciences. "And cooking time is particularly unreliable, because so many factors can affect how long it takes to cook something: the size of the dish being cooked, how cold it was before going into the oven, differences in cooking equipment, and so on."

Other common indicators used in the cookbooks included references to the color or texture of the meat, as well as vague language such as "cook until done."

"This is important because cooking meat, poultry, seafood and eggs to a safe internal temperature kills off pathogens that cause foodborne illness," Levine says. "These temperatures were established based on extensive research, targeting the most likely pathogens found in each food."

A list of safe cooking temperatures can be found at https://www.foodsafety.gov/keep/charts/mintemp.html.

"Ideally, cookbooks can help us make food tasty and reduce our risk of getting sick, so we'd like to see recipes include good endpoint cooking temperatures," Chapman says. 

"A similar study was done 25 years ago and found similar results -- so nothing has changed in the past quarter century. But by talking about these new results, we're hoping to encourage that change."