Best-selling celebrity cookbooks are giving bad advice on hygiene and some provide little information on how to avoid food poisoning, researchers have warned.

Recipes involving meat products often do not include adequate warnings or information about what the endpoint temperatures should be, a study found.

Researchers from North Carolina State University analysed nearly 1,500 recipes from 29 cookbooks, which they say includes, amongst others, Gwyneth Paltrow's It's All Good.

Other examples of chefs whose cookbooks fell short of offering readers enough safety advice include Giada De Laurentiis, presenter of the Food Network, Ina Garten, better known as the Barefoot Contessa, and Rachel Ray.

One review of Paltrow's
One review of Paltrow's "It's All Good" cookbook described it as "characterised by a complete fear of food." Photo / Getty

The researchers warned that some of the recipes studied contained incorrect information, while others gave no direction at all.

Professor Ben Chapman said: "Cookbooks aren't widely viewed as a primary source of food safety information. But cookbook sales are strong and they are intended to be instructional."

He cited as an example a recipe found in one of the books for rotisserie-style roast chicken.

"It's one... that does not have a safe endpoint temperature included - which should be 165F or 74C to ensure you destroy disease causing bacteria," he said.

Poultry is a known carrier of salmonella but can be safely consumed when cooked to an appropriate internal temperature.

Prof Chapman said the researchers wanted to see if cookbooks were providing any food safety information.

All of the recipes they considered included handling raw animal ingredients such as meat, poultry, seafood or eggs.

Specifically, researchers looked whether the recipe told readers to cook the dish to a specific internal temperature, and if that temperature had been shown to be "safe". They also looked at whether the recipes perpetuated food safety myths.

They found only 123 recipes - eight per cent - mentioned cooking the dish to a specific temperature, while not all of the temperatures listed were high enough to reduce the risk of food poisoning.

Prof Chapman said: "Very few recipes provided relevant food safety information, and 34 of those 123 recipes gave readers information that was not safe.

"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."

The study, published in the British Food Journal, also found 99.7 per cent of recipes gave readers "subjective indicators" to determine when a dish was done cooking, with none to tell if a dish was safely cooked.

Katrina Levine, the study's co-author, said: "The most common indicator was cooking time, which appeared in 44 per cent of the recipes. 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."

Prof Chapman added: "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.

"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 are hoping to encourage that change."