Consumer practices for monitoring doneness of cooked chicken are not always safe, according to a recent study.

Researchers surveyed 3,969 households in France, Norway, Portugal, Romania, and the United Kingdom on their personal chicken cooking practices. They also interviewed and observed these practices in 75 additional households in the same countries to investigate how European consumers consider chicken meat to be ready for consumption.

The survey revealed only 6.8 percent of the nearly 4,000 responding households across five countries indicated using a thermometer for monitoring chicken temperature during cooking.

The place of about one third of foodborne outbreaks in Europe is in the home and eating undercooked poultry is one route associated with illness.

The aim of the study, published in the journal PLOS ONE, was to investigate whether actual and recommended practices for monitoring chicken is done are safe. Work was supported by the European Commission through a grant as part of the SafeConsume project.

Role for consumers and authorities
Scientists from Norwegian research institute Nofima said advice from experts is not fully adopted by the public while recommendations from authorities on monitoring doneness of chicken and consumer practices do not ensure reduction of pathogens to safe levels.

“It is worrying that the advice on chicken cooking from the authorities or organizations working with food safety communication towards consumers are not always safe or likely to be adopted by consumers,” said researchers.

The field study identified nine approaches for deciding if chicken was properly cooked. Among these, checking color of the meat was commonly used and perceived as a way of mitigating risks among the consumers.

A quantitative survey revealed almost half of households check cooking status from the inside color. Other common methods include examining meat texture or juice color. Young men rely more on outside meat color and less often on the juices than those over 65 years old.

The lab study showed that color change of chicken meat happened below 60 degrees C (140 degrees F), corresponding to less than 3 log reduction of Salmonella and Campylobacter. At a core temperature of 70 degrees C (158 degrees F), pathogens survived on the fillet surface not in contact with the frying pan. Cooking chicken to obtain a five log reduction is regarded as a safe cooking process in Europe and the US.  USDA recommends cooking whole poultry to a safe minimum internal temperature of 165 degrees  F as measured using a food thermometer.

Meat and juice color do not equal safety
Laboratory experiments demonstrated that color and texture are not solely reliable indicators of safety. For example, the inner color of chicken changes at a temperature too low to sufficiently inactivate pathogens.

“Consumers are often advised to use a food thermometer or check that the juices run clear to make sure that the chicken is cooked safely – we were surprised to find that these recommendations are not safe, not based on scientific evidence and rarely used by consumers,” said Solveig Langsrud, coordinator of the SafeConsume project.

“Primarily, consumers should check that all surfaces of the meat are cooked, as most bacteria are present on the surface. Secondly, they should check the core. When the core meat is fibrous and not glossy, it has reached a safe temperature.”

Researchers said meat color is not a good alternative to using a thermometer and color of the juices will not be a proper way of measuring the heat treatment.

“For the moment, the main focus should be on proper heat treatment of all surfaces (frying all meat surfaces or cooking in sauce). A combination of judgement of the color (pale for chicken fillets) and development of fibrous structure in the thickest part of the chicken meat should also be recommended.”