Dr. Christine M. Bruhn, University of California at Davis

Dr. Christine M. Bruhn, University of California at Davis

Dr. Christine M. Bruhn is a Specialist in Cooperative Extension at University of California at Davis. Dr. Bruhn investigates consumer food handling practices, quantifies food safety concerns, explores consumer information needs, and identifies preferred sources of information. Her work investigates consumer responses to information about issues in the news that impact health and safety. Most recently, Dr. Bruhn conducted observational research focusing on consumer preparation of chicken and a salad at home. Her work will be published in the September/October issue of Food Protection Trends. 

Listen to the full recording of the BAC Fighter Knowledge Exchange conference call with Dr.Quinlan and Dr. Bruhn.

Q: You’ve just published the results of your observational study of people preparing chicken and salad at home.  How can the listeners access your research findings?

A: The manuscript will be in the September/October issue of Food Protection Trends published by the International Association for Food Protection. The web page is foodprotection.org.  Additionally Jennifer and I will present as part of a symposium at the association’s annual meeting in early August.

Q: As people who work to educate consumers about safe food handling, it is always great to have observational data.  Can you summarize what you believe are the top 3 points of interest for health educators coming out of this research?


    1. People have heard of Salmonella and are aware that chicken is a source, but they believe themselves to be very or completely knowledgeable about how to prepare chicken, and only 20% believed their family could become ill from chicken prepared in the home.  So they don’t realize they could improve their handling practices.
    2. People didn’t follow recommended hygienic practices: 64% didn’t wash hands before starting meal preparation, 38% didn’t wash hands after handling raw chicken and before touching other services and 1/3 of hand washing used water only. While they didn’t follow hand washing practices, 47% washed their chicken, a practice that is not recommended.
    3. People undercooked their chicken. Although the chicken looked adequately cooked, 40% of the chicken registered below the recommended 165°F. Of those who grilled, 52% undercooked with an average of 18° below 165°F. 

Q: Can you briefly describe for us how you conducted the study.  Summarize your methods? How was the study funded?

A: Volunteers were recruited through an interview in the mall. The food preparer must serve chicken to their family and not be currently employed in the food or medical industry. Thirty volunteers each from Los Angeles, San Francisco, Portland and Seattle were selected to reflect the ethnic diversity of these areas. People were videotaped in their home preparing a chicken dish they normally serve and either a fresh green or fruit salad. Two video cameras were set up in the home, one capturing a view of the kitchen and the other hand held by the researcher who followed the food preparer outside if the chicken was barbecued. When the preparer declared the chicken cooked the researcher took the chicken temperature with a Fisher Scientific Thermometer. In some cases a household thermometer was also used to take the chicken temperature. Finally the researcher asked the food preparer questions about food safety and chicken handling.

Q: One of the key findings of the study was that consumers are very aware of food safety issues, yet do not follow recommended food safety practices when preparing their own meals at home. What do you believe are the origins of this disconnect?  What can we all do to address it? 

A: I believe the disconnect occurs because people don’t immediately become ill when they do something wrong. Most people believe their illness is caused by something they ate at their last meal. They don’t realize that symptoms from pathogens like Salmonella, E Coli, Listeria take time to develop. We need to remind people that should they become ill, they need to look beyond their last meal.

Q: Can you tell us what has surprised you most about consumer behavior coming out of the observational work you’ve done?  

A: That people don’t adequately wash their hands is not new. We found similar results when we observed people preparing burgers and a salad in their home. I was shocked that chicken can look fully cooked and not register 165°F .  I have started using a thermometer in my own home, even when I stir fry thin chicken pieces. 

I was also surprised that the reading on home thermometers sometimes differed significantly from that on the Instant Read Fisher Scientific thermometer. Consumers were not aware that dial thermometers could be calibrated and some were 30 or more degrees different from the Fisher Scientific thermometer.

Our food safety messages need to stress that even with chicken, you can NOT rely on appearance. Use a thermometer and calibrate it frequently.

Q: Your study found that under-cooking chicken is common and even more so when barbecuing  (grilling) and stir frying. Why do you think that is the case?

A: Cooking temperature is harder to control when grilling. I think the outside gets so brown that people think the inside must also be cooked. Cooking was most uniform in oven baking. Those who are able might be advised to use lower heat in their grill and put down the lid.

The information on the thermometer can also cause confusion. Some used meat guidelines for chicken. I don’t expect people to remember all these numbers. It is helpful if thermometers clearly indicated the recommended temperatures for beef, pork, chicken, fish, and egg containing dishes.

Q: We were alarmed to find out that about 65% of the participants did not wash their hands before meal preparation. Clearly hand washing must be a major focus of education efforts.  To what do you attribute the situation of consumers and hand washing during meal preparation? 

A: I think there is an assumption in some educational materials that hands look dirty prior to washing. We need to remind people that bacteria is everywhere. You can’t see it on your hands, but your hands still need washing. Hands also need to be dried! Bacteria is transferred easiest in a moist environment. People should dry their hands with a single service paper towel. Cloth towels become contaminated after a single use. 

Q: So we’ve talked about cooking and cleaning – what about chilling? What did you find out about consumers and their refrigerators?   

A: Over half (56%) did not know the recommended refrigerator temperature. Only 26% responded correctly with 32-40° F. We placed a refrigerator thermometer where the volunteers had stored their chicken. 12% of the refrigs. were over 45°F and one was 60°F and 65% stored chicken in the middle or top shelf. People didn’t know that raw foods should be placed below cooked to avoid contamination by drips.

Q:  With so many educators on the phone – many of whom work with hundreds of consumers each year, I hope you will give your ideas for 3 actions they can take that help us turn around some of the behaviors that come out in your research?  

A: Key most important messages are:

    1. Wash your hands, especially after handing raw meat or chicken. Everything you touch can spread bacteria. Imagine chicken is covered with honey, touch it, then your refrigerator, your spices, or your cell phone, you spread the honey. You’ve got to wash to stop the stickies!
    2. Don’t wash you chicken. Bacterial splatters with the water and can spread as an aerosol. Cooking kills the bacterial. Go straight from package to cooking.
    3. Use a thermometer to be sure your chicken is cooked. Appearance is not reliable. Chicken cooked to 165°F is still moist, and it is also safe.


Visit Fightbac.org for food safety information, downloads, and tools you can use to educate people about protecting their health through safe food handling.


Government Resources

  • Foodsafety.gov
  • U.S. Department of Agriculture
  • U.S. Food and Drug Administration
  • Centers for Disease Control and Prevention

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