Purdue University Graduate School
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posted on 2022-04-28, 19:41 authored by Merlyn Suzanne ThomasMerlyn Suzanne Thomas, Yaohua Feng

Behavior change is not a product of knowledge alone but by the other constructs within the Theory of Planned Behavior (TPB). This includes attitude, subjective norms, and perceived behavioral control. In order to ensure positive change in food safety behavior, researchers should explore the current situation before providing the necessary resources for consumers. This can be done through consumer needs assessments which explore practices, perceptions, demographics, and more. Along with that, major health events like the COVID-19 pandemic can increase risk perceptions of consumers which may lead them to follow safe (washing hands with soap and water) and unsafe food handling behaviors (washing fruits and vegetables with soap). Information spreads quicker during this digital age and this can cause consumers to follow certain behaviors. To assess information being spread, chapter 2 includes a study assessing COVID-19-related food safety information on YouTube early on in the pandemic. Chapter 3 and 4 contain longitudinal studies that used surveys and focus groups to assess consumer food handling practices and risk perceptions throughout the pandemic. Another factor is the type of food being handled. Consumers are not aware that certain foods like pet food (Ch. 5) and raw wheat flour (Ch. 6) can cause foodborne illness. Thus, they may not be handling these types of products as carefully. It is important to communicate that these foods can also cause foodborne illness. In the case of raw wheat flour, while commercial brands provide food safety messages on the packaging, consumers have a hard time finding and understanding the messages. All the studies within this dissertation explored multiple elements that can fall under the different constructs of the TPB in the context of the different factors that affect food safety behaviors. For example, previous studies have found that risk perception may fall under the construct of attitude because human perceptions can influence how a person feels about the situation. The objective of this dissertation is to explore different consumer food safety needs and explore how the elements within the needs assessments feeds into the TPB. With this information, researchers can advance the use of the TPB and researchers and food safety educators can ensure positive behavior change through the TPB.


National Institute of Food and Agriculture, U.S. Department of Agriculture, Hatch project 1016049 (YF)and 2020-68012- 31822 (MT, ZB, IB, RS, ML)


Degree Type

  • Doctor of Philosophy


  • Food Science

Campus location

  • West Lafayette

Advisor/Supervisor/Committee Chair

Yaohua Feng

Additional Committee Member 2

Lavanya Reddivari

Additional Committee Member 3

Elizabeth Karcher

Additional Committee Member 4

Shauna C. Henley