Keith Warriner, Ph.D., is a professor of food science at the University of Guelph. He is also the food science graduate coordinator of the department’s Master of Science and Ph.D. food science programs.

After completing his Ph.D. in microbial physiology at the University College of Wales, he worked for the Department of Medicine at the University of Manchester where he studied biosensors. He also attended the University of Nottingham as a research fellow in food microbiology, working with fresh produce.

He joined the Department of Food Science at the University of Guelph in 2002 and was promoted to full professor in 2011. He is the former president of the Ontario Food Protection Association, a member of the International Association of Food Protection, is an associate editor of the Canadian Journal of Microbiology, and is on the editorial board for Applied & Environmental Microbiology and International Journal of Food Microbiology.

​Keith's research revolves around food safety and food microbiology, allowing him to work closely with industry and apply his research findings in a practical way.

Keith was previously interviewed for Episode 37 of Food Safety Matters.

In this episode of Food Safety Matters, we speak to Keith [14:30] about:

• The history of Henry Fenton, the Fenton reaction, and the Fenton reagent
• The use of water, hydrogen peroxide, and UV light to kill pollutants, pesticides, etc.
• Applying hydroxyl radicals to fresh produce including spinach and other leafy greens
• The advanced oxidation process (AOP) and why it's so problematic with tomatoes
•  How the 2006 spinach outbreak change the leafy greens industry's outlook on food safety
• Thoughts on how to address polluted water affecting leafy greens and how his process would likely be effective
• The George Weston Seeding Innovation Program
• Why washing is so problematic in preventing cross-contamination in leafy greens
• What matters to food companies when it comes to AOP
• AOP's use with meat and fish
• The current pandemic, N95 masks, and how food recalls have been affected

News Mentioned in This Episode
FDA: Nearby Cattle Grazing Land Likely to Blame for Late 2019 Romaine Lettuce Outbreaks [7:50]
Pandemic Challenges Highlight the Importance of New Era of Smarter Food Safety [11:22]

Campbell Mitchell, M.B.A. is Head of Food Safety and Compliance for Kraft Heinz North America. He has more than 30 years of international experience in food safety, quality management, and risk mitigation. Prior to joining Kraft Heinz, Campbell served as Vice President of Quality and Safety at Fairlife LLC, a $4-billion Coca-Cola-owned dairy brand. He has also held senior leadership roles with Kerry Group and Almarai in the Middle East. Additionally, he founded a consultancy that supported Tiger Brands in Africa.

Helena Bottemiller Evich is the Founder and Editor-in-Chief of Food Fix. She previously led coverage of food and agriculture at POLITICO for nearly a decade, winning numerous awards for her work, including a prestigious George Polk Award for a series on climate change and two James Beard Awards for features on nutrition and science. In 2022, she was a James Beard Award finalist for a deep dive on diet-related diseases and COVID-19. Helena is also a sought-after speaker and commentator on food issues, appearing on CNN, MSNBC, CBS, BBC, NPR, and other outlets. Her work is widely cited in the media and has also been published in the Columbia Journalism Review and on NBC News.

Frank Yiannas, M.P.H. is a renowned food safety leader and executive, food system futurist, author, professor, past president of the International Association of Food Protection (IAFP), and advocate for consumers. Most recently, he served under two different administrations as the Deputy Commissioner for Food Policy and Response at the U.S. Food and Drug Administration (FDA), a position he held from 2018–2023, after spending 30 years in leadership roles with Walmart and the Walt Disney Company.

Drew McDonald is the Senior Vice President of Quality and Food Safety at Taylor Fresh Foods in Salinas, California, where he oversees the quality and food safety programs across the foodservice, retail, and deli operations under both FDA and U.S. Department of Agriculture (USDA) jurisdictions. Mr. McDonald works with an impressive team developing and managing appropriate and practical quality and food safety programs for fresh food and produce products. He has more than 30 years of experience in fresh produce and fresh foods.

John Besser, Ph.D. worked for ten years as Deputy Chief of the Enteric Diseases Laboratory Branch at the U.S. Centers for Disease Control and Prevention (CDC), where he was involved in national and global programs to detect, characterize, and track gastrointestinal diseases. Prior to CDC, Dr. Besser led the infectious disease laboratory at the Minnesota Department of Health (MDH) for 19 years and served as a clinical microbiologist at the University of Minnesota Hospital for five years. He currently works as an independent contractor and consultant. Dr. Besser is the author or co-author of more than 70 publications. He received his Ph.D. and M.S. degree from the University of Minnesota.

Craig Hedberg, Ph.D. is a Professor in the Division of Environmental Health Sciences at the University of Minnesota and Co-Director of the Minnesota Integrated Food Safety Center of Excellence. He promotes public health surveillance as a prerequisite for effective food control, and his work focuses on improving methods for collaboration among public health and regulatory agencies, academic researchers, and industry to improve foodborne illness surveillance and outbreak investigations.

In this year-end episode of Food Safety Matters, we round up the top stories of 2025, covering U.S. federal food safety policy changes under the Trump Administration, MAHA- and state-led moves against food additives of concern and ultra-processed foods, infant formula safety, science on Listeria and biofilms, ongoing monitoring of avian flu, and AI food safety applications.

In this episode of Food Safety Matters, we speak to legal expert Brian P. Sylvester, J.D. about the rapidly evolving U.S. food regulatory landscape under the MAHA movement, and how food companies can prepare for state and federal policy changes regarding food dyes, GRAS ingredients, ultra-processed foods, and other areas.

In this episode of Food Safety Matters, we speak to Jay Berglind, the CEO of Aegis Foods and the maker of Fearless Eggs, known for its novel pasteurization process. Jay discusses the science behind Fearless Eggs’ method and what sets it apart from traditional pasteurization, and the importance of food safety innovation.