Immediately Actionable Insights for Industry

Irrigation water treatment. Research led by the University of Arizona demonstrated that consistent use of peracetic acid (PAA) and calcium hypochlorite in irrigation water for lettuce crops significantly reduced Escherichia coli risk from aerosol deposition, animal intrusion, and treatment failures. However, the risk of pathogens being introduced to crops by animal feces is better controlled by animal intrusion prevention than by irrigation water treatment with residual sanitizer.

Simplified field surveillance. A project from the University of Illinois at Urbana-Champaign validated bootie and drag swabs as effective alternatives to soil grabs for detecting aerobic plate counts, coliforms, and generic E. coli. Additionally, alternative methods to the traditional skim milk wetting agent performed well, and avoid allergens.

Effective sanitizer use in wash water. Peach packinghouse trials led by Washington State University assessed critical operating parameters for commercially used sanitizers against important foodborne pathogens. Researchers introduced Enterococcus faecium as a non-pathogenic surrogate for Listeria monocytogenes and Salmonella in peach wash systems. Trials showed sanitizer concentration was more critical than contact time, and they demonstrated significant reductions in pathogen load.

Reinforcing Best Practices

Listeria monocytogenes on pears in cold storage. Two studies by Virginia Tech and Washington State University research teams confirmed that L. monocytogenes levels on pears decline during cold storage, though not completely. Antimicrobial paper wrapping and packing line processing improved microbial safety and reduced spoilage.

Predictive factors for fecal contamination of crops grown near animal operations. A Purdue University project found that considering weather factors—especially rainfall—in combination with setback distance is more predictive (up to 77 percent accuracy) of fecal contamination of crops grown near animal operations than setback distance alone (12–54 percent accuracy). A new risk modeling tool using Bacteroidales indicators is now available for growers.

Controlled environment agriculture (CEA) microbial contamination risks. Researchers from the Segura Center for Soil Science and Applied Biology in the Spanish Higher Council for Scientific Research (CEBAS-CSIC) Espinardo Campus identified pathogen contamination routes in CEA systems, including irrigation water and harvest bins. Salmonella and L. monocytoegens were investigated. Findings showed that water sources can be a primary route of contamination, soil and growing substrate can harbor pathogens, and foot/cart traffic can spread contamination through a facility. Ineffective sanitation of harvest bins was an issue, underscoring the need for validated cleaning protocols.

Emerging Concepts to Watch

Emerging research presented at the 2025 CPS Symposium introduced several promising concepts for future produce safety innovation. For example:

• Avocado seed extracts, rich in fatty alcohols, showed potential to reduce L. monocytogenes on avocado surfaces and extend shelf life
• Advances in virus detection methods improved the ability to identify infectious human norovirus and hepatitis A virus on fresh berries, addressing a critical gap in current testing
• A novel approach using fluorescence-activated cell sorting (FACS) and artificial intelligence (AI) demonstrated high accuracy in distinguishing live from dead Cyclospora surrogates, offering a potential breakthrough in parasite viability assessment
• Antimicrobials incorporated into edible coatings for stone fruits showed modest reductions in Salmonella, with minimal operational changes required—though regulatory and cost barriers remain.

Special Update: User-Friendly Supply Chain Risk Modeling Tool

CPS provided an update on the progress of an ongoing three-year project. Addressing the need for modeling tools to be usable by industry, University of Illinois at Urbana-Champaign researchers introduced a free, user-friendly Supply Chain Risk Model (SCRM) platform, featuring robust guides, tutorials, a results viewer, and downloading options.

Simulations using the SCRM revealed that failures in wash process control posed the highest recall risk. Additionally, combining process controls with testing yielded the greatest safety improvements.

While the SCRM is not designed to reliably inform users of the absolute risk of a system, it is a helpful tool for comparing the effectiveness of different interventions. The model can be used to help determine where along the supply chain users will “get the best bang for their buck” in terms of risk reduction.