Two researchers with Texas A&M AgriLife Research are conducting parallel projects to help reduce the risk of foodborne illness by addressing microbiological contamination in the production of produce and meat/poultry.

Addressing Listeria in Avocado Production

Alejandro Castillo, Ph.D. in Texas A&M University’s Department of Animal Science is studying foodborne pathogen contamination that occurs from lapses in sanitation and hygiene during produce processing. He is also exploring the efficacy of interventions.

Dr. Castillo’s work focuses mainly on avocados and spans the U.S. and Latin American supply chains. As much as 90 percent of the Hass avocados eaten in the U.S. are grown in Mexico, representing a large risk for contamination, but also presenting opportunities to greatly improve food safety by targeting this sector.

Recently, Dr. Castillo partnered with researchers at the University of Guadalajara in Mexico to assess the presence of Listeria monocytogenes in avocado packing plants. The team took environmental samples from equipment, floors, walls, and storage areas and tested them for generic Listeria species (to indicate where pathogenic L. monocytogenes could potentially persist).

Isolates from positive samples were sequenced to determine whether the strains had been brought in from the field or were resident strains persisting in the facility.

The same strain was found on surfaces, equipment and utensils, and storage areas in one plant, suggesting it was established in the facility and had spread through cleaning tools and movement throughout the building. These findings were used to recommend targeted sanitation and procedural improvements.

Additionally, Dr. Castillo’s lab tests intervention strategies for foodborne pathogens that can survive regular cleaning and sanitation, such as edible coatings for fruit surfaces made of natural antimicrobial compounds.

In the future, Dr. Castillo hopes to test packing processes at industry scale, explore safer alternatives to traditional brush systems, and evaluate real-world contamination scenarios.

Developing Validated Models for Meat and Poultry Safety

Matt Taylor, Ph.D. of the Texas A&M Departments of Animal Science and Food Science and Technology is working to help meat and poultry producers validate the microbial safety of their products and ensure regulatory compliance.

Dr. Taylor’s lab is known for developing mathematical and machine learning models for ready-to-eat (RTE) meat products like fermented and dried salami. With their experience developing models to determine the safety of foods that do not undergo a final kill step, Dr. Taylor’s team is building a comprehensive tool that is useful to processors of all sizes, based on existing models and new data on pathogen inactivation.

Dr. Taylor’s earlier work helped the animal byproduct rendering industry demonstrate compliance with U.S. Food and Drug Administration (FDA) regulations through experiments in which he inoculated raw rendering materials and monitored pathogen survival under different heating and holding conditions.

Helping Industry Apply Science-Based Food Safety Practices

Drs. Castillo and Taylor also collaborate with their colleagues in Texas A&M horticultural and chemical engineering projects on produce safety research. These projects include the investigation of nano- and micro-encapsulated natural antimicrobials on leafy greens, melons, and tomatoes; and tools and equipment in packing sheds to reduce contamination risks.

Together with Texas A&M AgriLife Extension Service specialists and Extension specialists nationwide, supported by the U.S. Department of Agriculture (USDA), Drs. Castillo and Taylor help growers and packers implement the validated, science-based food safety practices developed through their research.