Salmonella contamination of bulb onions, which caused recalls across the U.S. and Canada in 2020, is the focus of a Texas A&M AgriLife Research project to help onion producers solve the problem.
Salmonella outbreaks in onions and onion products show that the pathogen might persist during production, handling or storage. This is a significant concern to the onion produce industry, researchers said.
Understanding salmonella in bulb onions
“Little is known about salmonella’s behavior related to bulb onions,” said Vijay Joshi, Ph.D., AgriLife Research assistant professor in the Department of Horticultural Sciences and systems physiologist at the Texas A&M AgriLife Research and Extension Center at Uvalde.
Joshi’s team, over the next two years, with more than $400,000 in grant support from the Center for Produce Safety, will develop an onion-specific risk reduction plan to deliver to industry.
The team will base its onion risk reduction recommendations on studies of different genetic backgrounds of salmonella. The researchers will investigate how bulb onions’ genetic and metabolic compositions – when influenced by agronomic practices, changing seasons and other environments – affect persistence of the pathogen.
Three AgriLife Research scientists join Joshi in the project:
— Alejandro Castillo, Ph.D., associate professor in the Texas A&M Department of Animal Science and Department of Food Science and Technology, Bryan-College Station.
— Daniel Leskovar, Ph.D., Department of Horticultural Sciences professor and center director, Texas A&M AgriLife center, Uvalde.
— Subas Malla, Ph.D., assistant professor of vegetable breeding and genetics, Texas A&M AgriLife center, Uvalde.
New industry tools
Industry tools emerging from the research will include new guidelines for effective salmonella management in onions; identification of varieties and practices to fight salmonella persistence; and new capacity to identify supply chain factors that allow salmonella to persist in bulb onions.
“By developing a roadmap for safe production practices, we can show salmonella’s presence in the onion supply chain,” Joshi said. “We can minimize the risk of both pre- and post-harvest contamination, creating better assurance of safe produce across the supply chain.”