Electron-beam irradiation can inactivate rotavirus and poliovirus on lettuce and spinach, says a new study from researchers at the National Center for Electron Beam Research at Texas A&M University in College Station. Lead researcher Suresh Pillai, PhD, reported that this research is the first to specifically quantify the theoretical risk reduction for virus-related illness from the use of the technology.
“Most of the work on food irradiation for pathogen elimination has been done with ionizing radiation,” Dr. Pillai said. “Electron-beam radiation is vastly different. It’s a very high dose-rate technology, which means that it is so quick that the product does not even recognize that something has been done to it. Most studies have shown that electron-beam radiation does reduce contamination, but this is the first study to show the specific reduction in theoretical health infections associated with a particular commodity. Everybody knows it’ll work, but what nobody has done until now is to show the reduction in health risk.”
The team’s quantitative health risk estimates showed that even if a serving size of spinach were contaminated with approximately 10 rotavirus particles, electron-beam irradiation at 3 kilograys will reduce infection risks from about three in 10 people, or 30%, to about five in 100 people, or 5%.
Dr. Pillai said while norovirus is the leading cause of viral foodborne illnesses, all enteric viruses, including poliovirus and rotavirus, can cause foodborne infection that may lead to chronic disease complications.
“Fresh produce can be contaminated by enteric viruses through irrigation water containing fecal matter or by wash water that has become contaminated, plus the wild-type poliovirus is a health threat in many parts of the world,” he said. “Norovirus is our primary concern, and ultimately we hope to work with a human norovirus, but at this point there are no good methods of working with human norovirus.” Dr. Pillai’s team is now studying the method’s efficacy in shutting down a murine norovirus.
The study appears in the February edition of the Journal of Applied and Environmental Microbiology and was published online ahead of print in December.