Research at Texas A&M University in the USA has found that an electron-beam (e-beam) irradiation process can cut levels of viral contamination in raw oysters and reduce the risk of food poisoning.
The study evaluated the inactivation of hepatitis A and the norovirus research surrogate, murine norovirus-1 (MNV-1) in oysters (Crassostrea virginica) by the e-beam process and quantified the effect of FDA-approved e-beam doses on the infection risk of raw oysters contaminated with various levels of viruses. Both hepatitis A and human noroviruses can accumulate in shellfish that filter feed in contaminated waters.
Using microbiological risk assessment techniques, the researchers found that applying an ionizing radiation dose of 5 kilograys to a typical serving of 12 raw oysters containing 100 hepatitis A and human noroviruses would achieve a 91% reduction in the risk of hepatitis A infection and a 26% cut in the risk of norovirus infection. They conclude that, while e-beam treatment cannot eliminate viruses from raw oysters, it can reduce the risk of infection significantly.
The study is published in the journal Applied and Environmental Microbiology and an abstract can be found here.