Gamma irradiation is a common Food and Drug Administration-approved method of food sterilization and preservation that exposes food to ionizing electromagnetic radiation. The method helps preserve certain foods and gives them a longer shelf life. It is also used to prevent the spread of pathogenic bacteria causing foodborne illnesses.
The FDA has approved gamma irradiation for foods including but not limited to beef, pork, poultry, shellfish, and crustaceans. As of now, the method is not approved for gamma irradiation, but a team of researchers from Nova Southeastern University hopes to change that.
Dr. Jessica Brown is an associate chemistry professor at Nova Southeastern University for the Department of Chemistry and Physics. She specializes in forensic chemistry, with much of her research focusing on the analysis of volatile organic compounds.
Through a 2026 grant from the Seafood Industry Research Fund (SIRF), Brown and her team conducted a study looking into the effects of gamma irradiation on polyunsaturated fatty acids in finfish, specifically in salmon and trout. Brown worked with her Co-Principal Investigator, Dr. Robert Smith, on the study. Smith and Brown previously conducted a similar study through a SIRF grant that examined the effects of gamma irradiation on Vitamin D concentrations in finfish.
To Brown, gamma irradiation poses an opportunity to increase food safety in the seafood industry.
“As more fish are coming into the U.S., there’s an increased chance or a highly probably chance that there could be pathogenic bacteria, especially if we don’t really know the source of the fish that are coming in, especially now that fish consumption is increasing,” Brown said. “One of the benefits of gamma irradiation would be that, even if you didn’t know the source, you can still ensure that you’re removing anything that could be unhealthy for consumers.”
Over the four quarters of the study, Brown and her team developed a version of a gas chromatography-mass spectrometry (GC-MS) method to separate and detect fatty acid methyl esters (FAMEs) from samples of frozen and chilled salmon and trout. Researchers focused on identifying and separating essential polyunsaturated fatty acids, which included alpha linolenic acid (ALA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA). The method provided a qualitative and quantitative analysis of the samples and the components they contained.
Researchers found 49 FAMEs in chilled salmon and 50 FAMEs in frozen salmon, while they found 49 FAMEs in both chilled and frozen trout samples. From their preliminary results, researchers concluded that gamma irradiation did not significantly alter the concentrations or structural integrity of essential omega-3 fatty acids and thus did not affect the samples’ nutritional value. Had the team found that gamma irradiation had altered the FAMEs in the samples, Brown said it could have forced them to look for new ways to preserve fish.
“I think that if we were to lose DHA or EPA from our fish through gamma irradiation, we would have to get creative about what type of methods we need to do to irradicate pathogenic bacteria,” Brown said.
Brown and her team are currently working on securing additional funding from the United States Department of Agriculture to help them collect more data around gamma irradiation’s effects on seafood. Brown said she hopes to eventually get their method approved by the FDA so they can add finfish to the list of foods that can be approved for gamma irradiation.
They also hope to conduct a shelf-life study to assess the stability of polyunsaturated fatty acids over time. Brown said she hopes this study will allow her and her team to learn more about the nutritional value of irradiated foods in the long-term.
By Haley Richardson, SIRF intern
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