Florida International University scientists study radiation limits for safer seafood shipping

Scientists at Florida International University have identified a promising way to safely ship fish long distances without losing vital vitamin D, using a method already widely applied to preserve other foods – gamma irradiation.

Fatty fish are a significant source of vitamin D, which supports bone health, immunity, and reduces inflammation. In high demand globally, transporting the fish over long distances increases the risk of bacterial contamination.

Gamma irradiation, which kills bacteria without compromising taste or nutritional value, is widely used in the food industry but rarely applied to fish. A key question: Does irradiation degrade the vitamin D content in fish?

To find out, researchers tested salmon and trout. Their study, published in PLOS ONE, found that vitamin D in trout remained significantly more stable during irradiation than in salmon. The difference may stem from variations in fat and water content, pointing to new possibilities for safely extending shelf life.

“We’re looking at ways to make nutritious foods safer and more accessible without sacrificing their health benefits,” said Anthony DeCaprio, co-author of the study and director of the Forensic & Analytical Toxicology Facility in FIU’s Global Forensic and Justice Center, who conducted the analyses. “This brings us one step closer to doing both.”

DeCaprio collaborated with Nova Southeastern University researchers Robert Smith and Jessica Brown. The research team collected and processed fish samples for vitamin D extraction before shipping them to FIU for analysis using mass spectrometry, a technique that identifies and measures compounds by analyzing their molecular “fingerprint.” Although the findings are preliminary, they represent an encouraging step toward seeking U.S. Department of Agriculture and Food and Drug Administration approval for the method in fish.

DeCaprio said the research could be expanded to other species and compounds, including fatty acids. With early results showing trout is highly resistant to vitamin D loss, the findings could help the food industry adopt preservation techniques that meet global demand without sacrificing nutritional quality. The researchers are now pursuing additional funding to examine how fat and water content affect vitamin D stability across different fish species.