X-RAY machines are a common sight at the dentist’s and in hospitals, but research findings at an American university mean they may now become a regular feature at seafood processing facilities and commercial produce operations as well.

Barakat Mahmoud, an assistant professor of food safety and microbiology with the Mississippi Agricultural and Forestry Experiment Station and spokesman for the Institute of Food Technologists, is looking at the use of X-rays to decontaminate food products. He is conducting his studies at Mississippi State University’s Experimental Seafood Processing Laboratory in Pascagoula.

Mr Mahmoud’s research has shown that X-ray doses can kill bacteria that are dangerous to humans, such as salmonella, E. coli, vibrio, shigella and listeria. The process removes harmful bacteria without altering the food product in any other way. In 1963, the Food and Drug Administration deemed the irradiation of food to be a safe practice.

“Vibrios are the bacteria in raw oysters that can make them dangerous to eat,” said Mr Mahmoud. “This technology completely eliminates the naturally occurring bacteria, making the delicacy safe to consume. The X-rays do not kill the oysters; they stay alive throughout the entire process.”

The technology is also being used on fresh produce, such as spinach, lettuce and tomatoes.

He said: “The salmonella and E. coli outbreaks in fresh produce over the last few years have really brought attention to the importance of food safety. What I’ve been working on is a way to get rid of food-borne illnesses without affecting the quality and freshness of the food.”

Gary Bachman, assistant MSU Extension horticulture professor at the Coastal Research and Extension Center in Biloxi, worked with Mr Mahmoud on some of the research.

He said: “I helped select the vegetables that would benefit most from the X-ray process. Given the issues leafy greens have had with contamination, they were a good choice.”

Bachman participated in evaluating the treated vegetables and found the quality stayed consistent.

“The process doesn’t seem to affect quality,” he said. “The technology is reliable, and as a result, the vegetables are free of pathogens.”

Mahmoud uses an RS 2400 X-ray machine to do his work. He carefully wraps the food items in plastic before putting them into the machine. In a matter of a few minutes, the food is irradiated and ready to eat. The final product looks no different from when it first entered the X-ray machine.

 “The freshness of the food remains the same,” he said. “There is minor loss of vitamins A and C, but they always are reduced in any type of food processing.”

Mr Mahmoud and his colleagues found that not only does the X-ray technique kill pathogenic bacteria, but it also extends the shelf life of irradiated food. Spinach, lettuce and other fresh vegetables last 30 days longer after the spoilage bacteria are eliminated.

Processes using chlorine dioxide gas have been used in the past to rid leafy greens of dangerous bacteria, but the gas diminished the quality of the lettuce and spinach, he said. He also said gamma rays are often used for food irradiation, but X-rays are a more familiar technology for consumers.

“X-ray machines are more common, and their use can help consumers feel more secure,” he said.

Now, Mr Mahmoud and his colleagues are working to show the seafood and produce industries how useful X-ray machines will be in their operations. “We want the industry to adopt this technique as a way to make food safer,” he said.

The research is being presented at industry and academic meetings across the USA.