When Health Canada announced they planned to expand food irradiation to ground beef earlier this week, we had some questions. Like, what's irradiation? Are we already eating irradiated food? And mostly importantly, is irradiation safe? Luckily, Dr. Rick Holley, professor of food science in the faculty of agriculture and food sciences at the University of Manitoba, was available to teach an impromptu Irradiation 101 class. Here are his answers to our five most pressing questions.What exactly is food irradiation?
Irradiation is a food-safety measure that involves the use of high-energy electrons to kill undesirable bacteria
, like E. coli and listeria, both of which have caused serious food recalls in recent months. Holley explains that the electromagnetic energy makes changes to the bacteria’s DNA, effectively killing them. Is it safe?
Holley says there is absolutely no risk that irradiation will make your food radioactive: "The energy levels are not high enough," he explains. And he has years of research—from the World Health Organization
, American Food and Drug Administration
and even the Canadian government
—to back him up. There has been some concern about whether chemicals produced by irradiation (what researchers call radiolytic products) are potentially harmful, but experts agree the levels found after irradiation are not toxic. In fact, when you compare the chemical changes involved in food irradiation with those involved in conventional cooking methods, the changes caused by irradiation are less significant. "The benzopyrenes that form in burnt animal tissue [when you barbeque] are far more risky," Holley says.Does irradiating food change its nutritional value or taste?
Holley says that irradiation can change the nutritional profile of a food, particularly by reducing levels of thiamine (also known as vitamin
B1), but that change isn't nutritionally significant. And at the levels that irradiation are used in food, you won't notice a difference in flavour. "We did some work on beef
three years ago with a test panel here at the University of Manitoba [using] a hamburger," says Holley. "They couldn't tell the difference."How common is irradiation? Are any foods already irradiated in Canada?
"Back in the 1960s, Canada was a pioneer in the area of food irradiation," says Holley. Onions, potatoes, wheat, flour and spices have already been approved to undergo irradiation in Canada. But the process is not actually used all that often, partly because of the cost associated with the process. This is true even in countries where it's more common, like the US, which has approved beef, pork, shellfish, fresh fruits and veggies, poultry and some sprouts. "Less than 0.002 percent of food in the United States, for example, is irradiated right now," says Holley. "And the biggest application is in insect control for elimination of transport of Mediterranean fruit flies." As we see the transport of more fruits and vegetables
internationally, Holley says we'll likely see more irradiation to restrict the movement of pests from country to country. Why add ground beef to the list?
Ground beef is vulnerable to contamination by E. coli, which causes flu
-like symptoms and can be particularly dangerous for young children and the elderly. "As we see more and more instances of illness that develop from hamburger as a result of contamination by E. coli, the need to have some additional means for control becomes quite evident," says Holley. "If irradiation were brought in, in the U.S., you would have a million fewer cases of food-borne illness in that country each year. It's really quite significant, the contribution that irradiation can make to the safety of food that we eat each day."
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