Part I in a two-part series on food irradiation, with a focus on the science behind the technology.
With summer underway, barbeque season is in full swing. For some, that means a fresh salad, for others it means grilled chicken, and for others it’s biting into a juicy hamburger. Not to mention the spices that go on top as a marinade! The majority of these people will wash their lettuce and spinach before tossing their salad and grill their chicken and hamburger till it looks good and ready. Ninety-four percent of people will not use a temperature thermometer when cooking. And, most likely, none of these individuals will get a food borne illness from the food. In fact, most will continue to simply wash their lettuce and grill their beef and chicken the way they have been doing (without a thermometer) and will remain safe.
However, Ron Eustice, Executive Director of the Minnesota Beef Council, argues that this is not good enough. For those individuals, who are unaware of the ideal cooking temperature for a hamburger, there can be an additional measure undertaken to ensure food safety, he says. Enter: Food Irradiation.
The Science Behind the Science
For years, there has been a host of misinformation swarming around the topic of food irradiation, its process and its effects on food. But, with words like ionizing radiation, gamma rays, x-rays, and electron beam transfer, you’re bound to get a quizzical look from the public here and there. Let’s break it down for all of you that are not so technology and science savvy.
Food irradiation, in simplest terms, is a process that can eliminate disease-causing pathogens. It exposes food items, either packaged or in bulk, to varying doses of high-energy, invisible radiation. The process kills harmful microorganisms by disrupting their DNA, so they can no longer reproduce. Smaller doses can modify sprouting and ripening, while higher doses can potentially alter molecules in microorganisms, which can lead to a decrease in food spoilage and foodborne illnesses like E. coli O157:H7, Salmonella, Listeria, and more. According to Mike Osterholm, Director of the Center for Infectious Disease Research and Policy (CIDRAP) at the University of Minnesota, “food irradiation is a dosage-related phenomenon, just like milk pasteurization. You can go all the way from killing the pathogens, which would be the minimum pasteurization level, to complete sterilization, which kills everything that is alive in that product.”
Products such as ground beef, poultry, and produce, like spinach and Indian mangoes, and even spices are among the many food items that currently undergo food irradiation. Today, any food product that is marketed in supermarkets is required to include a Radura symbol.
The Upside vs. The Flip Side
“If we had the use of widespread irradiation today in red meat and poultry, and some areas of vegetable production, we would save many, countless lives every year, among people who die needlessly because of foodborne disease,” Osterholm says in support of food irradiation.
According to Eustice, food irradiation is the most effective technology that has the potential to reduce or eliminate harmful foodborne pathogens. According to a 2008 presentation, Eustice claimed that E. coli O157:H7 levels are reduced from 99.99 percent to 99.9999 percent after irradiation, Salmonella levels are reduced from 99 percent to 99.9 percent after irradiation, and Listeria pathogens are reduced from 99.9 percent to 99.99 percent after irradiation.
While cooking food to an ideal temperature can also remove harmful bacteria, Eustice argues that the consumer does not know proper cooking temperatures for many foods that are susceptible for pathogenic bacteria. “Every food item has a different temperature that would kill potentially pathogenic bacteria. The cooking temperature for poultry is different than the cooking temperature for ground beef” Eustice says. “And, ninety-four percent of people do not use a thermometer on a regular basis.” Due to faulty equipment, lack of knowledge of the different temperatures to kill bacteria in particular food items, and often simply lack of equipment, Eustice proposes irradiation as an additional tool of food safety.
Among the other benefits, Eustice suggests that food irradiation eliminates insects in fruits and vegetables, delays ripening of fruits and vegetables, extends freshness, and all the while, food is left virtually unchanged with no loss in vitamins or minerals.
While some opponents argue that extending the shelf life of many food products is unnatural and unhealthy, proponents, like Eustice, state that it is in fact beneficial economically, as well as from a social welfare standpoint. According to Eustice, 30 to 40 percent of the food in India is wasted before it ever gets to the people. “We know that India has a tremendous need to feed the expanding population, but when many food items do not get to the consumer because they spoil in transit or in warehouses that is a catastrophe–not only for that country, but also for those hungry people,” Eustice says. “We’ve got a population in this world that will reach 9 billion people by the year 2050. We have approximately 6 billion today. We do not have more land. We will have less land in the future. We have to use technology that is available to us today to increase food production to feed another 3 billion people within our lifetime.”
Opponents argue that by extending the shelf life of food products, people are prone to eating unnatural food. According to Osterholm, however, spoilage isn’t the problem. “The problem is the loss of that food,” Osterholm says. “Removing spoilage bacteria has very little to do with health. It has everything to do with the amount of product consumed.”
Food irradiation is environmentally friendly, proponents also argue. “We use water to grow food, we use input such as fertilizer to make the crop grow, we use labor, we use petroleum to transport the crop to the market,” Eustice says. “And 30 to 40 percent of the product actually goes out the back door and it is put in a trash bin and then eventually in a landfill–that is a tremendous cost to our environment. Food irradiation can double or triple the shelf life of most of the food items. To me, that’s the most environmentally friendly technology that we have.”
Other processes that are known to kill microorganisms include steam pasteurization. While pasteurization adds a thermal level of disinfection to a carcass of some product, irradiation is a cold process. According to Osterholm, the water activity or the steam increases the lethality due to the given temperature. “The term steam pasteurization is a misnomer,” Osterholm says. “Pasteurization is a process where you make the assumption that all potential pathogens are either destroyed or at least rendered incapable of reproducing by some host. In this case, steam pasteurization reduces, and in some cases, it reduces substantially the amount of bacteria in the carcass or any other surface that the steam past is applied. But, it does not eliminate it. It gave people a false sense of security that somehow that organism was now eliminated.”
And, the benefits don’t stop there. According to a recent taste-test conducted by the Minnesota Beef Council in Korea, people were unable to distinguish a difference between irradiated food and non-irradiated products. In fact, the Beef Council has conducted n
umerous taste studies, including one with the Food Irradiation Processing Alliance, where they tested irradiated spinach. “People preferred the irradiated spinach to the one over the non-irradiated in some cases,” Eustice says. “It is impossible for the average person to distinguish the taste between irradiated food and non-irradiated food when the manufacturer follows the guidelines and recommendations for the proper dosage, like anything else,” Eustice says.
It is also important to note that according to Eustice and studies carried out by the Beef Council, irradiated food items do not lose vitamins. Like any process, including cooking, canning, and freezing, nutritional content is lost. According to the FDA, the nutritional loss from irradiation is insignificant. And, in the case of fruit, some irradiated fruit can be shipped riper, and thus results in higher vitamin A and C content, Eustice stated in a 2008 presentation. “It is a very environmentally friendly technology that will do for ground beef and produce and other foods what pasteurization did for milk,” Eustice says.
Food irradiation is permitted in more than 40 countries. Among the number of groups that support food irradiation are the American Medical Association, World Health Association, Centers for Disease Control and Prevention, Institute of Food Technologists, U.S. Food and Drug Administration, as well as every scientific and medical organization. “[Food irradiation] has unanimous endorsement of the scientific and medical communities. There is no other technology that has unanimous endorsement,” Eustice says.