Not all that long ago, food irradiation held great industry potential for being a safe and effective food-safety technology — for ground beef, in particular. But news on this technology has been few and far between during the past decade. So, I was pleasantly surprised to read on Monday that the Food and Drug Administration released two final rules that increase the maximum allowable dosage of irradiation in meat and poultry.

Since irradiation is considered a food additive, which should be changed but would require an act of Congress to do so — it falls under the jurisdiction of the FDA, which regulates all additives. These latest rules are the result of responding to petitions from the US Department of Agriculture’s Food Safety and Inspection Service. What’s more, it removes the limitation that any packaging used during irradiation of poultry shall not exclude oxygen.

“Regarding FDA’s action on the food additive petition on irradiation that FSIS submitted approximately 13 years ago, FDA has approved the use of irradiation on unchilled carcasses. This means that a company could irradiate product from a carcass as it moves down the dressing line on its way to the cooler, assuming safety measures are in place,” an FSIS spokesman told me Tuesday.

Rule No. 1 allows processors to irradiate unrefrigerated raw meat. It calls for a 4.5 kilogray (kGy) maximum-absorbed dose — up from the previous 3.0 kGy — of ionizing radiation to treat unrefrigerated and refrigerated raw meat, meat byproducts and “certain meat food products” to reduce foodborne pathogen levels and extend shelf-life. The rule also amends food additive regulations to increase the allowable maximum dose of ionizing radiation to 4.5 kGy for fresh poultry and 7.0 kGy for frozen poultry.

Back in December 1999, FSIS announced it was amending its regulations to permit the use of ionizing radiation for treating refrigerated or frozen uncooked meat, meat by-products and certain other meat food products to reduce levels of foodborne pathogens and to extend shelf- life. FSIS also revised its regulations governing the irradiation of poultry products so that they will be as consistent as possible with the regulations for the irradiation of meat products. The final rule became effective early in 2000.

The FSIS final rule in 2000 specified the same maximum absorbed dose levels for refrigerated and frozen meat as FDA's final rule (i.e., 4.5 kGy and 7.0 kGy, respectively). The maximum dosage allowed for poultry is 3 kGy, and the packaging of irradiated poultry must be air permeable.

For those of you unfamiliar with what the irradiation process does, the Univ. of Wisconsin Food Irradiation Education Group explains on its web site that food irradiation exposes either packaged or bulk foods to controlled amounts of ionizing radiation for a specific time to achieve certain desirable objectives.

When microbes present in the food are irradiated, the energy from the radiation breaks the bonds in the DNA molecules, causing defects in the genetic instructions. Unless this damage can be repaired, the organism will die or will be unable to reproduce. It matters if the food is frozen or fresh, because it takes larger radiation dose to kill microbes in frozen foods. The effectiveness of the process depends also on the organism’s sensitivity to irradiation, on the rate at which it can repair damaged DNA, and especially on the amount of DNA in the target organism:

• Parasites and insect pests, which have large amounts of DNA, are rapidly killed by an extremely low dose of irradiation.

• It takes more irradiation to kill bacteria because they have less DNA.

• Viruses are the smallest pathogens that have nucleic acid, and they are, in general, resistant to irradiation at doses approved for foods.

In short, irradiation is the same as pasteurization for solid foods — but it is not sterilization.
Contrary to what anti-irradiation activists say, irradiation in any of its three formats — gamma ray, electron beam or X-ray — does not make food radioactive. Although some in the industry have charged the technology has resulted in off-colors and off-tastes of treated product, proponents insist if treated using the proper dosage for the proper amount of time, product will look and taste just fine. Most important, product will be safer.

As time goes by, new food-safety ingredients and technologies will be created and tested and those that pass muster in effectiveness and affordability will surely be embraced by industry. But here’s hoping packers and processors, particularly of ground beef, don’t forget an effective food-safety tool already exists in irradiation. And when it comes to safeguarding meat and poultry, post-packaging pasteurization of any format is hard to beat regarding maximum food safety effectiveness.