ONLINE EXCLUSIVE: Toxicological Safety of Irradiated Foods

Particular attention has been drawn to a special class of cyclic compounds being formed on irradiation of lipids. A wealth of radiolytic products are formed on irradiation of, for example, triglycerides, among them fatty acids, hydrocarbons, aldehydes, ketones, esters, and dimeric and polymeric components, but to date one class of components, the 2 alkylcyclobutanones (2-ACBs), is of particular interest.

This new class of cyclic components was reported more than 30 years ago to be formed on irradiation of pure saturated triglycerides containing C₆, C₈, C₁₀, C₁₂, C₁₄, C₁₆, and C₁₈ fatty acids with a high dose (60 kGy under vacuum). These compounds were identified as the 2 alkylcyclobutanones of the same carbon number as the precursor fatty acid. It has been proposed that these compounds may result from cleavage of the acyloxy bond via the formation of a six-membered ring intermediate.

Because levels of 2-ACBs are present in sufficient (albeit µg) quantities to be considered an indirect food additive, assessment of their toxicological potential should be a priority in the science of food irradiation. It should also be recommended that any toxicological risk assessment pertaining to the 2-ACBs should be in the context of the total human diet and the potential benefit of food irradiation in reducing illnesses, hospitalizations, and deaths associated with foodborne illness.

Paracelsus, the fifteenth-century philosopher and scientist, observed that all substances are poisons; it is only a matter of dose. Although it is almost impossible to prove the absolute safety of any food or food processing technology, it is difficult to conceive—considering the toxicological database—that radiation-pasteurized foods, including meat and poultry, pose a significant risk to human health when consumed as part of a healthful, well-balanced diet. This is true especially when compared to other, “more established” food processing and preservation methodologies that have been directly associated with the formation of cancers in animals and humans.