By: Alaka AbdulQuadri, University of Ibadan
What will your expression be if after you might have finished eating a plate of rice served with ground beef and a chilled soft drink you realize that the ground beef had been irradiated? From experience, I can justifiably say 90% of such victims will be in dilemma as to whether the food consumed is safe or not. But why the quandary you must subject yourself to? I guess that is radiophobia. Dear! Do you know that irradiating food doesn’t make it radioactive? Interestingly, it can be a veritable tool to safeguard your food from critical food borne infections.
For you to know, when it comes to irradiation, you might need a primer. Simply put, irradiation — first approved by the FDA in 1963 to control insects in wheat and flour — is a non-thermal and non-chemical preservative method through which microbes in food can be killed when foods are exposed to radiant energy (such as γ-rays, electron beams and x- rays) during which a prescribed dose is absorbed. Dosages of irradiation not more than 10 kGy on average would not result in problems of toxicity and nutrition loss while ensuring microbial safety of foods.
Different foods are treated with different dosages. To extend the shelf-life and improve some technological qualities of foods are part of major reasons for the use of food irradiation. Through irradiation, unacceptable high bacterial loaded foods could be made otherwise saleable. Several bacteria (such as E.coli, Campylobacter jejuni, Salmonella, Listeria monocytogenes etc.) responsible for incurable infections can be immensely got rid of through irradiation. Numerous studies have shown that irradiation eliminates bacteria and parasites that Centers for Disease Control say are responsible for 10,000 deaths in the United States.
Put differently, a number of other useful applications of food irradiation can be highlighted. Such applications include inhibition of sprouting of vegetables, insect disinfestation of fruits and control of ripening. Sprouting –a major cause of loss in root crops (potatoes, onions, yams, etc.) can be effectively inhibited by irradiation with low doses. Unconditionally, the use of irradiation in prevention of sprouting has been granted approval in countries like U.S.A, China, Japan, and South Africa.
Grains and tropical fruits that have been infested with insects, thus lowering their sale potential, when treated with low doses (below 1kGy) can be effectively disinfested while shelf –life extension is simultaneously achieved by delaying ripening. Ripening and maturation of fruits and vegetables are also arrested by inhibiting hormone production and interrupting the biochemical processes of cell division and growth.
Just before you ask, of course, the use of irradiation in food processing and preservation has a number of limitations. To start with, if spoilage micro-organisms are destroyed but pathogenic bacteria are not, consumers will have no indication of the unwholesomeness of a food. Also, there could be a health hazard issue if toxin-producing bacteria are destroyed after they have contaminated the food with toxins. Loss of nutritional value and possible development of resistance to radiation in micro-organism could be also be very challenging later.
However, for the sake of safety, the concerns earlier stated have been addressed by the joint FAO/IAEA/WHO expert committee on the Wholesomeness of Irradiated food (JECFI) which concluded that the maximum average dose of 10kGy ‘presents no technological hazard and no special nutritional or microbiological problems in foods’ (World Health Organization, 1977, 1981). To this end, irradiated foods are safe to eat, have longer shelf-life and are nutritiously stable.