A brief nutritional approach

Food irradiation is a preservation method comparable to others that use heat. Some advantages and disadvantages are discussed. Ionizing radiations provided by specific radioactive substances: Cobalt-60 and Cesium-137, or by machines (electron accelerators and X-ray devices), are employed to eliminate living organisms which are harmful to human health or cause food spoilage. Several applications are listed. As any other food preservation method, it does not substitute good manufacturing practices but complements them. Being perhaps the most studied food preservation method, its wholesomeness is guaranteed by the World Health Organization (WHO), the Food and Agricultural Organization (FAO), the International Atomic Energy Agency (IAEA), the American Medical Association, The American Dietists Association, among others. Like in any other food preservation method, some nutritional and sensory losses can occur after an irradiation treatment; so, processing conditions are chosen to minimize these changes. Generally, nutrients are well protected within the food because there are many different molecules able to react with radiation. Some significant nutrient losses referred to in literature are usually found only when irradiating experimental mixtures of an isolated diluted food component and water. The evaluation concludes that macro nutrients like proteins, lipids and carbohydrates are scarcely altered in their nutritional value after a treatment carried out under good irradiation practices. Regarding micro nutrients, minerals are stable, and some vitamins are slightly sensitive, mainly thiamine, ascorbic acid, and tocopherols, being their losses smaller than 15 - 20% which are comparable with those found in foods preserved by other methods. Besides, the impact that food irradiation would have on consumers' vitamins intake should be assessed considering the whole diet contribution, as many products are not likely to be irradiated. Confidence in food irradiation is such that in some countries, for instance United Kingdom and United States, it has been used to feed immunocompromised patients in hospitals. In Argentina recently a whole irradiated lunch was tasted by 44 of those patients, with very good acceptance. The aim was to enrich their diets with fresh produce or minimally processed foods, more nutritious and palatable but usually forbidden because of the risk of food borne diseases. (author)