The use of electromagnetic irradiation has been extensively studied and applied for several agricultural products in many countries. Among the various applications of ?-irradiation, normally at doses up to 10 kGy, promising results are obtained for the elimination or reduction of potentially toxic microorganisms and their metabolites (mycotoxins) as well as of the inherent allergenicity of several dry nuts/fruits. Current nutritional guidelines for quality agricultural products propose items with higher concentrations on constituents of increased functionality. Efforts are also made to control potential losses of nutraceuticals like polyphenols and unsaturated fatty acids, when the corresponding agro-food products are irradiated. To approach the above guidelines, a series of experiments were performed at doses of 1 to 10 kGy, in a Co-60 source. Chemical and biochemical analyses on Macadamia nuts, walnuts, grapes, currants, Goji berries, shallowthorns/Hippophae and red wines, initially contaminated with Aspergillus parasiticus or ochreus (aflatoxin B1, ochratoxin), showed a significant reduction of these potentially hazardous substances but only at higher doses (5-10 kGy). Concerning the allergenicity of the tested dry nuts, when these products were found to contain allergenic proteins and have received similar treatments, the most efficient doses were in the range of 3-5 kGy. As ?-irradiation gave acceptable results for the reduction of both classes of these hazardous substances (aflatoxins, allergens) some irradiated products were analyzed in order to calculate their profile on certain phytochemicals (total phenolics, antioxidant capacity and hydrolysis of unsaturated triglycerides). These quality characteristics were negatively affected at doses over 5 kGy. As an overall assessment for the potential use of ?-irradiation in the above mentioned products, it is concluded that for the elimination of potentially hazardous compounds like mycotoxins and allergens from nuts, higher doses must be applied. For farmaceuticals, these doses provoke their critical reduction.

Assessment of the effects of gamma-irradiation to produce safer and nutritious agro-foodstuffs

248th National Meeting (2014)

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