Attempts to elaborate detection methods for some irradiated food and dry ingredients

In many countries ionising radiation is increasingly used for microbial decontamination of dry food ingredients, such as spices and herbs, because this treatment causes minimal chemical alteration and few, if any, detectable changes in the flavour of spices. However, many health authorities and consumer organisations demand unequivocal tests for identification of irradiated foods. Due to the diversity and delicate chemical composition of spices, there is very little chance of developing routine chemical methods to detect a specific radiolytic product in dry spices and herbs, physical methods appear to have greater potential. Significant reduction of the gel-forming capability after irradiation could be observed in several spices. Degradation caused by ionising radiation in the volatile oils, lipids, carotenoids and starch is indicated in the near infrared (NIR) wavelength region by changes in the reflectance spectrum. The low doses of ionising radiation (for inhibition of the sprouting of tubers and bulbs) as a consequence of some histological characteristics, induce changes in the electrical impedance and derived quantities. (author)