Food irradiation is a process of exposing food to ionizing radiation and the recent development is related to the use of low energy electron beams (LEEB) for microbial decontamination. The main parameters influencing the effectiveness of the LEEB food irradiation process are the dose absorbed in treated food, its uniformity on the surface and the thickness of the irradiated food layer. Either delivering a too low dose of radiation or too low energy of electrons may result in an insufficient reduction of microbial load in treated food. Thus, providing both information in reference to treated food is essential for the process characterization.

In the presented study, two dosimetry systems were used to characterize the LEEB food irradiation process and provide information essential for ensuring repeatable irradiation conditions: B3 film with RISOScan software and AerEDE/EPR alanine system.

Irradiation of different weights of peppercorns loaded in a rotating drum was performed at INCT using ILU-6 accelerator and beam of electrons of an energy 300 keV. The uniformity of the dose on the surface was ensured by samples rotation during irradiation and was characterized by B3 films and indirectly with alanine pellets mixed together with the product and submitted to the same process. Alanine was used to estimate electron beam penetration depth indirectly.

It was shown that alanine dosimetry can be implemented to monitor the routine process and demonstrate its conformity according to pre-defined and product dependent tolerance intervals. Examples of determined parameters are shown for peppercorn irradiation depending on the size of the batch and irradiation conditions i.e. dose rate and energy of electron beam.

Acknowledgement

The IAEA CRP D61025 (Poland RC 24198, France IAEA RA 24344)