Physical mechanisms of irradiation technologies and their characteristic effects

The search for a reliable marker of irradiated food is widespread. Presently, leading methods of identification are (1) electron spin resonance (ESR) spectroscopy to detect and quantify radiation treated meat containing bone, and (2) gas chromatography to determine lipid volatile hydrocarbons in irradiated fatty foods. Other methods based on chemical (e.g. o-tyrosine in poultry) and microbiological (Acinetobacter and Moraxella) principles show potential, but there are significant practical difficulties. Most reported work in this field uses 60Co as the source of radiation. The limited availability of 60Co will likely require that a significant part of future world capacity will have to be supplied by electron accelerators. Therefore, electron accelerators must be included in any search for a radiation marker. A key parameter that distinguishes a 60Co facility from most electron-beam facilities is the dose rate applied to the product. Any dose rate dependence of existing and future markers must, therefore, be established. In this paper, advantage is taken by the authors of the accessibility to a range of S-band and L-band linear accelerators in research and commercial operating experiments to explore specific characteristics that could lead to a key identifying parameter. (author)