Selection of dosimeter systems for radiation processing of food

Most accepted dosimeter systems rely on compounds which are toxic or at least foreign to food. Their replacement by substances which are inherent in food or by compounds which are inert and might be added to food is a possible alternative. Alanine, which may be read by expensive electron spin resonance equipment or with less accuracy by lyoluminescent methods or chemical analysis, is an example of a solution to the problem. This paper discusses the application of ordinary quartz sand, which is available as a laboratory chemical compound and which at the same time is ubiquitous in the case of vegetables and fruits grown in the soil. Derived from the applicable dose range of food irradiation and with reference to dosimeter selection criteria, the application of such an unusual dosimeter system is presented. As an example, the utilization in bulk processing of grain for insect disinfestation is shown. Another aspect is the resolution of depth dose curves by the use of this dosimeter films. In the case of two-sided electron irradiations, critical situations for dose homogeneity may occur when product thickness or density varies during a production run. An example for the resulting dose distributions and of the obtainable uniformity is presented. Furthermore, inherent quartz dosimeters may be found on vegetable agricultural products and may serve to determine the applied dose in identification procedures. (author). 15 refs, 5 figs, 1 tab