Dose Distribution of Kamaboko on Package Irradiation

Abstract

Gamma irradiation of Kamaboko (a kind of fish jelly products) has been investigated to extend their shelf-life. In this study, the dose distribution in a 14×27×38cm package of Kamaboko was measured with a Fricke dosimeter, to elucidate the better irradiation conditions. The ratios of the absorbed dose in Kamaboko (D_K) to the dose in irradiation field (D_F) were almost same at the dose rate of 2×10⁵, 5×10⁴ and 1×10⁴rad/hr. When the package of 14cm thickness was irradiated at the dose rate of 3×10⁵rad/hr and reversed at half dose, the dose uniformity ratio was 1.16 in depth. The ratio was 1.11 in vertical. Therefore, the overall dose uniformity ratio was calculated from above these values as approximately 1.29. In the case of Kamaboko with wrapping film and wooden plate, smaller dose uniformity ratio in depth was obtained as 1.12. The dose uniformity ratio in the package of Kamaboko calculated from the values DK/DF almost agreed with the observed ones.