Relaxation times of radicals induced in irradiated foods using pulse-ESR and CW-ESR

Kishida, Keigo*; Kawamura, Shoei*; Kikuchi, Masahiro; Nakamura, Hideo*; Kobayashi, Yasuhiko; Ukai, Mitsuko*

Using pulse-ESR and CW-ESR, we attempted the measurement of relaxation times (T, T) of radicals induced in irradiated foods. The specimens were black pepper and hard wheat flour. We succeeded in measurement of the field swept echo signal of irradiated specimen and in direct analysis of relaxation times (T, T). T of irradiated black pepper was 33 s, and T of irradiated hard wheat flour was 21 s. T of irradiated black pepper was 420 ns, and T of irradiated hard wheat flour was 260 ns. We also succeeded in measurement of the signal of irradiated specimens by CW-ESR. We detected the strong singlet signal from irradiated pepper, and the broad complicated signal from irradiated hard wheat flour. It suggested that the radiation-induced radicals of these two specimens are different.