Dose responses of irradiated fresh papaya recorded on ESR at different temperature

Kikuchi, Masahiro; Ukai, Mitsuko*; Kobayashi, Yasuhiko

Electron spin resonance spectroscopy (ESR) has been utilized as a detection method of irradiated foods. However, there is a problem on ESR measurement for the water-rich foods. We have examined two techniques to solve the water problem. In two ESR detection methods for fresh fruits, dose response curves of signal intensities were obtained independently. Three responses show the direct proportional relationship, except for main peak signals of freeze-dried powders. In this study, we examined whether -induced radicals of papaya fleshes are changed after different sample preparations. The right side peak intensity is good agreement with the estimation. -induced radicals of the side peak are not affected by the sample preparations. This study indicates that the ESR detection methods for fresh fruits are reliable as a quantitative measurement.