Relaxation behaviour and dose dependence of radiation induced radicals in irradiated mango

Kameya, Hiromi*; Kakita, Daisuke*; Kaimori, Yoshihiko*; Kikuchi, Masahiro; Kobayashi, Yasuhiko; Ukai, Mitsuko*; Shimoyama, Yuhei

Mangoes are imported to Japan after treated with hot water. Recently, irradiated mangoes imported to U. S. are widely used. This paper reports on the ESR method for analyzing the radiation induced radicals of irradiated mangoes. Upon the ray irradiation, a strong signal peak in the flesh and skin of mangoes was observed at = 2.004. This singlet peak may be attributed to organic free radicals. The ESR spectra of the flesh and skin of mangoes showed the radiation induced radicals due to cellulose by irradiation over 12 kGy. The relaxation time (T1 and T2) of the singlet signal were calculated. T2 showed dose response according to increasing the irradiation dose levels, while T1 was almost constant. The value of (T1T2)1/2 showed the dependence of irradiation dose level.