2011 Volume 60 Issue 4 Pages 163-171
The detections of radicals induced in irradiated both fresh and dried papayas were carried out at liquid nitrogen and room temperature using electron spin resonance (ESR) spectroscopy.
Fresh papayas irradiated by the γ-rays were separated into flesh and skin that subjected to the ESR detection. The ESR spectra of the specimen at liquid-nitrogen temperature were observed clearly at a week after the γ-irradiation. Those signals were consisted from main peak at g=2.000 and side peaks at g=2.018 and 1.982. They showed a linear response against the dose. Furthermore, the side peaks from freeze-dried papaya flesh stored at 4°C were observed clearly at two weeks after the γ-irradiation. Those signals also showed the linear dose-response. The detection scheme for irradiated fresh fruits can be done by two stages:
1) A screening test of ESR signals at liquid nitrogen temperature using fresh samples.
2) A room temperature ESR measurement using freeze-dry samples.
