Electron spin resonance (ESR) studies on irradiated cocoa beans and niger seeds

Electron spin resonance (ESR) spectra of irradiated (10 kGy) and unirradiated cocoa beans and niger seeds have been compared. Unirradiated cocoa beans failed to give any ESR signal, whereas after irradiation (10 kGy) an ESR signal at g = 2.0042 was observed. However, ESR signals are given by both irradiated and unirradiated niger seeds. The intensity of signal was found to be dose-dependent up to 10 kGy for both seeds. The signals were stable up to 180 days in both cases. The results indicate the possibility of using ESR for distinguishing between irradiated and unirradiated cocoa beans but not for niger seeds. © 1997 Elsevier Science Ltd