title: Investigation of Different Factors Affecting the Electron Spin Resomance-based Characterization of Gamma-irradiated Fresh, White, and Red Ginseng.
abstract: Fresh (raw roots), white (dried), and red (steamed-drid) ginseng samples were gamma-irradiated at 0 to 7 kGy. Electron spin resonance (ESR) technique was used to characterize the irradiation status of the samples, targeting the radiation-induced cellulose radicals after different sample pretreatments. All non-irradiated samples exhibited a single central signal (g=2.006), whose intensity showed significant increase upon irradiation. The ESR spectra from the radiation-induced cellulose radicals, with two side peaks (g=2.0201 and g=1.9851) equally spaced (±3 mT) from the central signal, were also observed in the irradiated samples. The core sample analyzed after alcoholic-extraction produced the best results for irradiated fresh ginseng samples. In the case of irradiated white and red ginseng samples, the central (natural) and radiation-induced (two-side peaks corresponding to cellulose radical) signal intensities showed little improvement on alcoholic-extraction. The water-washing step minimized the effect of Mn(2+), but reduced the intensity of side peaks making them difficult to indentify. The effect of different origins was negligible, however harvesting year showed a clear effect on radiation-induced ESR signals.
authors.affiliation: Department of Food Science & Technology, Kyungpook National University, Daegu 702-701, Korea.
authors.forename: Jae-Jun
authors.initials: JJ
authors.lastname: Ahn
authors.forename: Kashif
authors.initials: K
authors.lastname: Akram
authors.forename: Deokjo
authors.initials: D
authors.lastname: Jo
authors.forename: Joong-Ho
authors.initials: JH
authors.lastname: Kwon
keywords: Electron spin resonance; Identifi cation; Irradiation; Panax ginseng