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A New Electron Paramagnetic Resonance Method to Identify Irradiated Soybean
Author(s) -
Sanyal Bhaskar,
Sharma Arun
Publication year - 2009
Publication title -
journal of food science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.772
H-Index - 150
eISSN - 1750-3841
pISSN - 0022-1147
DOI - 10.1111/j.1750-3841.2009.01314.x
Subject(s) - electron paramagnetic resonance , irradiation , nuclear magnetic resonance , electron paramagnetic resonance spectroscopy , food irradiation , chemistry , materials science , physics , nuclear physics
Low‐dose gamma irradiation causes minimal changes in food matrix making identification of radiation‐processed foods a challenging task. In the present study, soybean samples were irradiated with commercially permitted gamma radiation dose in the 0.25 to 1.0 kGy range for insect disinfestations of food. Immediately after irradiation electron paramagnetic resonance (EPR) spectrum of the skin part of soybean showed a triplet signal ( g = 2.0046, hyperfine coupling constant hfcc = 3.0 mT) superimposed on naturally present singlet. These signals were characterized as cellulose and phenoxyl radicals using EPR spectrum simulation technique. Kernel part of the samples exhibited a short‐lived, radiation‐induced singlet of carbon‐centered radical superimposed on naturally present sextet signal of Mn 2+ . A detailed study on relaxation and thermal behavior of induced radicals in skin part was carried out using EPR spectroscopy. These findings revealed that progressive saturation and thermal characteristics of the induced radicals may be the most suitable parameters to distinguish soybean subjected to radiation dose as low as 0.25 kGy from thermally treated and nonirradiated samples, even after a prolonged period of storage.