Thermal decay processes of organic free radicals in γ-ray irradiated cellulose rich foodstuffs

Abstract

Using electron spin resonance (ESR) spectroscopy, we revealed the thermal decay processes of radicals as induced by γ-irradiation on cellulose rich foodstuffs. Upon the irradiation, the satellite signals were newly generated at the symmetric positions of the organic free radical, i.e., the g=2.0 signal. By heat treatment, the satellite signals decayed exponentially to the heating duration. The ESR signal of the irradiated food heated for more than 10 min was essentially the same as that before the irradiation. In order to evaluate the radical decay processes during heating, we defined a time-dependent master equation. Based upon the general solution of the master equation, we evaluated the time constant of the radical decay by the nonlinear least squares method.