Electron paramagnetic resonance of gamma‐irradiated cellulose and lignocellulosic material

Publisher Website
Google Scholar
Abstract
Summary: The detection by electron paramagnetic resonance (EPR) spectroscopy of free radical centres trapped in cellulosic materials has been proposed as a potential method for the identification of irradiated foodstuffs of plant origin. However, the published spectra of irradiated cellulose show distinct differences from those obtained from unpurified cellulosic materials. In an attempt to explain these differences we have carried out a detailed investigation of the EPR spectra of gamma‐irradiated celluloses and of the products from a lignocellulosic material (oat straw) that had been subjected to various chemical treatments. We conclude that chemical treatments of cellulosic material involving strong alkali (15% in the present measurements) during purification result in subtle structural alterations which produce a different chemical environment for the unpaired electron that is trapped on irradiation.