Thermally generated radicals as indicators of the starch modification studied by EPR spectroscopy: a review.

The results compiled and discussed in the present review have been published by the research group of the Chemistry Faculty, Jagiellonian University or by other Authors, as given in References. Relatively stable and short-lived radicals generated thermally in starches of various botanic origin were used as indicators of the changes in the starch structure and properties occurring upon chemical and physical modifications. The number of radicals was determined by electron paramagnetic resonance (EPR) spectroscopy. Distribution of water and accessibility of different zones in the starch granule for reagents were tested by using paramagnetic Cu(2+) ions as a probe molecule. Relatively stable radicals generated in starch at 300°C revealed protective properties against ionizing radiation. Thermally induced short-lived radicals exhibited sensitivity to the degree of the starch structure ordering.