Electron Paramagnetic Resonance as a tool for detection changes in the starch polymer occurring upon phosphorylation and high pressure treatment. A review.

Abstract: Modification by chemical and physical methods is widely used to improve features of the starch polymer important for industrial applications. In this review it was shown, that thermally generated radicals studied by Electron Paramagnetic Resonance (EPR) spectroscopy may serve as sensitive detectors of the changes occurring in the polymer structure and properties upon modification. Results obtained by using two types of radicals, relatively stable and short-lived ones, and two methods of modification, phosphorylation and high pressure treatment, were presented. Significance of the following experimental factors: optimal heating parameters, correctly prepared reference samples, sufficient amount of modifying agent, controlled moisture on the effectiveness of this method was evidenced. The proposed approach enables distinction between two types of phosphorus bonded as terminating or bridging polymer chains. Moreover, EPR data of the short-lived radicals reflect correctly the starch granule architecture and its changes caused by applied treatment.