The mechanism of thermal activated radical formation in potato starch studied by electron paramagnetic resonance and Raman spectroscopies.

Degradation of starch and the constituent fractions: amylopectin and amylose during thermal treatment in the range 423-503 K was investigated by electron paramagnetic resonance (EPR) and Raman spectroscopy. Degradation process was accompanied by the generation of carbon-centered stable radicals. EPR provided data on the nature and structure of radicals and on their evolution upon thermal treatment, whereas Raman spectroscopy allowed monitoring the changes of bonds in polysaccharides. It was found that amylose was the most susceptible toward high temperatures and the process of radical generation started at lower temperature than in amylopectin and starch, which were more resistant to thermal degradation.