Influence of enrichment with ions from alkali (K), alkali-earth (Mg) and d transition (Cu, Fe)
metal groups of native and modified starches on the process of carbohydrate radicals
generation has been studied using electron paramagnetic resonance (EPR) spectroscopy.
This technique allows following the character and amount of created radicals, as well as the
changes in coordination sphere of transition metal ions incorporated into starch matrix. The
main difference between transition metal ions and the ions of alkali and alkali-earth metals
consisted in the character of their interactions with functional groups of starch. Transition
metal ions coordinated glucose units of starch and influenced the mechanism of carbohydrate
radical formation independently of the kind of starch modification. Interaction of starch, native
and modified, with ions of alkali and alkali-earth metals did not change the mechanism of
radical generation, however, influenced their number. Contents of total metal ions found
analytically by spectroscopic methods and by EPR allowed determination of the amount of
transition metal ions engaged in interactions with starch matrix, as well as the differentiating of
native and modified starch in respect of their metal ions adsorptive abilit.
keywords in English:
carbohydrate radicals, electron paramagnetic resonance, starch modifications, metal ions