Influence of copper catalyst on the mechanism of carbohydrate radicals generation in oxidized potato starch

The effects of short-term selenium stress on Polish and Finnish wheat seedlings—EPR, enzymatic and fluorescence studies

“…They were similar, for example, to those reported in the literature for deoxyribose radicals in photo-excitated DNA nucleosides and their derivatives (Adhikary et al, 2006). Analysis of the values of HFS parameters for other carbohydrate systems (Madden and Bernhard, 1982;Kuzuya et al, 1999;Łabanowska et al, 2011) led to similar conclusions, that the hyperfine structure of signals from the first group could be caused by the interaction of an unpaired electron localized at the carbon atom with nuclear magnetic moment of ␤ or ␣ hydrogen. Hence, signals I and V were attributed to radicals formed, for example, by the abstraction of hydrogen from the C(1) carbon atom in the glucose unit of different carbohydrates.…”

“…It is known that stable long lived radicals are generated easily in mono and polysaccharides (Madden and Bernhard, 1982;Kuzuya et al, 1999;Łabanowska et al, 2011). Taking into account that many kinds of saccharides are present in plant tissues, we considered the attribution of particular signals, in raw and lyophilized leaves, to sugar radicals with an unpaired electron localized at carbon atom.…”

Determination of free radicals and flavan-3-ols content in fermented and unfermented teas and properties of their infusions

“…The values of its HFS splitting were significantly higher than those observed for signals of semiquinone radicals [26]; hence, we ascribed tentatively signal III to carbohydrate radical. The formation of such centre could occur under the influence of solar, mechanical, irradiation or thermal energy and was observed in living plants, as well as in other biological materials subjected to c-irradiation, heating or grinding [27][28][29][30][31] Fig. 1 The experimental (exp) and simulated (sim) EPR spectra of different kinds of teas, registered at 293 K, at 3 mW, in the range 5 mT and their particular signal components (I, II, III, IV) used to simulation of the spectra: a Teekane black, b Lipton black, c Lipton green, d Bio-Active green, e Yunnan white I, II-signals of semiquinone radicals, III-carbohydrate radical localised at C(1) atom of glucose, IV-carbohydrate radical localised at C(1) atom of glucose unit in oligosaccharide structure created after dehydration b probably mono or disaccharides [31][32][33].…”

“…The signal IV exhibited a significantly higher intensity in unfermented white and green teas, which might indicate that it was linked with the paramagnetic centre which decayed in the course of the fermentation process. A relatively high value of its g-factor could suggest that the signal originated from a carbohydrate radical, localised probably in polysaccharides structure [27,28,30,34,35]. The absence of HF lines pointed to the lack of interactions between magnetic moments of an unpaired electron and hydrogen nuclei, which was probably caused by the removal of hydrogen atoms from polysaccharide molecule, for example upon dehydration process, which occurred during drying.…”

Effect of Complexation of Starches Oxidised With Mineral Elements on Their Rheological Properties

“…Jednak dzięki specyficznej budowie, łatwo ulegają reakcjom z substancjami chemicznymi, w wyniku których powstają skrobie modyfikowane o pożądanych właściwościach fizykochemicznych i reologicznych [22]. Ponadto skrobia, ze względu na obecność w swojej strukturze grup hydroksylowych, a dodatkowo w skrobi utlenionej grup karbonylowych i karboksylowych, przejawia skłonność do przyłączania jonów metali [2,3,5,11,13]. Istnieje więc możliwość wykorzystania skrobi jako nośnika mikro-i makroelementów dla organizmu człowieka.…”