Improvement of antioxidant activity of chitosan by chemical treatment and ionizing radiation

Effect of γ-irradiation on structure and nutraceutical potential of β-d-glucan from barley (Hordeum vulgare)

“…Irradiation of ␤-glucan results in increase of solubility [13], and thus the metal chelating effect. Similar increase in metal chelating ability, as a result of irradiation, has been reported in polysaccharide such as chitosan [39]. …”

“…The carbonyl groups might be produced by breaking the glycosidic bond in ␤-d-glucan by the hydroxyl radicals generated by gamma irradiation. Similar increase in inhibition of lipid peroxidation, as a result of irradiation has been reported in polysaccharides such as laminarin [48] and chitosan and its derivatives [39]. This antioxidant capacity may also be linked to the presence of free -OH groups in this polysaccharide.…”

“…Irradiated ␤-d-glucan has already been reported as an immune enhancing polysaccharide both in vivo The increased scavenging activity of ␤-d-glucan might be due to the breakdown and depolymerization of the polysaccharide by radiolysis to low molecular weight subunits that leads to the exposure of their hydroxyl groups and decreasing the intramolecular hydrogen bonding [38]. This result was well supported by the reports related with the depolymerization of polysaccharides by irradiation on tamarind seed polysaccharide (TSP) from Tamarindus indica L. [28] and chitosan and its derivatives [39]. Recently, Heidarieh et al [40] reported that the ergosan showed the increased DPPH radical-scavenging activity by the gamma irradiation.…”

Effect of γ -irradiation on antioxidant and antiproliferative properties of oat β -glucan

“…Also, the scavenging activity of chitosan, a naturally occurring cationic polysaccharide and its derivatives increased with irradiation treatment. Inverse relationship was found between DPPH radical scavenging effect (%) and molecular weight of chitosan (Abd El-Rehim et al, 2012).…”

Tailoring the properties of chitosan-poly(acrylic acid) based hydrogels by hydrophobic monomer incorporation

“…1b)) of modified Cs at 1618 cm À 1 and 1703 cm À 1 , corresponding to vinyl and carboxyl groups, respectively [15]. The polymerization of synthetic monomers in the presence of functionalized Cs and network formation was confirmed by the disappearance of the characteristic peak attributed to vinyl group.…”