Characterization, antioxidant and hypoglycemic activities of degraded polysaccharides from blackcurrant (Ribes nigrum L.) fruits

Abstract

In this study, the degradation of polysaccharides from blackcurrant (BCP) was investigated. Two low-molecular-weight polysaccharides (DBCP-1, DBCP-2) were obtained using Fe²⁺ with different concentrations of H₂O₂ solution. IR spectra showed DBCPs had obvious characteristic peaks of polysaccharides. GC analysis confirmed DBCPs were composed of the same monosaccharide units as BCP but with different molar ratios. NMR analysis indicated DBCPs and BCP had similar glycosidic linkage patterns. The surface area of fragmented structure in DBCPs was reduced compared to BCP, and they had no triple helix structure. The results of bioactivity assays indicated that DBCPs exhibited higher antioxidant, α-amylase and α-glucosidase inhibitory activities than BCP, and the degraded polysaccharides with the lower molecular weight possessed higher bioactivities. These results suggested that Fe²⁺-H₂O₂ degradation did not change the main structure of polysaccharide and the degree of degradation could play a key role in the bioactivities of the polysaccharides.

Keywords: 1,1-Diphenyl-2-picrylhydrazyl radical (PubChem CID: 2735032); Acarbose (PubChem CID: 41774); Activities; Ascorbic acid (PubChem CID: 54670067); Blackcurrant; Characterization; Congo red (PubChem CID: 11313); Degradation; Dextran (PubChem CID: 4125253); Polysaccharides; Trichloroacetic acid (PubChem CID: 6421); d-Galacturonic Acid (PubChem CID: 439215); l-Arabinose (PubChem CID: 66308); p-Nitrophenyl-α-d-glucopyranoside (PubChem CID: 259380).