Abstract:The polysaccharides from Nitraria sibirica Pall (NSP-C) fruit was prepared by enzymatic hydrolysis and purified using macroporous adsorption resin. The structure was preliminarily examined by gas-chromatography, liquid chromatography, infrared spectroscopy, scanning electron microscopy-energy dispersive X-ray spectroscopy, X-ray powder diffraction, Congo red staining, thermal analysis, periodate oxidation and the Smith degradation method; The functional properties of NSP-C were evaluated through measuring water- holding capacity, oil-holding capacity, emulsifying ability, emulsion-stabilizing ability, and free radical scavenging ability. NSP-C was composed of rhamnose, arabinose, mannose, glucose and galactose in a molar ratio of 1:1:0.73:2.04:3.75, and had a molecular weight of 5.07 ku. NSP-C had typical polysaccharide infrared absorption peaks, a triple helical structure and an amorphous structure, good thermal stability. NSP-C had good water-/oil-capacity (2.87 g/g and 5.97 g/g, respectively), and showed good emulsifying capacity under alkaline conditions (64.41 m2/g). The half maximal inhibitory concentrations of NSP-C against 2,2-diphenyl-1-picrylhydrazyl and hydroxyl free radicals were 0.209 and 0.149 mg/mL, respectively, indicating strong free radical scavenging ability. In summary, the NSP-C from the fruit of Nitraria sibirica has good functional properties and antioxidant activity, the experimental results can provide a scientific basis for the comprehensive utilization of Nitraria sibirica resources.
