Preparation, deproteinization, characterization, and antioxidant activity of polysaccharide from Medemia argun fruit

In this study, the crude polysaccharide from argun palm (Medemia argun) fruit was extracted with hot water and deproteinized by four different methods. Its structure characterization, thermal property and antioxidant activity were investigated by FT-IR spectroscopy, Scanning electron microscope, Congo-red, I2-KI, DPPH• assay, ABTS•+ assay, TGA and DSC analysis. It indicated that the NaCl method was the best method in deproteinization. The argun fruit polysaccharide linked by the β-glycosidic bonds. The molecular weight of polysaccharide deproteinized with NaCl was 4.46 × 105 Da. It showed that the polysaccharide from argun palm fruit consisted of fructose, arabinose, rhamnose, galactose, glucose, xylose, and galacturonic acid. The result of TGA and DSC assay indicated that argun fruit polysaccharide has a favorable thermal stability. It was proved that, the argun fruit polysaccharide possessed high antioxidant activity and would be a new natural antioxidant.