Abstract: In this work,Buckwheat Bran Polysaccharides (BBP) was extracted by water extraction and alcohol precipitation method.It was further purified by DEAE-52 cellulose column chromatography and Sephadex G-200.The molecular weight of the purified product was determined by gel filtration method,followed by the morphology characterization and component analysis using electron microscopy.The glycosidic bond configuration of the purified product was analyzed by infrared spectroscopy.The results showed that three polysaccharide fractions (BBP-I and BBP-II and BBP-III) were obtained by DEAE-52 cellulose column chromatography and Sephadex G-200 separation and purification and their molecular weights were 1.56×10⁴ Da,5.85×10⁴ Da,8.45×10⁴ Da,respectively.The electron microscopy showed that the surface of BBP was roughness and uneven.There was significant diversity about the appearance of the purified product,which mainly characterized by spherical,lamellar and rod,respectively.IR spectra demonstrated that BBP-I and BBP-III were alpha glycosidic bond compounds,while BBP-II was beta glycosidic bond compound.The differences of polysaccharide components in buckwheat bran would provide an important foundation for further structural research.

Key words: buckwheat bran polysaccharide, separation and purification, characterization