Extraction, purification, structural characterization, and antioxidant activity of polysaccharides from Wheat Bran

Abstract Wheat bran is a major by-product of wheat processing, but the structural characterization and antioxidant activity of the polysaccharide are not clear. The manuscript aimed to preliminarily investigate the physicochemical properties, glycoside linkages and antioxidant activity of wheat bran polysaccharide. In the present study, one novel polysaccharide (WBP) was extracted by hot water method, isolated and purified by Sephadex G-100 chromatography. The physiochemical properties and structure were primarily analyzed by HPLC chromatography, FT-IR spectrum, NMR spectra, SEM, monosaccharide composition and methylation. The results revealed that WBP (Mw = 2.99 ×  105 Da) was mainly consisted of arabinose, xylose, mannose, glucose, and galactose in the ratio of 5.90: 6.25: 1.00: 2.06: 4.74. In addition, wheat bran polysaccharides exhibited remarkable antioxidant activities according to DPPH, ABTS, hydroxyl and superoxide radical scavenging tests. The manuscript provides theoretical basis for the utilization of wheat bran in functional food or medicine industries.