Periodate oxidation of plant polysaccharides provides polysaccharide-specific oligosaccharides

Abstract

Although polysaccharides are frequently used in foods, detailed characterization and/or identification of their structures using a single method remains a challenge. We investigated the suitability of periodate oxidation as an approach to depolymerize polysaccharides, allowing characterization and/or identification of the original polysaccharides based on ESI-MS analyses of the released oligosaccharides. Various periodate oxidation conditions were tested on (arabino)xylan, galactomannan, xyloglucan and homogalacturonan. Each polysaccharide required a different oxidation condition to release a substantial level of oligosaccharides. These oligosaccharides had highly complex structures due to the presence of e.g., dialdehyde sugars, hemialdals, and remnants of (oxidized) sugars, as verified by ESI-MS/MS. Despite these oligosaccharides were highly complex and lost some polysaccharide structural features, each periodate-oxidized sample comprised polysaccharide structure-dependent MS oxidized oligosaccharide profiles. Our findings are a good starting point to find a more generic chemical polysaccharide depolymerization approach based on periodate oxidation to identify polysaccharides by oligosaccharides fingerprinting using MS.

Keywords: Depolymerization; Oxidized oligosaccharide clusters; Periodate oxidation; Plant polysaccharides.