dc.contributor.author | Ballance, Simon | |
dc.date.accessioned | 2022-02-04T14:49:17Z | |
dc.date.available | 2022-02-04T14:49:17Z | |
dc.date.created | 2022-02-03T11:54:37Z | |
dc.date.issued | 2022 | |
dc.identifier.issn | 0268-005X | |
dc.identifier.uri | https://hdl.handle.net/11250/2977259 | |
dc.description.abstract | In an interlaboratory study we compare different methods to determine the weight-average molecular weight (Mw) and molecular weight distribution of six cereal beta-glucan isolates of nutritional importance. Size-exclusion chromatography (SEC) with multi-angle light scattering (MALS), capillary viscometry, sedimentation velocity analytical ultracentrifugation and one asymmetric flow field-flow fractionation (AF4)-MALS method all yielded similar Mw values for mostly individual chains of dissolved beta-glucan molecules. SEC with post-column calcofluor detection underestimated the Mw of beta-glucan >500 × 103 g/mol. The beta-glucan molecules analysed by these methods were primarily in a random coil conformation as evidenced from individual Mark-Houwink-Kuhn-Sakurada (MHKS) scaling coefficients between 0.5 and 0.6 and Wales-Van Holde ratios between 1.4 and 1.7. In contrast, a second AF4-MALS method yielded much larger Mw values for these same samples indicating the presence and detection of beta-glucan aggregates. Storage of the six beta-glucan solutions in the dark at 4 °C for 4 years revealed them to be stable. This suggests an absence of storage-induced irreversible aggregation phenomena or chain-scission. Shear forces in SEC and the viscometer capillary and hydrostatic pressure in analytical ultracentrifugation probably led to the reversable dissociation of beta-glucan aggregates into molecularly dissolved species. Thus, all these methods yield true weight-average molecular weight values not biased by the presence of aggregates as was the case in one of the AF4 based methods employed. | |
dc.language.iso | eng | |
dc.subject | Molar mass | |
dc.subject | Molar mass | |
dc.subject | Aggregates | |
dc.subject | Aggregates | |
dc.subject | Molekuler | |
dc.subject | Molecules | |
dc.subject | Lysspredning | |
dc.subject | Light scattering | |
dc.subject | Dietary fibre | |
dc.subject | Dietary fibre | |
dc.title | Inter-laboratory analysis of cereal beta-glucan extracts of nutritional importance: An evaluation of different methods for determining weight-average molecular weight and molecular weight distribution | |
dc.type | Peer reviewed | |
dc.type | Journal article | |
dc.description.version | publishedVersion | |
dc.source.volume | 127 | |
dc.source.journal | Food Hydrocolloids | |
dc.identifier.doi | 10.1016/j.foodhyd.2022.107510 | |
dc.identifier.cristin | 1997340 | |
dc.relation.project | Norges forskningsråd: 314599 | |
dc.relation.project | Nofima AS: 202101 | |
cristin.ispublished | true | |
cristin.fulltext | original | |
cristin.qualitycode | 1 | |