Characterisation of the molecular properties of scleroglucan as an alternative rigid rod molecule to xanthan gum for oropharyngeal dysphagia

Research output: Contribution to journalArticlepeer-review

Authors

  • Xinxin Li
  • Yudong Lu
  • Gary Adams
  • Hanne Zobel
  • Simon Balance
  • Stephen Harding

Colleges, School and Institutes

External organisations

  • Kulturhistorisk Museum, Universitetet i Oslo
  • School of Biosciences, University of Nottingham
  • Nofima AS, Norwegian Institute of Food, Fisheries and Aquaculture Research
  • University of Nottingham

Abstract

Scleroglucan, a neutral β(1-3) glucan with β(1-6) glucan branches every third residue, is being considered as an alternative rod-like, shear thinning high molecular weight β-glucan based polysaccharide to xanthan gum for the management of patients with oropharyngeal dysphagia. It is therefore important to understand more fully its hydrodynamic properties in solution, in particular heterogeneity, molecular weight distribution and its behaviour in the presence of mucin glycoproteins. A commercially purified scleroglucan preparation produced by fermentation of the filamentous fungus Sclerotium rolfsii was analysed in deionised distilled water with 0.02% added azide. Sedimentation velocity in the analytical ultracentrifuge showed the scleroglucan preparation to be unimodal at concentrations > 0.75 mg/ml which resolved into two components at lower concentration and with partial reversibility between the components. Sedimentation coefficient versus concentration plots showed significant hydrodynamic non-ideality. Self-association behaviour was confirmed by sedimentation equilibrium experiments with molecular weights between ~3x106 g/mol to ~5x106 g/mol after correcting for thermodynamic non-ideality. SEC-MALS-viscosity experiments showed a transition between a rod-shape at lower molar masses to a more flexible structure at higher masses consistent with previous observations. Sedimentation velocity experiments also showed no evidence for potentially problematic interactions with submaxillary mucin.

Details

Original languageEnglish
Article number105446
JournalFood Hydrocolloids
Volume101
Early online date16 Oct 2019
Publication statusPublished - Apr 2020