Rheological characterizations of concentrated binary gum mixtures with xanthan gum and galactomannans

• Published in: International journal of biological macromolecules Vol. 114; pp. 263 - 269
• Main Authors: Jo, Wonjun, Bak, June Ha, Yoo, Byoungseung
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 15.07.2018
• Subjects: Galactomannans; Rheology; Synergistic effect; Thickener; Xanthan gum; Xanthan gum; Thickener; Synergistic effect; Rheology; Galactomannans
• ISSN: 0141-8130; 1879-0003
• DOI: 10.1016/j.ijbiomac.2018.03.105

The steady and dynamic shear rheological properties of binary gum mixtures with xanthan gum (XG) and galactomannans (guar gum (GG) and locust bean gum (LBG)) were examined in a concentrated solution (1% w/w) as a function of gum mixing ratio (100/0, 75/25, 50/50, and 0/100). All samples, except for individual GG and LBG, showed high shear-thinning behavior with yield stress. The values of flow (K, ηa,50, and σoc) and dynamic rheological parameters (G′ and G″) of XG-GG and XG-LBG mixtures were significantly higher compared to XG alone, indicating that the flow and viscoelastic properties of binary gum mixtures were greatly affected by the addition of GG and LBG. The maximum elasticity synergistic interaction for XG-galactomannans mixtures was observed at a mixing ratio of 50/50, showing a greatly positive deviation between measured and calculated values of G′. These results suggest that the synergistic effect of GG and LBG addition on rheological properties of XG appears to be due to intermolecular interaction occurred between XG and galactomannans, as confirmed by dynamic rheological properties. •Effect of gum mixing ratio on rheological properties of binary gum mixtures were examined.•A maximum synergy for XG-GMs mixtures was observed at a 50/50 mixing ratio.•The molecular interaction between XG and LBG was much stronger when compared to XG-GG.•A small addition of GMs to XG was more efficient in terms of improving a safe and easy swallowing.•Rheological results can be useful in designing new XG-based food thickeners for patients with dysphagia.