The effects of NaCl and CaCl2 (0-200 mM) on the rheological properties of Plantago lanceolata seed mucilage (PLSM) as a novel potential source of polysaccharide gum were investigated in this study. Furthermore, FTIR analysis was measured to supply more structural information. The FTIR spectra revealed that PLSM with the presence of glycoside bonds and carboxyl and hydroxyl groups behave like a typical polyelectrolyte. It was observed that the gum solutions exhibited viscoelastic properties under the given conditions and the addition of salts had significant affection on the rheological parameters of gum solutions. The weak gel-like behavior (0.1 < tan δ < 1) observed for all solutions at different ion types and ionic strengths. The limiting values of strain mostly increased with enhance cation concentration due to the intermolecular interaction and therefore increase the stiffness of gum solutions in the concentrated domain. The frequency sweep results showed that developing ion concentration had a positive effect on the viscoelasticity of gum solutions which Ca2+ was more effective than Na+. Tanglertpaibul&Rao model showed the highest efficiency to evaluate the intrinsic viscosity of PLSM for all co-solutes. The results of this study could be useful when considering the effects of salts on food systems.
Keywords: Plantago lanceolata seed mucilage; Rheology; Salt.
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