Rheological and Micro-Rheological Properties of Chicory Inulin Gels

Abstract

As a soluble fiber, inulin is present in many plants and has many applications in food and non-food products. In this work, we investigated the rheological properties of inulin dispersions at seven concentrations. The linear viscoelastic properties of inulin were determined using a conventional mechanical rheometer. At 25 wt%, inulin exhibited fluid-like viscoelastic liquid behavior. However, when concentrations were ≥27.5 wt%, inulin exhibited gel-like viscoelastic properties. The viscoelastic properties (moduli and viscosities) increased with increasing inulin concentration. The high-frequency linear rheological properties of inulin were also investigated using the modern light scattering technique, diffusion wave spectroscopy (DWS). The diffusion wave spectroscopy (DWS) measurements showed the amplitude of complex moduli (|G*(ω)|) of inulin gels (≥27.5 wt%) to be proportional to ½ power law of the frequency, which suggests inulin gels behave similarly to flexible polymers. The non-linear steady shear experiments demonstrated that inulin exhibited shear-thinning behavior that was well fitted by a power law constitutive model. The trend of the power law exponent from the experiments indicated that the shear-thinning extent for inulin was greater as the inulin concentration increased. The results of this work indicated that the properties of inulin gel can be manipulated by altering its concentration. Therefore, the desired inulin product can be designed accordingly. These results can be used to direct further food and non-food applications, such as wound healing materials for inulin gels.

Progress in the Preparation and Application of Inulin-Based Hydrogels

“…Furthermore, these inulin hydrogels can undergo chemical modifications to boost their drug delivery effectiveness, making them suitable scaffolds for various drug delivery applications [ 84 ]. In comparison to other polysaccharide-based hydrogels, inulin-based hydrogels typically exhibit shear-thinning properties, which renders them advantageous for further application as injectable and oral administration drug delivery systems [ 58 , 59 , 85 , 86 , 87 , 88 ]. Additionally, inulin’s capability for enzymatic degradation specifically in the colon enhances its utility for colon-targeted drug delivery.…”