Differences in physicochemical, rheological, and prebiotic properties of inulin isolated from five botanical sources and their potential applications

Abstract

This study compares the physicochemical and prebiotic properties of inulin isolated from five botanical sources. The average degree of polymerization (DP) for inulin ranged from 5.00 to 13.33. Notably, inulin from Dahlia tubers (DP = 13) and Platycodonis Radix (DP = 8) demonstrated granular, clustered morphology under SEM, semi-crystalline structures via X-ray diffraction, and exhibited shear-thinning behaviors from shear rate 1 s−1 to 500 s−1. In contrast, inulin from Jerusalem artichoke (DP = 5), chicory root (DP = 7), and Asparagi Radix (DP = 5) showcased rough flake morphologies under SEM, amorphous structures in X-ray patterns, and similar shear-thinning behaviors. All inulin types showed acid stability at pH levels below 2.0, with a reducing sugar conversion ratio (RRS) under 1 %. Furthermore, the isolated inulin from the different sources presented prebiotic capacity when added as a sole carbon source in the culture media of the probiotics Lactobacillus paracasei and Bifidobacterium longum. This study provides the properties of inulin from various sources, thereby offering a reference for the selection of appropriate inulin in industrial applications based on the desired characteristics of the final product.