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Updated: Sep 28, 2025

Molecular Entanglement and Electrospinnability of Biopolymers
Published on: September 3, 2014
Chain conformations and steady-shear viscosity properties of pectic polysaccharides from apple and tomato
Shihao Hu1, Junqiao Wang2, Shaoping Nie2
1College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, China.
Abstract:
In this study, apple pectin (AP) and tomato pectin (TP) were demonstrated to be a high-ester (74.8%) polysaccharide with the weight-average molecular weight (M ) of ∼ 243 kDa and a low-ester (45.9%) polysaccharide with the M of ∼ 19 kDa, respectively. The semi-rigid chain conformations of pectic polysaccharides in NaNO3 aqueous solution were deduced according to the Smidsrød "B values" of AP (0.025) and TP (0.029), while AP and TP exhibited higher stiffness in water due to the electric repulsion of carboxyl groups, which was visually observed by AFM images. Under steady shear, the shear-thickening behaviors of AP and TP in NaNO3 aqueous solutions were observed in the shear rate range of < 1 s-1, which were attributed to the disruption of the ordered arrangement induced by semi-rigid pectin chains into randomly entangled structure by weak shear force. AP exhibited stronger shear-thickening behavior due to the formation of more entanglements resulted from the higher M and longer side chains highly branched at rhamngalacturonan region. This study provides the scientific basis for the construction of the relationship of steady-shear property with chain conformation and molecular weight of pectin.
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