The effect of autoclaving on the dispersibility and stability of three neutral polysaccharides in dilute aqueous solutions

• Published in: Carbohydrate polymers Vol. 45; no. 4; pp. 355 - 362
• Main Authors: Wang, Q, Wood, P.J, Cui, W, Ross-Murphy, S.B
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.08.2001; Elsevier Science
• Subjects: Agglomeration; Applied sciences; Autoclaving; Biodegradation; Dispersibility; Dispersions; Exact sciences and technology; Heat treatment; Molecular aggregation; Natural polymers; Physicochemistry of polymers; Polysaccharides; Pressure effects; Size exclusion chromatography; Solvents; Stability; Starch and polysaccharides; Thermal effects; Viscosity measurement; Water; Polysaccharides; Molecular aggregation; Stability; Autoclaving; Dispersibility; Solvent effect; Heat treatment; Experimental study; Dextran; Glucan; Mixed solvent; Natural gum; Solution structure; Concentration effect; Dilute solution; Specific viscosity; Oside polymer; Aqueous solution
• ISSN: 0144-8617; 1879-1344
• DOI: 10.1016/S0144-8617(00)00280-0

The dispersibility of three neutral polysaccharides, oat β-glucan, detarium xyloglucan and dextran in a dilute water–cadoxen mixture was studied by viscosity measurement. It was found that intrinsic viscosity measurement, with water–cadoxen mixtures as solvents, is a useful tool to distinguish polymer degradation from disruption of supramolecular aggregates. This approach, in conjunction with size exclusion chromatography, was used to study the effects of heat and pressure treatment on the dispersibility and stability of three polysaccharides in aqueous solutions. Autoclaving treatment at 121°C for 15 min may reduce the degree of aggregation. Following autoclaving in aqueous solution, the Huggins constants decreased from 0.66 to 0.42 for oat β-glucan and from 0.63 to 0.56 for detarium xyloglucan. It remains the same for dextran, indicating good solubility of this polymer in water. The current treatment did not cause evident changes in molecular weight and structures to detarium xyloglucan and dextran. However, degradation occurred with oat β-glucan. The Burchard–Stockmayer–Fixman approach was applied to estimate the unperturbed dimension of oat β-glucan and detarium xyloglucan on samples after autoclaving. The characteristic ratio C ∞ was found to be 7.3 for detarium xyloglucan and 4.7 for oat β-glucan, corresponding to the Kratky–Porod persistence lengths of 2.0 and 1.2 nm, respectively.