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Rheological behaviors of microbial polysaccharides with different substituents in aqueous solutions: Effects of concentration, temperature, inorganic salt and surfactant.
- Source :
-
Carbohydrate Polymers . Sep2019, Vol. 219, p162-171. 10p. - Publication Year :
- 2019
-
Abstract
- • Rheological behaviors of polysaccharides with different substituents have been studied. • Both the saccharide side chain and acetyl substituents improve the gelation of polysaccharide solutions at 25 °C. • The relationship between the apparent viscosity and concentration of GG conforms to the exponential equation. • The stability of gel structure containing longer saccharide side chains shows lower temperature/salt sensitivity. • Deacylated GG solutions transform into hydrogels in the presence of DTAB. Rheological behaviors of microbial polysaccharides with different substituents in aqueous solutions have been systematically investigated. Both the saccharide side chains and acetyl substituents improve the gelation of welan gum (WG), diutan gum (DG) and gellan gum (GG) in pure water at 25 °C. For the polysaccharides with saccharide side chains (WG and DG), the relationship between the apparent viscosity and concentration conforms to the linear equation, while that of the polysaccharide with acetyl (GG) is exponential. More importantly, the roles of substituents on the stability of the molecular conformation of polysaccharides are significantly depended on the surrounding environment. Disaccharide side chains promote the stability of helical conformation and gel aggregates of GG at high temperature (85 °C) or in the presence of inorganic salts with the ionic strength of 2.0 mol L−1. The stability of gel structure containing acetyl (GG) shows higher temperature/salt sensitivity. Additionally, deacylated gellan gum (GG(d)) solutions transform into hydrogels in the presence of dodecyltrimethylammonium bromide (DTAB). This study will help to obtain a better understanding on the rheological properties of polysaccharides with respect to the conformation and applications. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 01448617
- Volume :
- 219
- Database :
- Academic Search Index
- Journal :
- Carbohydrate Polymers
- Publication Type :
- Academic Journal
- Accession number :
- 136712741
- Full Text :
- https://doi.org/10.1016/j.carbpol.2019.05.032