BREAKING CHAINS: A COMPARISON OF METHODS FOR THE PRODUCTION OF LOW- VISCOSITY DEXTRANS AND ALTERNAN

Authors: Cote, Gregory; Willett, Julious; Payne Wahl, Kathleen

Submitted to: Saccharides Symposium
Publication Type: Abstract Only
Publication Acceptance Date: 6/4/1997
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: Low-molecular-weight dextrans are used for such clinical applications
as blood plasma extenders and starting materials for dextran sulfates.
Related low-molecular weight glucans have been proposed as food
ingredients. Normally, dextrans are synthesized from sucrose as high- molecular weight polymers, which are unsuitable for many applications.
Strategies for producing materials of lower molecular size include acid
hydrolysis, enzymolysis, peroxide-catalyzed depolymerization,
ultrasonication, gamma-irradiation, and shear degradation. Synthesis
in the presence of acceptors (polymerization terminators) is also an
option. Each of these methods has its advantages and drawbacks. We
will compare some of these methods and their suitability for various
end-uses. Since our main interest is the cost-efficient production of
low-viscosity alternan and branched dextrans as bulk chemicals, we have
focused mainly on physical depolymerization methods. Our results
suggest that the most effective method on a laboratory scale is
ultrasonication, whereas twin-screw extrusion shows promise for larger- scale production. Properties of materials processed by both methods
will be described.