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United States Department of Agriculture

Agricultural Research Service

Title: Characterization of a Novel Modified Alternan

Authors
item Leathers, Timothy
item Nunnally, Melinda
item Ahlgren, Jeffrey
item Cote, Gregory

Submitted to: Society of Industrial Microbiology Annual Meeting
Publication Type: Abstract Only
Publication Acceptance Date: August 14, 2003
Publication Date: August 14, 2003
Citation: Leathers, T.D., Nunnally, M.S., Ahlgren, J.A., Cote, G.L. 2003. Characterization of a novel modified alternan [abstract]. Society of Industrial Microbiology. p. 100.

Technical Abstract: Alternan is a glucan with a unique backbone structure of alternating alpha-(1-6) and alpha-(1-3) linkages. Recently, novel strains of Penicillium sp. were isolated that quantitatively modify alternan to lower apparent molecular weight forms with solution viscosity properties that resemble those of gum arabic (U. S. Patent 6,479,275). Gum arabic is exclusively imported, and it would be desirable to have a domestic alternative of consistent quality and price. Modified alternan was further characterized to evaluate its potential for commercial applications. High molecular weight native alternan was progressively modified to lower molecular weight heterodisperse forms, associated with a reduction in absorbance at 225 nm, light scattering, and opalescence. Modified alternan exhibits a linkage pattern generally similar to that of native alternan. The solution viscosity properties of modified alternan resemble those of ultrasonicated alternan and commercial gum arabic, although alternan lacks the emulsification capacity of gum arabic. Alternan solutions are extremely stable at 4-37°C and at pH 3-9. Dry preparations of alternan are bright white powders that are not highly hygroscopic. Thus, modified alternan is promising for further development as a gum arabic substitute.

Last Modified: 8/22/2014
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