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United States Department of Agriculture

Agricultural Research Service

Title: Capillary Electrophoresis of Plant Starches As the Iodine Complexes

Authors
item Brewster, Jeffrey
item Fishman, Marshall

Submitted to: Journal of Chromatography
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: November 15, 1994
Publication Date: N/A
Full Text Available

Interpretive Summary: Much research is currently focused on the use of plant starch as an industrial raw material to reduce dependence on non-renewable resources and to provide new, high-value markets for agricultural products. Discovery and development of new starch-based products requires effective methods for analysis and characterization of starch and starch derivatives. Most modern analytical methods are not suitable for starch analysis due to the very high molecular weight of starch. We have devised new methodology which permits the analysis of starch and related carbohydrates in minutes, rather than hours. Starch is mixed with an iodine solution, forming a charged strongly colored complex. Each of the starch components binds differing amounts of iodine, resulting in differences in charge/mass ratio which enables them to be separated by electrophoresis and detected optically. Analyses can be readily automated using commercial capillary electrophoresis instruments. This methodology will give starch researchers, manufacturers, and users a powerful tool for characterization and quality control of this and other structually- related biopolymers.

Technical Abstract: Much research is currently focused on the use of plant starch as an industrial raw material which can reduce dependence on non-renewable resources. Development of new starch-based products requires effective methods for analysis and characterization of starch and related biopolymers. Most separation methods are not suitable for this application due to the high molecular weight (>10(6)) of starch. We describe here the use of iodine complexation to impart charge and permit detection of starch components by capillary electrophoresis. Amylopectin and amylose were resolved in less than 10 minutes using iodine-containing buffers in unmodified capillaries. Partial resolution of an oligosaccharide mixture was also demonstrated, indicating potential utility of the method for analysis of smaller biopolymers. The primary basis for starch separation was shown to be iodine binding affinity, which can be manipulated through control of both temperature and iodine concentration.

Last Modified: 12/19/2014
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