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United States Department of Agriculture

Agricultural Research Service

Research Project: GENETIC IMPROVEMENT AND EVALUATION OF HARD WINTER AND SPRING WHEATS

Location: Grain, Forage & Bioenergy Research

Title: Functionality of Chemically Modified Wild-Type, Partial Waxy and Waxy Starches from Tetraploid Wheats

Authors
item Hansen, Lavern
item Jackson, D -
item Wehling, R -
item Graybosch, Robert

Submitted to: Journal of Cereal Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: February 10, 2010
Publication Date: April 2, 2010
Repository URL: http://hdl.handle.net/10113/42027
Citation: Hansen, L.E., Jackson, D.S., Wehling, R.L., Graybosch, R.A. 2010. Functionality of Chemically Modified Wild-Type, Partial Waxy and Waxy Starches from Tetraploid Wheats. Journal of Cereal Science. Volume 51: 409-414.

Interpretive Summary: Wheats with “waxy” or amylose-free starch have been developed. The starch of such wheats possesses altered cooking properties. Waxy maize starch is a staple of the U.S. starch industry, and is most commonly used in the production of modified food starches. Experiments demonstrated that waxy wheat starch may be chemically modified to achieve similar functional properties to those of modified waxy maize starch. In addition, either through use of genetically-controlled “partial waxy” (reduced amylose) lines, or via the blending of waxy and normal (wild-type) wheats, food processors could develop starches with a wide range of functional properties. Waxy wheat starch would present U.S. gluten protein manufacturers with a unique starch product, which, coupled with the extraction of vital gluten, (not found in maize) would present a unique product combination.

Technical Abstract: Partial waxy (reduced-amylose) and fully waxy (amylose-free) tetraploid wheats (Triticum turgidum L. var durum) were developed by introgression of null alleles at the Wx-A1 and Wx-B1 loci from common hexaploid wheat (T. aestivum L.). Purified starches were obtained from each genotype, and chemically modified by: 1) cross-linking with phosphorus (V) oxychloride, 2) substitution with propylene oxide, and 3) sequential cross-linking with phosphorus (V) oxychloride followed by substitution with propylene oxide. Functional properties were compared to blends of tetraploid waxy and wild-type starches of known amylose contents. Significant differences in functionality were observed amongst the genotypes and blends after each modification. Waxy (0% amylose) and wild-type (30% amylose) were very often at the extremes of the observed ranges of functional properties. In general, the functional properties of the chemically modified starches were dependent upon amylose content. Starches from Wx-B1 null lines (24% amylose), were an exception. After substitution, such starches had the significantly highest value for RVA final viscosity, and generally performed in a manner similar to starch blends of 12-18% amylose.

Last Modified: 4/18/2014
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