Functionality of chemically modified wild-type, partial waxy and waxy starches from tetraploid wheats

Authors

L. E. Hansen, USDA-ARS
David S. Jackson, University of Nebraska-LincolnFollow
R. L. Wehling, University of Nebraska-LincolnFollow
Robert A. Graybosch, University of Nebraska-LincolnFollow

Document Type

Article

Date of this Version

2010

Citation

Journal of Cereal Science 51 (2010) 409-414. DOI:10.1016/j.jcs.2010.02.010

Comments

Copyright © 2010 American Association of Cereal Chemists, Inc. Used by Permission.

Abstract

Partial waxy (reduced-amylose) and fully waxy (amylose-free) tetraploid durum 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 (Triticum aestivum L.). Purified starches were obtained from each genotype, and chemically modified by: 1) cross-linking with phosphorus oxychloride, 2) substitution with propylene oxide, and 3) sequential cross-linking with phosphorus oxychloride followed by substitution with propylene oxide. Functional properties were compared to blends of waxy and wild-type durum 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) typically were 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.