  2001 AACC Annual Meeting Charlotte, North Carolina October 14-18, 2001 Charlotte Convention Center  |
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Physicochemical properties of mixed starch gels using waxy and non-waxy wheat. T. SASAKI (1), T. Yasui (1), and T. Satake (2). (1) National Agriculture Research Center; (2) Institute of Agricultural Engineering, University of Tsukuba, Ibaraki, Japan.
Mixed starches were prepared blending starches isolated from waxy and non-waxy wheat at various ratios. The amylose content of mixed starches ranged from 5 to 25%. The rheological properties of mixed starch gels were measured using a rheometer with a parallel plate geometry. Prepared starch gels (30% and 40%) were cooled and stored for 2 days. The change in storage modulus (G') was investigated and the rate constant of developing storage modulus was estimated by the first-order kinetic equation. The mixed starch gels with different amylose-amylopectin ratio had dramatically different properties. As the portion of waxy wheat starch increased, starch gels showed lower storage modulus. 40% mixed starch gel with more waxy starch showed rapid development of modulus during storage and higher rate constant of retrogradation. Mixed starch gel using waxy wheat was softer than non-waxy starch isolated from a single cultivar having the same amylose content as mixed starch. The results indicated that mixing starch isolated from waxy wheat produced weak gel and increased the retrogradation rate.
Copyright 2001
The American Association of Cereal Chemists