Cereal Chem 54:138 - 149. | VIEW
Characterization and Comparison of Cereal Starches.
C.-Y. Lii and D. R. Lineback. Copyright 1977 by the American Association of Cereal Chemists, Inc.
Starches were isolated from hard wheat (two varieties), soft wheat, club wheat, durum wheat, tritical, rye, and Triticum dicoccum (Emmer). All starches lost birefringence within the range 50.0 to 64.5 C. Scanning electron microscopy revealed similar granule sizes and shapes for all starches, except rye. Iodine affinites of the starches ranged from 4.36 to 4.91%. Brabender amylograms obtained for each starch were characteristic of normal cereal starches. When amylopectin fractions isolated from each starch were debranched with isoamylase and subjected to gel filtration through Bio-Gel P-10, two chain populations of carbohydrate with d.p. of approximately 11-25 and 52-60 were obtained from each amylopectin. Average unit-chain lengths of the amylopectins ranged from 15 for triticale to 26 for rye. The ratio of A-chains to B-chains in each amylopectin, determined enzymatically using phi, beta-dextrins, and beta-limit dextrins, ranged from 1.21 to 2.11. The amylose fractions isolated from each starch had beta-amylolysis limits ranging from 76.6 to 81.6%. The wheat starches investigated appeared to have definite, but minor, differences in structure.