CEREAL-GRAINS - A STUDY OF THEIR ALPHA-1,4-ALPHA-1,6 GLUCOPOLYSACCHARIDE COMPOSITION

The glucopolysaccharides containing α‐1,4 and α‐1,6 linkages present in the endosperm of mature cereal seeds (corn, wheat and rice) were fractionated according to their branching degree. An already published method [19] was used to specifically estimate the α‐1,6 linked glucoses involved in the branching points. The following features were found: a) Starches from different tissues vary in their relative amount of amylose and amylopectin. b) Amylose is present either as a strictly linear or additionally as a lowly branched polysaccharide. c) Amylopectins with a rather wide range of branching degrees were detected. A redefinition of the starch α‐1,4—α‐1,6 glucopolysaccharides based on their λmax and percentages of glucoses in branching points was introduced. A linear correspondence between brauching points and the maximum absorption (λmax) in the presence of Krisman's iodine reagent was obtained. Copyright © 1990 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim