Amperometric Titration of Starch with Iodine

Part III. Titration of Various Starch-type Polysaccharides

抄録

Amperometric titration with iodine, a method devised by Kobayashi and Yoshida, was applied to various starch-type polysaccharides in order to elucidate the relation between the shape of titration curves and the structure of substances. Shapes of titration curves could be divided into 2 types, provisionally named the curves of amylose-type, and amylopectin-type, respectively.
Amyloses and linear dextrins with the degree of polymerization (DP) above 28 gave curves of the former type, which exhibited segments with more or less low gradient in the former half of the titration.
On the other hand, all of the branched polysaccharides, linear dextrins with DP below 25, Schardinger dextrins, and polyvinyl alcohol showed curves of the latter type, which rised linearly with added iodine.
The mode of interaction with iodine was discussed for these polysaccharides together with some observations on the starch-iodine coloration.