The Characterization of Starch and Its Components. Part 6. A Critical Comparison of the Estimation of Amylose-Content by Colorimetric Determination and Potentiometric Titration of the Iodine-Complex

This paper is dedicated to Mr. Ernst Hees, Editor of „Die Stärke”︁ from 1958 until December, 1973, as a token of the esteem with which we regard his work in this capacity. We thank him for his efforts, which have so successfully helped to advance the subject of starch chemistry in all its diverse aspects. The techniques of (i) semi-micro, differential, potentiometric iodine titration of starch with iodine, and (ii) colorimetric assay of the starch-iodine complex in solution have been compared as analytical tools for the measurement of the amylose-content of starches. Although the colorimetric method may be calibrated to give comparable results to the potentiometric assay, the former technique is not applicable to maize starches of high amylose-content.