The Characterization of Starch and Its Components. Part 3. The Technique of Semi‐Micro, Differential, Potentiometric, Iodine Titration, and the Factors Affecting It

An improved apparatus for the semi-micro, differential, potentiometric titration of starch and its components with iodine is described. The necessary experimental manipulations are given in detail. The factors affecting the measurement — the amount of dimethylsulphoxide present, the buffer concentration, the method of dissolving the starch, the defatting procedure used on the starch, and the temperature of measurement — are critically examined. The new technique results in values of iodine binding capacity for starches which are 5- 15% higher than previous measurements. The significance of this finding is discussed.