Cereal Chem 42:546 - 557.  |  VIEW ARTICLE

Determination of Starch Damage by Rate of Iodine Absorption.

D. G. Medcalf and K. A. Gilles. Copyright 1965 by the American Association of Cereal Chemists, Inc. 

The rate of iodine absorption by a starch suspension depends on the characteristics of the granules. Damaged granules absorb iodine at a faster rate than do undamaged ones. A convenient means to measure this absorption is by amperometric titration. A method is proposed to use this technique for quantitative determination of damaged starch in flour. Reagents and equipment requirements are simple, only 0.2-g. samples are needed, and the time for each determination is approximately 15 min. A linear response was obtained for starch damages ranging from very high to very low. Starch damage determinations were performed on a series of flour samples using the proposed amperometric method, two enzymatic methods, and a colorimetric method. The proposed technique gave results comparable to these published procedures for starch damage values below 10%. Above 10% starch damage, the amperometric method gave higher values. It is suggested that the amperometric method may give a more accurate indication of starch damage when the amount of damage is relatively large, such as in air-classified fractions.