SDmatic: Measuring starch damage in flour - Chopin Technologies, France

Chopin Technologies, a subsidiary of KPM Analytics, is a French manufacturer of instruments for evaluating the quality of cereal, flour, and other related products. One of its most used instruments is the SDmatic, which can accurately determine starch damage in wheat flour.


Working principle of SDmatic

The SDmatic measures starch damage on flour based on the amperometric method (Medcalf & Gilles). The amperometric method basically involves measuring the iodine absorption in a diluted flour suspension. This is because 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 the ones that are not.

Determination of starch damage in flour using SDmatic

The SDmatic provides a simple, rapid, and accurate measurement of starch damage in flour. To begin the test, an acid solution is prepared with 1.5 grams of citric acid mixed with 3 grams of potassium iodide and 120 grams of water. 1 drop of sodium thiosulphate is added to this solution.This acid solution is the then added to the device reaction bowl.

Before introducing the flour to the acid solution, continuous rotation of the device’s electrode produces iodine from the acid solution. The device continuously measures the electric current that is proportional to the quantity of free iodine in the solution. Iodine has the property of rapidly binding with damaged starch granules. Once the flour is added to the solution, the iodine in the solution binds with the damaged starch granules of the flour added, thus causing reduction in number of iodine free ions. This directly results in lesser electric current being produced.The greater the reduction in current intensity, the greater the starch damage in the flour. Finally, the SDmatic displays the result as a percentage of the iodine absorbed or also in other international units.

Why measure starch damage?

During milling, starch granules are damaged to a level depending on the hardness of wheat, wheat preparation process, and mill settings. Once damaged, starch absorbs 10 times more liquid. Damaged starch affects the behavior of dough during mixing, giving it a sticky texture, which makes it difficult to handle for operators and machines. It also impacts the fermentation process,affecting the volume of baked goods and results in an undesirable output. All these reasons make it crucial to evaluate the extent of starch damage and ensure that it is within acceptable limits.

Applications of SDmatic


Starch damage in flour directly impacts the quality and volume of the baked goods produced. Hence, the SDmatic is commonly used in the milling industry to accurately evaluate the quality of flour.

Some of the important factors causing starch damage is the health of the milling instruments and the settings configured on the mill. By determining the extent of starch damage, the health of instruments being used and the mill settings can be scrutinised.


Starch damage adversely impacts the quality and volume of finished products in baking. Breads and cookies manufactured from starch damaged flour are undesirable because of their diminished color and cracks on the surface. The SDmatic is therefore employed by bakers to control the consistency of flour (hydration rate, proofing, behavior during the process) and thereby ensure quality of finished products.

SDmatic price

Agaram Industries is the official distributor of Chopin Technologies, who manufacture the SDmatic for starch damage determination. To get a quotation with the SDmatic price, you can fill up this form or send an email directly to

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