The Falling Number® System measures the alpha-amylase enzyme activity in grains and flour to detect sprout damage, optimise flour enzyme activity and guarantee soundness of traded grain. Alpha-amylase activity is crucial for final product quality of bread, pasta, noodles and malt. Anyone handling wheat, barley, rye or sorghum intended for these applications will benefit from the Falling Number system.
The method is standardized by international bodies such as the ICC, AACCI, ISO and ASBC in the standards:
ICC/No. 107/1 (1968)
AACCI/No. 56-81.03 (1972)
ISO/No. ISO/DIS 3093 (1974)
ASBC Barley 12-A
Under conditions of prolonged dampness or rain, grain kernels may start to germinate, or sprout, when the crop is still standing. Germination begins when kernels absorb water and generate enzymes that break down stored starch and protein in the endosperm. The enzymes release sugars from starch and amino acids from proteins which nourish the growing embryo.
Alpha-amylase is one of the enzymes produced in the sprouting kernel. Although some alpha-amylase enzyme is present in the embryo or germ of sound wheat kernels, when germination begins the embryo and layers surrounding the starchy endosperm produce the enzyme at an accelerating rate. A severely sprout-damaged kernel contains many thousands of times the amounts of enzyme present in kernels that are in the early stages of germination. Because of this, a wheat sample containing very low levels of severely sprouted kernels may exhibit significant amylase activity. Alpha-amylase converts starch into sugars in the sprouting kernel, and similarly breaks down the starch granules in wheat flour when mixed with water to make bread dough.The Falling Number Method
When the tubes are placed in the boiling water bath, the starch begins to gelatinize and the slurry becomes more viscous. The mixing makes sure the gelatinization is homogeneous in the slurry. What also happens at this elevated temperature is that the alpha-amylase enzyme starts to break down the starch and the viscosity thus decreases. The amount of starch break-down is dependent on the alpha-amylase activity and this means that the higher the activity of the alpha-amylase the lower the viscosity will be. When the stirrer is dropped, its speed and thus the time it takes it to fall to the bottom, will be determined by the viscosity of the slurry.
In other words, the more sprouted the grain was the higher the alpha-amylase activity will be. The higher the alpha-amylase activity the lower the viscosity of the slurry. The lower the viscosity of the slurry the faster the stirrer will fall to the bottom. That is why more sprouted grain results in a lower Falling Number as Falling Number is the time it takes the stirrer to fall to the bottom.