How does it work?
The FN test details the effect of the α-amylase on the starch granules in the flour undergoing gelatinization, and progressively broken down (cleaved) by the amylase action.1 The temperature set for the test provides maximum enzymatic activity in the flour/water mixture or suspension.
The FN is the time in seconds required for a device to fall a measured distance through a hot flour/water mixture while heat is applied. If the enzymatic activity is high, the starch is broken down (liquefied) rapidly during gelatinization. So then, the device falls through the relatively liquid paste in a short time. A less viscous fluid opposing less resistance to the flow means the FN is low. On the other hand, if the activity of the enzyme is low, it takes longer for the device to cover the distance of its fall. This means the falling number is high.2
Falling numbers over 250 seconds are most suitable for the bread-baking process. In contrast, FNs above 350 seconds may indicate that the flour should be supplemented with a form of amylolytic enzyme or with malted grain flours.
Most large-scale bakeries work with an ideal FN range of 250–280 seconds. Different values of fall numbers may be specific to unique products and processing conditions inside the...