Damaged Starch in Flour: What It Is, and How It Affects the Dough

Damaged starch plays a significant role in the context of amylase, fermentation, and dough behavior. As previously mentioned, alpha-amylase enzymes primarily act on damaged starch in flour because it is “easier” for the enzyme to work on; Therefore, the higher the amount of damaged starch in the flour, the more effectively the alpha-amylase enzymes can function.

If a flour contains excessive levels of damaged starch, it can yield similar outcomes to flour with a high amount of alpha-amylase, as explained in the previous section (sticky dough & crumb). On the other hand, if the flour has too little damaged starch, the yeast will not have enough food (because of limited starch break down into sugars), leading to inadequate fermentation of the dough.

In addition to its role in enzyme activity, damaged starch also has the ability to absorb much more water compared to intact starch granules.

Because the endosperm of hard wheat is tougher and more “brittle” than that of soft wheat, the milling process of hard wheat often results in a higher percentage of damaged starch compared to soft wheat. A standard damaged starch content in flour is 5-8%.