Damaged starch

Damaged starch arises during milling: the starch granules can experience mechanical damage when wheat is ground, and the level of damage is related to wheat hardness and milling conditions.

The damaged granules behave differently. They absorb more water than native granules, which raises the water absorption capacity of the flour, and they are more readily hydrolyzed by amylases. A research paper tested combinations of alpha-amylase and amyloglucosidase to offset the dough and bread problems that high damaged starch causes.

A Canadian baking textbook also uses the term: it says damp weather at harvest can cause sprouting, producing what it calls damaged starch, and that a flour can contain too much damaged starch to count as high quality even when its protein content is high. Bakers watch it because it changes how much water a dough takes up and how fast it ferments.