When making yeast bread, sometimes the dough just needs a little boost. One method to do that is adding a dough conditioner or dough improver.
These ingredients look like flour, but are not. They help improve gluten development to give higher volume and finer texture. Commercial bakeries use them because of the automated equipment which can be hard on bread dough. They are also added to frozen dough to withstand the damage ice crystals impart on gluten structure. Using dough conditioners can shorten mixing time and speed up fermentation.
Examples of dough conditioners include vital wheat gluten, amylase enzymes, ascorbic acid, and emulsifiers.
Source: How Baking Works, by Paula Figong