These are made up of the starch, dextrins, pentosans (polysaccharide sugars that bind substantially in water), cellulose, and sugars contained in the milled flour. Almost all of the pentosans and cellulose are removed during the milling process. The starch granules that have been altered during milling are the most valuable source in the development of yeast-based bread doughs, as they help, when impacted by the amylase enzymes, to produce the sugars necessary to feed the yeast during the fermentation process.