Rye flour does contain a relatively large number of pentosans that contribute to dough viscosity.
Because of these characteristics, rye bread made for ONLY rye flour will be denser and chewer in texture than wheat bread. Rye flour may be graded or bought as to different types, based on the degree of bran removal, or purification, during milling. There is a whole-grain rye flour called pumpernickel flour, dark rye, medium rye or white rye. The greater the bran removal in milling the lighter in color, lower in protein and dietary fiber and the blander in flavor. Preparation And Chemical Characteristics Of The Cohesive Proteins Of Wheat, Barley, Rye, And Oats.