Made from coarsely ground rye, pumpernickel is one of the most antioxidant-rich breads among those tested. Undoubtedly, this has much to do with the fact that it is less processed. Made from a blend of rye flour and whole rye berries, it is the latter which are especially a good source of antioxidant content. Why? Because in almost all grains, the nutrients are concentrated in their shells or skin. In heavily processed breads (like white) the flour is highly processed with little to no grain skin, and hence, little to no nutritional value too.
ORAC Source
USDA Database for the Oxygen Radical Absorbance Capacity (ORAC) of Selected Foods, Release 2 - Prepared by Nutrient Data Laboratory, Beltsville Human Nutrition Research Center (BHNRC), Agricultural Research Service (ARS), U.S. Department of Agriculture (USDA) - May 2010