Manufactured from wheat kernels, flour is the key ingredient found in about 75 percent of all grain products.
Anatomy of Wheat Kernels
Except for whole-wheat flour, which contains all three parts of the wheat kernel, most flours are made from the endosperm after removal of the bran and germ. This decreases the nutritive value of the flour, as a large proportion of the thiamin, riboflavin, niacin, vitamin B-6, folic acid and iron present in whole-wheat kernels is absent in the finely ground endosperm flour. To compensate for the loss of the nutrients incurred during the milling process, flour is enriched with nutrients.
Enriched Versus Fortified
The process of enriching flour restores its nutritive value by replacing nutrients lost during milling in amounts similar to those lost. Almost 95 percent of the white flour in the United States is enriched with iron and four of the B vitamins: thiamin, niacin, riboflavin and folic acid. By contrast, fortified flour may contain folic acid in amounts that exceed those present in whole-wheat flour. Calcium, a nutrient that is not naturally present in wheat kernels or whole-wheat flour, is another nutrient that may be present in fortified flour.
Benefit of Enriching and Fortifying Flours
Flour enriched with iron, thiamin, riboflavin, and niacin have been part of the American diet since 1941 and have helped to eradicate beriberi and pellagra from the United States. Although folic acid fortification started only in 1998, its presence in flour is responsible for the decline in the incidence of neural tube defects in babies by 23 percent in the U.S. and by 54 percent in Nova Scotia, Canada.