Refined grains

The modification process generally involves the mechanical removal of bran and germ, either through grinding or selective sifting.

[2] Refined grains are milled which gives a finer texture and improved shelf life.

[4] After refinement of grains became prevalent in the early 20th-century, nutritional deficiencies (iron, thiamin, riboflavin and niacin) became more common in the United States.

[5][6] To correct this, the Congress passed the U.S. Enrichment Act of 1942 which requires that iron, niacin, thiamin and riboflavin have to be added to all refined grain products before they are sold.

[5] Refining grain includes mixing, bleaching, and brominating; additionally, folate, thiamin, riboflavin, niacin, and iron are added back in to nutritionally enrich the product.