Unifine mill

A Unifine mill is a single one-pass impact milling system which produces ultrafine-milled whole-grain wheat flour that requires no grain pre-treatment and no screening of the flour. Like the grist or stone mills that had dominated the flour industry for centuries, the bran, germ, and endosperm elements of grain are processed into a nutritious whole wheat flour in one step. Consumers had accepted whole wheat products produced by grist or stone mills. The flour produced by these mills was quite coarse as they included the bran and the germ elements of the grain.

As the nutritional value of vitamins, micronutrients, antioxidants, phytonutrients, amino acids, and fiber, were completely or relatively unknown in the late 19th century, removing the bran and the germ with the roller mill, invented at that time, was an attractive idea. With the elimination of the bran and the germ, the resulting “white” flour composed entirely of the endosperm produced an appealing product that research has since proven to be nutritionally deficient: The endosperm contains less than half of the total minerals and B-vitamins of the wheat kernel. Perhaps as significantly is the lost total food value since the bran and germ represent 17% of the whole grain, and the process of eliminating the bran and shorts in the roller mill typically yields only 70 to 75% of grain weight as flour product, thus significantly reducing the human food supply as well.

...
Wikipedia