Cereal Chem 58:120 - 124.  |  VIEW ARTICLE
Effect of Milling on Trace Element and Protein Content of Oats and Barley.

C. M. Weaver, P. H. Chen, and S. L. Rynearson. Copyright 1981 by the American Association of Cereal Chemists, Inc. 

Barley and oats were analyzed for trace element (iron, zinc, manganese, copper, chromium, and nickel) and protein content at various stages of milling from the whole grain to flakes and flours. Trace element and protein analysis was also performed on laboratory-dissected hull and groat fractions. All nutrients studied except for chromium were significantly reduced in the milling of barley into flour, primarily as a result of decortication operations. The by-product feeds from the decortication operations, which contained the barley hulls and much of the bran, aleurone, and germ, contained higher concentrations of nutrients than did other fractions. For oats, dehulling in the preparation of groats resulted in higher levels of the nutrients studied, reflecting the lower concentration of nutrients in the hull as compared to that in the groat, except for chromium, which was greater in the hull and not reduced by dehulling. Further refining of oats into flakes and flour did not have a uniform effect on the various trace elements and protein.