Soft wheat bran particles on a black background. Wheat bran (miller's bran), is the hard outer layer of the wheat grain consisting of the combined aleurone and pericarp. Bran is a byproduct of milling in the production of refined grains. Bran is present in any cereal grain, including rice, corn, wheat, oats, barley, rye and millet. Bran is rich in dietary fiber and essential fatty acids and contains large amounts of starch, protein, vitamins, minerals and also phytic acid. Image width: 40 mm. Magnification: 2.50x if the image is printed 10 cm wide.