Corn bran composition

Seven diets were constructed from purified natural ingredients obtained from either C3 (beet sugar, rice starch, cottonseed oil, wood cellulose, Australian Cohuna brand casein, soy protein or wheat gluten for protein) or C4 foodwebs (cane sugar, corn starch, com oil, processed corn bran for fiber, Kenya casein for protein) supplemented with appropriate amounts of vitamins and minerals (Ambrose and Norr 1993 Table 3a). The amino acid compositions of wheat gluten and soy protein differ significantly from that of casein (Ambrose and Norr 1993). 

Moreau, R.A., Singh, V., Eckhoff, S.R., Powell, M.J., Hicks, K.B. and Norton, R.A. (1999a) A comparison of the yield and composition of oil extracted from corn fiber and corn bran. Cereal... 

Phytic acid (Figure 4.3) is the hexaphosphoric ester of me o-inositol. The affinity of ferric iron for phosphoric anions, already described in connection with the ferric casse mechanism, is responsible for calcium phytate s effectiveness in eliminating iron from red wines. Under these conditions, phytic acid produces a mixed calcium-iron salt, known as Calciphos, with the following composition Ca, 20%, P, 14% and Fe +, 2%. This mixed salt is not very soluble in water and easily precipitates, thus eliminating the excess ferric iron. Phytic acid is very widespread in plants. It acts as a phosphorus reserve, located in the seed coat, i.e. in wheat, rice and corn bran. Wheat bran may be used directly to eliminate iron from wine. 

The composition of dietary fibers fed In this study as determined by TFA hydrolysis are shown In Table II. The Alphacel contained 11% hydrolyzable sugars, the xylan 77% and the corn bran 60%. The small amount of xylose recovered from the Alphacel Is most likely from hemlcellulose present In the original wood... 

Xylan and Corn Bran. The xylan and com bran fibers were mainly hemlcellulose and contained more complex mixtures of hydrolyzable monosaccharides than the other fiber sources. It was of some Interest to consider the results from the hydrolysis of fecal samples from these diets In an alternate manner. The data were replotted to show monosaccharides recovered as percent of the amount fed for each subject. (Figures 6 and 7). For comparison the composition of the original fiber Is shown on the extreme left as percent dry weight of the fiber. 

Figure 7. Recovery of monosaccharides from corn bran diets from each subject as percent of amount fed. Composition of fiber fed is shown at left.

Comparison of these two sources of hemlcellulose In the diets and their recoveries In the feces Indicated that their behavior In the gastrointestinal tract may depend both on their composition and particle size. The xylan was a finely divided preparation while the corn bran was composed of much larger particles. Very little of the xylan was recovered in the feces compared to that recovered from the corn bran. 

Table I Sugar content and composition of the hydrolysates obtained after hydrothermal treatment (160 C 60 min 8-10 g/g) of wheat bran, brewery s spent grain, corn cobs and Eucalyptus wood (5,9).

---