Corn bran fibers

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). 

Diet Codes rwb = red wheat bran wwb = white wheat bran cb = corn bran rb = rice bran pf = psyllium fiber p = pectin c cellulose... 

Corn bran is the dried fiber fraction. The protein content is about 10%. Its only use is in beef or dairy cattle feeds. A purified form of com fiber has been offered to the food industry for use in high fiber food products.246... 

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... 

Honig, D.H. J.J. Rackis. Determination of the total pepsin-pancreatin indigestible content (dietary fiber) of soybean products, wheat bran, and corn bran. J. Agric. Food Chem. 1979, 27. 1262-1266. 

Smith-Barbaro a. (26) in our laboratory determined the capacity of various fibers to bind the colon carcinogen 1.2-di-methylhydrazlne (DMH) in vitro. The percent of DMH bound to wheat bran, corn bran, alfalfa fiber and dehydrated citrus pulp was dependent on pH of the medium as well as the type of fiber examined. Results from this study show that at colonic pH, a greater percent of DMH was bound by wheat bran than by citrus pulp. Therefore, it is possible that certain fibers bind carcinogen at colonic pH, thus making it unavailable for contact with the colonic mucosa. Other fibers such as pectin (soluble fiber) do not bind DMH at colonic pH, but may modify the metabolism of carcinogen via actlvation/deactlvatlon steps either in the liver and/or in the colonic mucosa. 

Acid hydrolysis of hitman fecal samples collected after Ingestion of different dietary fibers produced monosaccharides that were related to the fibers Ingested. Dietary fibers studied In five normal male subjects were cellulose, xylan, corn bran and pectin. Increases In monosaccharides In recovered hydrolyzed feces from fiber diets compared to those from the fiber-free diet were galactose for the pectin diet xylose and glucose for the cellulose diet xylose and mannose for the xylan diet and arablnose, xylose, galactose and glucose for the corn bran diet. Comparison of the fecal results to those for the Intact food fibers showed that fermentation of fiber components In the colon was different for each fiber. 

During the test, dietary fiber was provided with each meal. Alphacel, xylan, and pectin were fed at 0.5g/kg body weight per day. Corn bran was considered to be approximately 80% dietary fiber and was fed at 0.6g/kg body weight. Each fiber was consumed as a pudding containing other dietary constituents. The remaining dietary constituents were consumed as a milkshake style drink. 

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. 

Corn bran has a large xylose to arablnose ratio of 1.8. Recovery of these sugars In the feces was the highest of any of the fibers fed. The xylose to arablnose ratio was eilso close to that In the bran fed, ranging from 1.5-1.7. Galactose, while In quite small amounts, survived In roughly the same... 

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.

Mahalko JR, Sandstead HH, Johnson LK, et al. Effect of consuming fiber from corn bran, soy hulls, or apple powder on glucose-tolerance and plasma-lipids in type-ii diabetes. Am ] Clin Nutr. 1984 39(1) 25 —34. 

The outer coarse coat (pericarp) of grain which is separated in milling. Wheat, oat, rice, and corn bran are most common. Bran contains a large part of the valuable nutrients found in grains. It is the most popular food for the purpose of increasing bulk in the diet. Most nutritionists recommend that healthy adults get 20 to 35 g of fiber per day. 

Utilization of iron was not affected at levels of 9 to 26g bran/day from corn or wheat (19, 2J0 2 ) or bY 16 g of bran/day (25). Negative balances were observed by Morris and Ellis (21) during the first balance period with daily intakes of 36g bran but not during the second 5-day balance period. However, Simpson et al. (24) found a marked inhibition of non-heme iron absorption from a single test meal which included 6 g of wheat bran. With a diet which provided 35g/day of NDF (neutral detergent fiber from bran bread), iron balances were decreased (26) compared to the 9 or 22g/day intake levels. 

Oat cereal has more fiber than corn cereal but less fiber than bran cereal. 

Phytate has been studied extensively with regard to mineral (mostly Zn and Ca) status of animals, and it has been shown to reduce whole-body Mn retention in rats (12). Phytate, however, is not present in the neutral detergent fiber or in the ash component of feedstuffs. Therefore, phytate does not appear to be responsible for the reduction of Mn uptake in chicks fed corn, soybean meal, wheat bran or fish meal (9). That phytate negatively impacts Mn nutriture also disagrees with the research of Reinhold et aK (13), who reported that fiber, and not phytate, was the pTTmary factor determining bioavailability of divalent mineral elements in breads. 

The commodity vegetable oils can be classified in various ways. Some are byproducts so that decisions regarding their production are largely controlled by the nonoil component. Examples are corn oil and cottonseed oil. These are byproducts of cereal and fiber production, respectively. Also, rice bran oil is a byproduct of rice production. As a consequence, oil production is not the main economic factor that influences the areas cultivated by these crops. It is sometimes argued that soybean falls into this byproduct category and that the bean is grown as a source of protein with the oil as byproduct. It is true that the bean produces only 18% of oil against 79% of residual meal rich in protein, but the value of these two commodities is evenly balanced and there are times when the demand is oil-led and other times when it is meal-led. 

The cotyledon co-product is processed, dried, and sold as a dietary fiber in competition with other sources such as a-cellulose, psyllium seed, guar gum, locust bean gum, pectin, and wheat, corn, and oat brans. Manufacturer s specifications for a domestic product include 75% (mfb) dietary fiber (65% noncellulosic polysaccharides and 10% cellulosic), 12% moisture, 0.2% fat, and 4.5% (as is) ash. 

The relation between dietary fiber consumption and colon cancer has been studied in experimental animals. Wilson t al. (35) found that Sprague-Dawley rats fed a diet containing 20% corn oil or beef fat and 20% wheat bran had fewer benign colon tumors Induced by DMH given by gastric intubation than rats fed a control diet containing 20% fat and no bran. It is possible that with additional time, a number of tumors that were classl-... 

Corn and wheat bran contain considerable amounts of hemlcellulose but not at the high levels found in psyllium. Furthermore, the water-holding capacity of these two fiber sources were not as high as those for psyllium. Hence, it would appear that fecal residual fiber is perhaps not a good index of functionality of... 

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