Submitted to: Cereal Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/2/2000
Publication Date: 3/2/2000
Interpretive Summary: Corn fiber, a product of corn wet milling, contains a valuable gum that can be recovered using a novel alkali hydrogen peroxide extraction process. Corn fiber gum has several useful properties for potential use in various industrial and food applications. Industrial corn fiber is mixture of coarse fiber (pericarp) and fine fiber (cellular fiber). In this study we separated the pericarp and the cellular fiber and recovered corn fiber gum from individual fiber fractions (i.e. coarse and fine) for three yellow dent corn hybrids. Comparison showed that there are no significant differences in the corn fiber gum yields but significant differences in the sugar composition of the corn fiber gums from coarse and fine fiber fractions. Differences in sugar profiles suggest that there may be differences in the properties of the gums which can be exploited for unique industrial and food applications.
Technical Abstract: Most corn fiber is prepared by the corn wet-milling industry, where it is commonly known as white fiber. White fiber is a mixture of corn coarse fiber (also known as pericarp, or bran) and the corn fine fiber (or the inner cellular fiber). Most of the research on corn fiber gum, including yields and sugar composition profiles of the polysaccharide has been done using white fiber as the starting material. There is lack of information on the corn fiber gum yields and their sugar profiles for individual (i.e. coarse and fine) fiber fractions. In this study comparison was done for three commercial corn hybrids between the coarse and fine fiber fractions (obtained under controlled laboratory conditions) for corn fiber gum yields and the sugar composition profiles for the polysaccharides. No significant differences were observed in the corn fiber gum yields from coarse and fine fiber fractions. However, there were significant differences in the sugar composition of the corn fiber gums from coarse and fine fiber. The result suggest that in the fine fiber, the beta- D-xylan backbone is much more heavily branched with arabinose units, with arabinose/xylose ratios averaging 0.836. This ratio in coarse fiber is just 0.627, on the average. The average glucuronic acid was 1.5% higher in the fine fiber fraction compared to that in the coarse fiber fraction. No significant differences was observed in the average galactose content, the remaining sugar in the corn fiber gum polysaccharide. These differences in sugar profiles should result in differences in properties between corn fiber gums from fine and coarse fiber.