Corn arabinoxylan

K.S. Mikkonen, M.P. Yadav, P. Cooke, S. Willfor, K.B. Hicks, and M. Tenkanen, Films from spruce galactoglucomannan blended with poly(vinyl alcohol), corn arabinoxylan, and konjac glucomannan, BioResources, 3 (1), 178-191,2008. 

Ethanol-precipitated GGM was more effective than the other studied mannans, and was almost as effective as corn arabinoxylan, which is considered to be a good stabilizer. The study gave the first indication of spruce GGM as a potential stabilizer of food emulsions and was much in line with the previous stabilizing studies of pitch emulsions [51]. 

In contrast to AGX, the GAX consists of an arabinoxylan backbone, which contains about ten times fewer uronic acid side chains than a-L-Ara/ ones, and has some Xylp residues doubly substituted with these sugars. GAX are located in the non-endospermic tissues of cereal grains such as in wheat, corn, and rice bran. The degree and pattern of substitution of GAX appears to vary with the source from which they are extracted. These differences are reflected in the ratio of Ara to Xyl, the content of MeGlcA, and the presence... 

In a most recent paper [418] the preparation of corn fiber arabinoxylan esters by reaction of the polymer with C2-C4 anhydrides using methanesul-fonic acid as a catalyst is described. The water-insoluble derivatives with high molecular weight showed glass-transition temperatures from 61 to 138 °C, depending on the DS and substituent type. The products were thermally stable up to 200 °C. Above this temperature their stability rapidly decreased. 

XOS are manufactured by enzymatic hydrolysis of xylan from corn cobs, oat spelt xylan or wheat arabinoxylan [257]. Xylan, a principle t)q)e of hemicellulose exists as a linear polymer of -D-xylopyranosyl units linked by 1 4 glycosidic bonds. Depending on the origin, different substituents such as arabinfuranosyl, 4-0-methylglucuronosyl and acetyl groups are present. Typical raw materials for XOS production include hardwoods, com cobs, straws. 

Doner, L. W., Johnston, D. B., and Singh, V., Analysis and properties of arabinoxylans from discrete corn wet-miUing fiber fractions, J. Agric. Food Chem., 49, 1266, 2001. 

Schizophyllum commune Corn fiber containing 30-50% arabinoxylan, 15-20% cellulose, 20% adherent starch, and 11-12% protein (composed of seed pericarp and adherent starch) Schizophyllan and arabinoxylan 90... 

Figure L The change in weight-average molecular weight and the carbohydrate composition over an extended time period during acetylation of corn fiber arabinoxylan using 0.65 wt% MSA at 25 °C. Reproduced with permission from reference 19. Copyright 2002 Elsevier Science Ltd.

Figure 4. GPC curves for unmodified corn fiber arabinoxylan (AX) and for the acetate (AXA), propionate (AXP), and butyrate (AXE) esters of the arabinoxylan. Reproduced with permission from reference 19. Copyright 2002...

Ferulic acid is ubiquitously present in plants, mainly as part of the cell walls esterified to polysaccharides such as arabinoxylans. It is also an intermediate in the secondary metabolism of phenylalanine and tyrosine. It can be conveniently isolated from corn hulls, rice bran, and sugar beet. Biocatalytic processes using cinnamoyl esterases and glycosyl hydrolases have been developed for this purpose [32]. Another potentially interesting source is lignin, since ferulic acid is one of the prominent byproducts of its degradation. 

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