Wheat flour, arabinoxylan from

Certain cereal grains, especiaUy wheat and rye, contain hemicelluloselike arabinoxylans [9040-27-1], commonly caUed pentosans. Wheat flour pentosans are divided into two types water-soluble and water-insoluble arabinoxylans, which respectively constitute - 1.1 1.6% and 0.4—0.7% of the total flour. These polysaccharides have functional roles in dough development and baking performance. The water-soluble wheat-flour arabinoxylans consist of a (1 — 4)-linked chain of P-D-xylopyranosyl units substituted at 0-2 and/or 0-3 with single-unit a-L-arabinofuranosyl units. Preparations from each source consist of a family of molecules of various molecular weights and xyl ara ratios. 

It has been established by low-temperature, n.m.r. spectroscopy1553 that wheat-flour arabinoxylan is highly hydrated. It was concluded155 1 that the well known solubility of flour arabinoxylans in water is not due to hydration, as arabinoxylans from which most of the arabinosyl groups have been removed are also highly hydrated, and that the solubility of arabinoxylans is due to arabinosyl groups that prevent associa-... 

Goldschmid and Perlin,259 using an enzyme preparation that contained a D-xylanase, isolated from Streptomyces QMB 814, to degrade wheat-flour arabinoxylan, isolated a tetrasaccharide (AX3) which was shown by chemical methods to be 0-a-L-Ara/-(l —> 3)-0-[/3-l>Xylp-(l - 4)]-/3-D-Xylp-(l -> 4)-D-Xylp (4). 

Goldsehmid and Perlin have isolated, by enzymic hydrolysis of an arabinoxylan from wheat flour, a tetrasaccharide which was shown to be 0-a-L-arabinofuranosyl-(l—>3)-0-[i3-D-xylopyranosyl-(l— )]-0- 8-D-xylopy-ranosyl-(1 4)-D-xylose. The L-arabinofuranose side-chains in this polysaccharide are thus present in the a-L configuration, in agreement with the above evidence. 

C. D. Nandini and P. V. Salimath, Structural features of arabinoxylans from sonalika variety of wheat Comparison between whole wheat flour and wheat bran, J. Set Food Agr., 83 (2003) 1297-1302. 

Dervilly-Pinel G., Tran V., Saulnier L., Investigation of the distribution of arahinose residues on the xylan backbone of water-soluble arabinoxylans from wheat flour, Carbohyd Polym., 55(3), 2004,171-177. 

Schooneveld-Bergmans, M. E. F., Dignum, M. J. W., Grabber, J. H., Beldman, G. Voragen, A. G. J. (1999). Studies on the oxidative cross-linking of feruloylated arabinoxylans from wheat flour and wheat bran. Carbohydrate Polymers, 38, 309-317. 

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