Quantification of total and water soluble arabinoxylan
As, per the method of Finnie, Bettge, and Morris (2006), 125 mg
flour was weighed in polypropylene tubes and 25 mL water was
added. After vortexing the tube, 1 mL of suspension was immediately pippetted and used to determine the total arabinoxylans.
The original suspension was then extracted at 25 C for 30 min in
shaking incubator (Narang Scientific works, India) and centrifuged
at 2,500g for 10 min, after which 1 mL supernatant was taken and
used to determine the soluble arabinoxylans. Further, the total and
soluble arabinoxylans were determined in the respective aliquots
as per the colorimetric method described by Douglas (1981). Stock
solution of D-(+)-xylose (X-1500, Sigma) was prepared by dissolving its required amount in water and further dilutions were made
in series, for preparation of standard curve. A linear equation was
generated for the standard curve, which was used for calculating
the total and soluble arabinoxylans using the respective absorbance values. The result was expressed in percent (%). Insoluble
arabinoxylans were calculated by difference (Total arabinoxylans soluble arabinoxylans). The tests were performed in
triplicates.