Submitted to: Cereal Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/2/2012
Publication Date: 5/23/2012
Publication URL: http://naldc.nal.usda.gov.d2.nal.usda.gov/download/54125/PDF
Citation: Kiszonas, A.M., Courtin, C.M., Morris, C.F. 2012. Quantification of Wheat Grain Arabinoxylans Using a Phloroglucinol Colorimetric Assay. Cereal Chemistry. 89:143-150. Interpretive Summary: The objective of this work was to evaluate a common method of arabinoxylan quantification in wheat using a phloroglucinol colorimetric asssay. Upon evaluation of the method, improvements were made to increase the consistency of the method across multiple operators. Along with these improvements, a determination of the stability of the end-product over time was studied. Lastly, the results of the improved method were compared with another often-used method for arabinoxylan quantification to determine how similarly the methods quantified arabinoxylans.
Technical Abstract: Arabinoxylans (AX) play a critical role in end-use quality and nutrition of wheat (Triticum aestivum L.). An efficient, accurate method of AX quantification is desirable as AX plays an important role in processing, end use quality and human health. The objective of this work was to evaluate a standard phloroglucinol colorimetric method for quantification of wheat AX. Method parameters were varied to identify areas for improved accuracy. The reaction reagents, water bath, and hydrolysis times were varied. The phloroglucide product, which resulted from hydrolysis of xylose and reaction with phloroglucinol, was examined over time for changes in absorbance at three xylose concentrations. The optimal reaction reagents and hydrolysis times were determined based upon consistency in absorbances. The optimized method was used to test xylose monosaccharide standards and whole meal wheat samples for ‘AX’ content. The use of the optimized method can help increase uniformity between operators and among replications for the determination of AX in whole meal samples.