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ARS Home » Southeast Area » Raleigh, North Carolina » Soybean and Nitrogen Fixation Research » Research » Publications at this Location » Publication #210329
Title: A modified colorimetric method for phytic acid analysis in soybean

Author
item GAI, Y - VPI & STATE UNIV
item SHANG, C - VPI & STATE UNIV
item SAGHAI MAROOF, M. - VPI & STATE UNIV
item BIYASHEV, R. - VPI & STATE UNIV
item GRABAU, E. - VPI & STATE UNIV
item Kwanyuen, Prachuab
item Burton, Joseph
item BUSS, G. - VPI & STATE UNIV

Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/1/2007
Publication Date: 9/1/2007
Citation: Gai, Y., Shang, C., Saghai Maroof, M.A., Biyashev, R.M., Grabau, E.A., Kwanyuen, P., Burton, J.W., Buss, G.R. 2007. A modified colorimetric method for phytic acid analysis in soybean. Crop Science 47:1797-1803.

Interpretive Summary: A modified colorimetric Wade reagent method for assay of phytic acid in soybean has been developed. Comparison of the newly developed method with anion exchange column chromatography (AEC), high performance liquid chromatography (HPLC), and 31P nuclear magnetic resonance (NMR) using 42 soybean lines with wide range of phytic acid content has indicated that this modified colorimetric method was precise and reproducible. This method is simpler and less expensive for assaying a large number of samples, and allows its effective application in breeding and genetic studies of phytic acid metabolism in soybean.

Technical Abstract: A quantitative, reproducible, and efficient phytic acid assay procedure is needed to screen breeding populations and support genetic studies in soybeans. The objective of this study was to modify the colorimetric Wade reagent method and compare the accuracy and applicability of this new method in determining seed phytic acid content in soybean with three well-established phytic acid assay methods, including anion exchange column (AEC), high performance liquid chromatography (HPLC), and 31P nuclear magnetic resonance (NMR). The CV for repeated measurements of a low phytic acid soybean mutant, CX1834-1-6, ranged from 1.8 to 4.2% (n = 5), indicating that this modified colorimetric method was precise and reproducible. Phytic acid content of 42 soybean genotypes with PA ranging from 6 to 22 mg g-1 as determined by this method was 93.7 to 96.6% correlated to the measurements by AEC, HPLC, and NMR. According to analysis of covariance, using inorganic P content as a predictor, phytic acid-P content in a given sample analyzed by the four assay methods can be estimated with four linear regression models at ' = 0.01 level. In comparison, this modified colorimetric method is simpler and less expensive for assaying a large number of samples than HPLC, AEC, and 31P-NMR. This allows its effective application in breeding and genetic studies of low phytic acid soybean.