Cereal Chem 59:373 - 378.  |  VIEW ARTICLE
Semiautomated Determination of Phytate in Sorghum and Sorghum Products.

C. Doherty, J. M. Faubion, and L. W. Rooney. Copyright 1982 by the American Association of Cereal Chemists, Inc. 

Thirty sorghum varieties were analyzed for phytate phosphorus (phytate-P) using a semiautomated method. Phytic acid was isolated by extraction with dilute (HCl-Na2SO4 and precipitated as Fe(III)-phytate through addition of FeCl3. Following precipitation, Fe(III)-phytate was digested utilizing the micro-Kjeldahl procedure to release phytate-P. Phytate-P was determined colorimetrically using a modified Technicon method. Whole sorghums analyzed contained phytate-P levels of 0.17-0.38% (dry wt), accounting for 80- 87% of the total phosphorus in the kernel. These levels were comparable to those in other cereals. Highest levels of phytate-P were found in the bran fraction, with lesser amounts in the whole grain and dehulled grain, respectively. The method was employed to quantify phytate-P in wheat, corn, and oilseeds (cottonseed and soybean flours). Processing effectively concentrated phytate-P levels in both sorghum and corn tortillas, whereas total phosphorus levels (total-P) remained unchanged. To, a thick African porridge prepared under acid conditions, had slightly less phytate-P than its parent flour. Overall error for the method was less than 5%.