A modified method for the indirect quantitative analysis of phytate in foodstuffs.

A simple, precise, and reproducible method to quantitatively assess total phytate content in foodstuffs has been developed. After HCl extraction, samples were run through an anion-exchange column and total phytate content of the eluates was spectrophotometrically measured with the modified Wade reagent. The main changes introduced in our procedure refer to pH adjustment in the extraction, dilution, and quantitation steps (pH 0.60, 6.00, and 3.00, respectively). Furthermore, the minimal extraction time for legumes (2 h) was determined. In addition, the effect of protein content on phytate determination was tested. Phytate content directly measured in crude extracts omitting anion-exchange chromatographic purification was significantly lower (P < 0.01) than values obtained using column separation, thus demonstrating that reliable phytate assessment in foodstuffs demands the utilization of anion-exchange chromatography.