A MODIFIED METHOD FOR THE INDIRECT QUANTITATIVE-ANALYSIS OF PHYTATE IN FOODSTUFFS

A simple, precise, and reproducible method to quantitatively assess to tal phytate content in foodstuffs has been developed. After HCl extrac tion, samples were run through an anion-exchange column and total phyt ate content of the eluates was spectrophotometrically measured with th e modified Wade reagent. The main changes introduced in our procedure refer to pH adjustment in the extraction, dilution, and quantitation s teps (pH 0.60, 6.00, and 3.00, respectively). Furthermore, the minimal extraction time for legumes (2 h) was determined. In addition, the ef fect of protein content on phytate determination was tested. Phytate c ontent directly measured in crude extracts omitting anion-exchange chr omatographic purification was significantly lower (P < 0.01) than valu es obtained using column separation, thus demonstrating that reliable phytate assessment in foodstuffs demands the utilization of anion-exch ange chromatography. (C) 1995 Academic Press, Inc.