Inaccuracies in Phytic Acid Measurement: Implications for Mineral Biofortification and Bioavailability

Abstract

Biofortification of commonly eaten staple food crops with essentialmineral micronutrients is a potential sustainable solution to globalmicronutrient malnutrition. Because phytic acid (PA; 1,2,3,4,5,6-hexakismyo-inositol) reduces mineral micronutrient bioavailability, reduction of PAlevels could increase the bioavailability of biofortified iron (Fe), zinc (Zn),calcium (Ca), and magnesium (Mg). PA is viewed as an anti-nutrient, yet PA andother inositol phosphates have also demonstrated positive health benefits.Phytic acid analysis in the agricultural, food, and nutritional sciences istypically carried out by colorimetry and chromatographic techniques. Inaddition, advanced techniques such as nuclear magnetic resonance andsynchrotron X-ray absorption spectroscopy have also been used in phytic acidanalysis. The colorimetric analysis may overestimate PA levels and synchrotronX-ray absorption techniques may not detect very low levels of inositol phosphates.This short communication discusses the advantages and disadvantages of eachwidely used phytic acid analysis method, and suggests high performance anionexchange (HPAE) chromatography with conductivity detection (CD) based analysiscan achieve greater accuracy for the identification and quantification ofinositol phosphates. Accurate characterization and quantification of PA andinositol phosphates will inform PA reduction and biofortification efforts,allowing retention of the benefits of non-phytic inositol phosphates for bothplants and humans.