Phytate content in cereals and legumes and methods of determination

Abstract

Phytate is found in all seeds; mature legumes and cereal grains have the highest concentration. Phytates do not have a characteristic absorption spectrum. A brief history of phytate isolation is presented along with a description of its chemical structure. Phytates are important because they are the major phosphorus form in mature plant seeds, not absorbed from the GI tract, and hydrolyzed only slightly in human and animal intestines. Only recently has it been possible to differentiate the various degrees of phosphorylation and stereoisomers in phytates. Thus phytate analyses has been limited. The method showing the greatest sensitivity, accuracy and speed is high-performance liquid chromatography which appears to detect sensitivity at the microgram level; whether this has any biological or nutritional significance is questionable. Another alternative measure for foods or food products is the union exchange chromatographic procedure. (kbc)