The role of phytic acid in legumes: antinutrient or beneficial function?

This review describes the present state of knowledge about phytic acid (phy tate), which is often present in legume seeds. The antinutritional effects of phytic acid primarily relate to the strong chelating associated with its six reactive phosphate groups. Its ability to complex with proteins and pa rticularly with minerals has been a subject of investigation from chemical and nutritional viewpoints. The hydrolysis of phytate into inositol and pho sphates or phosphoric acid occurs as a result of phytase or nonenzymatic cl eavage. Enzymes capable of hydrolysing phytates are widely distributed in m icro-organisms, plants and animals. Phytases act in a stepwise manner to ca talyse the hydrolysis of phytic acid. To reduce or eliminate the chelating ability of phytate, dephosphorylation of hexa- and penta-phosphate forms is essential since a high degree of phosphorylation is necessary to bind mine rals. There are several methods of decreasing the inhibitory effect of phyt ic acid on mineral absorption (cooking, germination, fermentation, soaking, autolysis). Nevertheless, inositol hexa-phosphate is receiving increased a ttention owing to its role in cancer prevention and/or therapy and its hypo cholesterolaemic effect.