In mature seeds, phytate (IP6, myo-inositol) is present primarily as the hexaphosphate. Processing of food, however, leads to hydrolysis of this hexaphosphate to tri, tetra, and penta inositol phosphate. Evidence suggests that at least some of these hydrolysis products have much less affinity or less potential for reducing the bioavailability of minerals. Hence a better understanding of the role of phytate and its hydrolysis products in processed foods would be of value. In a previous review by Harland and Morris (1), the authors presented limited data on phytate-containing foods and their hydrolysis products. In this publication, additional foods with the phytate content and their hyudrolysis products will be presented. Although a number of investigators have addressed this issue, due to differences in their findings, there is a general lack of consistency in the results. This publication contains a summary of current research involving humans, animals, plants, soils, phytases and genetic engineering to reduce phytate levels in foods and feeds. A table of values for phytate in foods and the hydrolysis products is also presented, (C) 1999 Elsevier Science Inc..