Written by: Dr. Jacquie Jacob, University of Kentucky
Phytate is the principal storage form of phosphorus in many plant tissues, especially bran and seeds. Phytate has been shown to block the absorption of not only phosphorus but also other minerals, particularly calcium, magnesium, iron, and zinc. Phytate has also been shown to negatively affect the absorption of lipids and proteins.
Animals do not produce the enzyme phytase needed to break down phytate. As a result, diets with high levels of phytate have reduced nutrient availability. At least 75% of the total phosphorus in corn, for example, is in the form of phytate-phosphorus.
Phytate is found in many grains and legumes. The level of phytate will depend on the feedstuff and the conditions under which it was grown. Cooler temperatures during the growing season produce lentils with a reduced phytate content.
Phytase is now available as an additive to animal feeds to help with the breakdown of phytate. Crop breeders are also looking to produce low-phytate grains and legumes.