Minerals and phytates

Cereals are good sources of minerals needed for normal growth, development, and function. However, cereals are also rich in phytate (1.09–21.6 mg/g dry basis) which is a prominent antinutritional factor. Phytates reduce mineral bioavailability by forming insoluble phytate-mineral complexes that are unavailable for absorption by monogastric animals and humans. The influence of phytate on mineral bioavailability depends on its concentration, pH, and phytate:mineral molar ratio, temperature, presence of other compounds, and mineral ionic strength. Cereal phytases have the potential to hydrolyze phytate, releasing the bound minerals. Notably, the distribution, content, and interaction of phytates, minerals, and phytases vary considerably in different cereal species. Depending on the type of cereal and mineral and phytate localization, different processing techniques (soaking, fermentation, germination, thermal processing, and milling) can increase or decrease the mineral cereal contents. Conventional, modern breeding and genetic engineering can increase mineral bioavailability and/or decrease phytate content in cereal grains.