Phytic acid and phosphorus in crop seeds and fruits: a global estimate

A very important mineral storage compound in seeds is phytate, a mixed cati on salt of phytic acid (myo-inositol hexakis phosphoric acid). This compoun d is important for several reasons: (1) It is vital for seed/grain developm ent and successful seedling growth. (2) It is often considered to be an ant inutritional substance in human diets, but it may have a positive nutrition al role as an anti-oxidant and an anti-cancer agent. (3) It represents a ve ry significant amount of phosphorus being extracted from soils and subseque ntly removed with the crop. (4) It plays a role in eutrophication of waterw ays. A key part of this review is an estimate of the annual tonnage of phos phorus and phytic acid sequestered in up to 4.1 billion metric tonnes of cr op seeds and fruits globally each year. We estimate that nearly 35 million metric tonnes of phytic acid, containing 9.9 million metric tonnes of P, is combined with about 12.5 and 3.9 million metric tonnes of K and Mg respect ively, to form each year over 51 million metric tonnes of phytate. The amou nt of P in this phytate is equal to nearly 65% of the elemental P sold worl d wide for use in mineral fertilizers. Dry cereal grains account for 69% of the total crop seed/fruit production but account for 77% of the total phyt ic acid stored each year. Low phytate mutants, that are now available for s ome key staple food crops such as maize and barley, offer potential benefit s in such areas as the sustainability of lands used to grow crops, the mine ral nutrition of humans and animals, and reduction in pollution of waterway s.