Sources of phytic acid in food are cereals, legumes, oilseeds and nuts which are important for human nutrition.
- cereals are rich in phytate and cereal food products show higher phytic acid content
- phytic acid concentration reported in wheat germs and wheat bran are 1.1–3.9 % and 2.0–5.3 %
- in rice bran, the phytic acid content is present upto 8.7 %
- phytic acid content varies from approx. 1.0–5.4 % in oilseeds such as soybeans, sesame seeds, sunflower kernels, linseeds and rape seeds
- in nuts such as walnuts, almond, cashew nuts etc. phytic acid content ranged from approx.0.1–9.4%
Phytic acid (known as inositol hexakisphosphate, or phytate when in salt form)
- principal storage form of phosphorus in many plant tissues - particularly bran and seeds
- phytate is not digestible to humans or nonruminant animals
- therefore it is not a source of either inositol or phosphate if eaten directly
- phytate chelates and thus makes unabsorbable certain minerals such as zinc and iron
- phytic acid is negatively charged and, thus, strongly chelates cations such as calcium (Ca), magnesium (Mg), potassium (K), iron (Fe) and zinc (Zn) and usually exists as mixed salts referred to as phytate or phytin
- these very insoluble salts prevent the absorption of important nutrients in the human intestine that may then lead to micronutrient deficiencies
Reference:
- Gupta RJ et al.Reduction of phytic acid and enhancement of bioavailable micronutrients in food grains. J Food Sci Technol (February 2015) 52(2):676–684.