Overestimation of phytic acid in foods by the AOAC anion-exchange method
1992
Lehrfeld, J. | Morris, E.R.
The currently used AOAC method may overestimate the phytic acid (inositol hexaphosphate) content of processed foods. These foods generally contain the lower phosphates (inositol penta-, tetra-, and triphosphate) in addition to phytic acid. These lower phosphates are included in the calculation of phytic acid determined by the AOAC anion-exchange method. The HPLC method quantitates phytic acid and the other inositol phosphates as separate entities. Research has indicated that phytic acid, and to a lesser degree other inositol phosphates, may reduce mineral bioavailability of foods. Consequently, a method that measures the individual inositol phosphates will more accurately predict the potential negative effect on mineral bioavailability. Phytic acid content of a human diet, an oat breakfast cereal, a wheat bran sample, and a sample of sodium phytate was determined according to the AOAC method and an HPLC method. The values obtained were in good agreement when the sample contained only phytic acid. However, the values diverged when samples contained appreciable amounts of inositol penta-, tetra-, and triphosphate.
显示更多 [+] 显示较少 [-]