However, the bioavailability of soymilk calcium, both endogenous
and fortified, is limited by phytic acid (inositol hexaphosphate)
naturally present in soybeans which strongly chelates
divalent cations (Ma´rquez and Wagner, 2010). The bulk of phytic
acid is found in the cotyledons. The cotyledons contain as much as
1.6% phytic acid, which is localized in the protein bodies and
appears to be distributed between soluble protein–phytate salts
and insoluble globoid inclusions (Anderson and Wolf, 1995). The
release of phytic acid resulting from the disintegration of
cotyledons in soymilk production renders the chelator more
active, which furhter reduces the bioavailability of calcium.