However, in the case of ZnD% greater time and higher temperature
soaking, the better the dialyzability. This means that the 88%
reduction of the content of phytic acid was enough to increase the
bio-accessibility of Fe but not for Zn, where a reduction of phytic acid
increased ZnD by 164.5% and 263.7% for 35 C e 24 h and 45 C e
48 h respectively, compared to brown rice.
4. Conclusion
Approximately 91% of phytic acid was removed from whole rice
by soaking the grains in acidic conditions (45 C e 48 h soaking). The
reduction was caused by the activation of endogenous phytase and
leaching of phytic acid in the soaking water. However, while protein
digestibility and mineral dialyzability were improved, soaking process
produced significant losses of minerals and proteins. Thus, acid
soaking of brown rice would not be suggested as a useful process to
reduce phytic acid from whole rice grains, if the production of a
staple food that will not be fortified is the main objective. However,
acid soaking rice could be useful to produce a low phytate starchy
ingredient to be used in rice base formulated foods.