Hydrolysis of phytic acid with purified exogenous phytase was attempted and the evolution of the m-inositol polyphosphate pattern followed by HPLC. After 24h of hydrolysis, reduction of total phytates by this process amounted to 37%, the hexaphosphate (IP6) continued to be the predominant fraction (81%), whereas the IP4 and IP3 components remained negligible (0.3 and 0.5%, respectively). We conclude that the minor variations observed in the distribution profile are indicative of a serial-type enzyme mechanism, while the inefficient action of exogenous phytase on the stabilized rice bran is confirmed.
rice bran; phytic acid; functional food; phytase; mechanism
