Action of rice bran phytase on hydrolysis of phytin

The hydrolytic activity of rice bran phytase in relation to phytin and other inositol phosphates has been studied. The maximum activity is exhibited at pH 5.2 and 50°C. Being present in a state of binding with hydrated phytin complexes, phytase hydrolyses endogenous phytin intensively. The affinity of the enzyme present in the form of the complex with exogenous sodium phytate is extremely low. The results of the investigation have provided the possibility of revealing the reasons for the quantitative change in the amount of phytin in rice bran as a function of the technological parameters of the heat treatment of the raw material and the extraction of inositol phosphates.