1987 Volume 82 Issue 9 Pages 646-650
During sake brewing with puffed brown rice, rapid progress of rice digestion was observed from the early stage of moromi mash.
Among the minerals in moromi mash of puffed brown rice, K, P and Mg ions contents were10-43 times more than those of 75% polished rice, but Zn, Ca and Mn ions contents were aboutthe same.
By the addition of K, P and Mg ions, the digestion of steamed rice (75% polishing ratio) byrice-koji accelerated, and among them Mg ion was the most effective.
The elution of a-amylase, glucoamylase and acid protease from rice-koji or steamed rice to the supernatant at rice digestion accelerated by the addition of these three ions, and among them Mg ion was also the most effective.
The mineral concentrations for maximal rice digestion rate were 500 ppm or more for K and P ions, and 300-500 ppm for Mg ion respectively.
