The relation of the temperature and time of incubation of “koji” to the powers of its enzymes as studied with flasks in a laboratory.

Abstract

1) “Koji” has been incubated at three different temperatures i. e. 33, 38 and 42°C. and duringthree different times i. e. 43, 51, and 59 hours. Then the conditions of its incubation are investigated by “two factorial design of experiments” or 1 “randomixedblocks” of statistical method.
2) “Koji” incubated at the temperature of 38°C. is stronger than the others in the power of dextrinization.
Prolongation of the incubation time seems to increase the same power of “koji” incubated at all the three.
3) As to the saccharifying power, the temperature of incubation has not so large influence at least in the range of these temperatures.
Also the prolongation of the incubation time has only a small effect.
4) When “koji” is incubated at the temperature. above 33°C. the power of alkaline protease decrease inversely with the increase of the incubation temperature ; at higher temperature the power of this enzyme is extremely small.
While the power increases with the prolongation of time when incubated at 38°C., the same phenomenon has not always been seen at the other temperatures.
5) As to the acid protease it can be said that “koji” incubated at 33°C. shows the highest activity as in the case of alkaline protease.
On the other hand the prolongation of the icubation time is not so large a factor to, have.: an influence of the power of both proteases.