RESEARCHES ON THE MANUFACTURE, 
Q9 
Oäj 
the latter 6-12% by weight Ferments appear, however, to be 
rather sensible to the presence of neutral soluble salts, and to 
be weakened by them. An addition of sodium chloride to a 
mixture of malt extract and gelatinized starch diminished 
according to O Nasse 12 the amount of sugar so much that, 
while under equal conditions without any addition of sodium 
chloride 100 parts of sugar were formed from the starch, only 
£3 parts were obtained in the presence of 4% of this salt. In 
order to ascertain whether and how far the koji ferment is 
weakened by an addition of common salt to its solutions we 
carried out the following experiments: 
I. Solutions containing 2% of air-dry starch prepared 
according to the proposal of Lintner jun., 200 c.c. each, were 
mixed with 45 c.c. of an extract made with 500 c.c. of water 
from 25 grms of barley koji, and various quantities of sodium 
chloride were added. These mixtures were kept in water of 
40°C. for 2 hours, and then the quantities of reducing sugars, 
calcutated as dextrose were determined by titration with 
Fehling’s solutions. The results, after deduction of the 
contents of the original koji extract, were, as follows : 
Sodium chloride 
in % of the mix¬ 
ture. 
Reducing sugars 
as dextrose. 
Relative 
proportions. 
0 . 
.0.271%. 
.100 
2.0. 
.0.091 .. 
. 33.6 
9.3. 
. 20.3 
17.6. 
.traces. 
The koji applied in this trial was a little old and not very 
effective. 
II. Another series of experiments was made with rice koji, 
the same proportion of starch solution and koji extract as 
above being used. The quantities of reducing sugars pro¬ 
duced from the starch and calculated as dextrose were found 
to be the following : 
O 
12 M. Maercker Handbuch d. Spiritusfabrikation. 1880) S53. 
