20 BULLETIN 1152, IT. S. DEPARTMENT OF AGRICULTURE. • 
The peanut also contains starchy substances and in the broken cells 
composing the press cake these starchy compounds are at once avail- 
able as food for prompt mold growth. When the usual Japanese 
shoyu-koji process is followed, the soy-bean tissue is practically 
unbroken, except that the seed coats are usually split at some point. 
The mold penetrates the seed coats, the germ, and the cell structure 
of the cotyledons to a limited extent. The food substances, how- 
ever, are not as immediately obtainable in the uncrushed soy bean 
as in press cake. 
The control of bacterial activity is much more difficult in a koji 
made of press cake than in one made of whole seeds. The food 
materials made available by crushing the plant cells are directly 
accessible to bacteria unavoidably introduced in cooling, distributing, 
and seeding the koji. The life cycle of the bacteria is shorter, and 
therefore their work is more speedily accomplished than that of the 
molds. When mold fermentation is desired, bacterial growth must 
be inhibited and obstructed at every possible point. Water content 
of the koji mixture, temperature control, and degree of humidity 
permitted are the important factors. The degree to which bacterial 
activity is controlled in a koji where mold fermentation is desired 
is an indication of the quality of that koji. 
The peanut press cake koji was made into a moromi having an 
initial salt content of 11 to 12 per cent sodium chlorid. 8 Evaporation 
through January to September, 1920, increased the salt content 
gradually. The extent of evaporation in the mash was such that the 
salt content of the sauce was about 19 per cent sodium chlorid. 9 The 
sauce was secured from the mash by pressing. 
The quality of the peanut sauce was very satisfactory. The taste 
of the peanut was retained to such an extent that those accustomed 
to judging peanut products by tasting were not deceived, even when 
uninformed as to the ingredients of the sauce. The peanut sauce, 
although not having the flavor desired by the Japanese in shoyu, 
was very acceptable, combining the natural taste of the peanut with 
a mild meaty flavor. 
RELATION OF ENZYMIC ACTIVITY TO SOY PROCESSES. 
Certain changes occur in the mixture of mold, beans, and wheat 
after it has stood in the brine as moromi to ripen for a period of time. 
Doubtless these are not due to any activity of the salt, which is a re- 
strictive agent. The essential factors are the diastatic and proteoly- 
tic enzymes produced by the mold. Having become satisfied of the 
certainty of these two points, inquiry may be made as to what part 
the enzymes of the bacteria play. Bacteria are undoubtedly present 
and to a certain degree they are active. Increasingly great numbers 
of bacteria in the koji cause an undesirable flavor in the final sauce. 
The same may be said of uncontrolled bacterial activity in the mash. 
In other terms, low salt content, below 16 per cent, and higher tem- 
peratures, above 22° to 24° C, influence the flavor of the mature soy 
sauce to such a degree that the flavor deemed desirable in a good 
sauce by the oriental people is not usually secured. 
8 Analysis by J. F. Brewster, formerly of Bureau of Chemistry, United States Depart- 
ment of Agriculture. 
9 Analysis by C. E. Goodrich, Bureau of Chemistry, United States Department of Agri- 
culture. 
