
FUNGI IN CHEESE RIPENING. 85 
produce purple tones instead of sharply marked areas of red and 
blue. The data seem to indicate that chemical decomposition 
or neutralization of acid must be the action of some product 
excreted by the fungus, probably an enzyme. 
It has thus been shown by many experiments that the Ca- 
membert Penicillium and Oidium lactis are two of many species 
capable of reducing the acidity of the media upon which they 
grow. Many other species of the same genus produce this 
effect more quickly than the Camembert Penicillium. Some 
act at about the same rate as this one. ‘The reduction of the 
acidity of the cheese may clearly be attributed to these molds, 
but the study of the relations of many other molds to acids in- 
dicates that any of a large number of species might be equally 
or more useful for the accomplishment of this step in cheese 
ripening. If, therefore, these particular molds are essential to 
Camembert cheese ripening their special function must be 
sought in other steps of the process. 
I 
2. THE DIGHSTION OF CASHIN. 
The changes in firm sour curd which result in the production 
of the soft buttery or semi-liquid texture of the Camembert 
cheese present some very complex problems. These may be 
grouped as (1) the purely chemical questions which involve 
qualitative and quantitative analyses of the material at every 
stage; (2) the biological and physical questions which deal 
with the agents and conditions which produce these results and 
with the gross appearances of the final products whose descrip- 
tions do not depend upon detailed chemical analysis. 
1. The chemist. (Bul. 35, p. 29) describes the general course 
of ‘these processes and the nature and extent of changes as a 
digestion in which the insoluble or but slightly soluble com- 
pounds of casein found in sour curd are rendered almost com- 
pletely soluble in water. The details of the process and the 
data will appear in the report of the chemist later. 
2. ‘To determine what relations the molds might have to the 
chemical changes involved a great many cultures on different 
media. In some experiments the number of species used was 
large and the results acquired in that way a comparative value, 
- but in the more complicated trials the work was limited to those 
mentioned above. 
