70 The Fermentation of Cacao 
results at the same time, has still to be decided, 
but that is outside the present discussion. : 
The cotyledons also turn brown, and the 
bitter taste is removed if the green cacao, freed 
from the surrounding pulp, is ground into a 
pulp or jelly. This treatment also kills the 
germs, but leaves the enzymes intact. At 
this point it will not be out of the way to 
compare the behaviour of the sloe (Prunus 
spinosa), which has a strong resemblance to 
cacao in certain points. Left to itself the sloe 
‘has such a bitter taste that it is unfit to eat, 
but after a frost the pulp cells die off and the 
enzymes make their action felt, with the result 
that the acidity disappears, and the fruit 
becomes palatable. Here, again, the reduc- 
tion and final disappearance of the acidity 
is also accompanied by the appearance of a 
brown colouration which is likewise caused by 
the oxidation of the tannic: contents (perhaps 
after. a previous separation of the glucoside). 
The supposition that an oxydase plays a part 
in bringing about the fermentation of cacao 
beans (by an oxydase is meant an enzyme 
which hastens oxidation) has been stated more 
than once, and that it is so can be easily 
proved. The oxidation of the tannic sub- 
stances in other fruits containing tannin is 
attributed to the assistance of oxydases. If 
cacao beans are heated in water at 75° C. and 
then ground, no change of colour and no 
reduction in the bitter taste of the mass takes 
