96 PHILIPPINE RESINS, GUMS, AND OILS 
and that beyond this period, which coincides with the time that‘ 
the sprout makes its appearance, there is a decided decrease in 
the above constituents. 
The quality and value of coconut oil depend largely upon the 
condition of the copra at the time of milling. Copra which has 
not been sufficiently dried becomes moldy. The molds tend to 
decompose, or hydrolyze the fats in the copra, with the result 
that the oil, after expression, contains free, fatty acids, becomes 
rancid quickly, and acquires a bad odor. Walker made a large 
number of experiments to determine the conditions which induce 
this deterioration and the methods by which it could be pre- 
vented. He found that, ordinarily, commercial copra contained 
from 9 to 12 per cent of moisture and that this amount was 
very favorable for the growth of molds. Most of the free acids 
and the accompanying bad odor and taste which are present in 
coconut oil are produced in the copra itself. Walker found that 
no organisms grew, and that there was no change of acidity, in 
a sample of copra containing 4.7 per cent of moisture. The 
remedy is to dry the copra until it contains no more than 5 per 
cent of moisture, which prevents the growth of mold; and to 
express the oil as soon as possible, thereby avoiding long storage 
in a warm, moist atmosphere. He says that the copra should 
be fresh and be prepared under the best possible conditions of 
drying, and that the oil should be thoroughly dried and filtered 
until absolutely clear. Under these conditions it should be cap- 
able of shipment or storage without noticeable deterioration. 
He believed, contrary to many statements, that the keeping 
qualities of coconut oil prepared in a pure state were superior 
to those of most other vegetable fats and oils. When sufficient 
sugars and albuminoids are left in the oil, if, in other words, , 
it is not properly filtered, molds which have been pressed out 
with the oil or, in the case of hot-pressed oil, which enter the 
freshly prepared oil, cause a rapid splitting of the fat and an 
increase in acidity. 
Brill, Parker, and Yates * confirmed Walker’s conclusions, 
that the deterioration of copra is due largely to molds and not to 
bacteria, since a moisture content sufficiently high to favor bac- 
terial growth is not found ordinarily in copra and, moreover, 
bacteria cause scarcely any loss even under conditions most 
favorable for their growth. These writers found four molds 
cecurring upon coconut meat and moldy copra. The spore 
masses of the four molds differ considerably in color and are , 
~ 

* Brill, H. C., Parker, H. O., and Yates, H. S., Copra and coconut oil. 
Philippine Journal of Science, Section A, Volume 12 (1917), page 55. 
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