THE PHILIPPINE | 
JOURNAL OF SCIENCE 
VoL. I FEBRUARY 15, 1906 No. 2 
THE KEEPING QUALITIES AND THE CAUSES OF 
RANCIDITY IN COCONUT OIL. 
By Hersert 8. WALKER. 
(From the Chemical Laboratory, Bureau of Science.) 
In almost every work on fats and oils, coconut oil is cited as being 
especially prone to become rancid. Lewkowitsch! states that, when 
fresh, it possesses a bland, pleasant taste and odor, but that on standing 
it quickly becomes rancid. Samples analyzed by him contained from 
5 to 25 per cent of free acid. Schestakoff? says that pure coconut 
oil shows an acid value (milligrams of caustic potash) of from 2 to 5. 
On standing under abnormal conditions, this may in one year rise to 
60 or 70. 
Coconut oil is in enormous demand as the basis of edible products such 
as “vegetable butter,” etc., and therefore it is of the utmost importance 
to be able to produce an oil which, as nearly as possible, is free from 
fatty acids, rancid odor or taste, and which at the same time may be 
shipped without fear of deterioration. 
The experiments to be described were undertaken with the view of 
discovering the conditions which induce a rapid deterioration of coconut 
oil, and, if possible, of ascertaining a means of improving its keeping 
qualities. In the course of this work it was noticed that the oil does 
not change with as great rapidity as is generally believed to be the case. 
The ordinary commercial oil, bought in Manila, contains from 5 to 10 
* Lewkowitsch: Chemical Analysis of Oils, Fats, and Wases. 
* Schestakoff: Uber den Gehalt an freien Fettsiiuren natiirlicher Fette und Ole. 
Chem. Rev. Fett. u. Harz. Ind. 9, 180. 
38151 : 117 
