J. R. FuRLONa 139 



fatty acids of other oil seed cakes. The results have however led to the 

 conclusion that the objection to palm kernel cake lies in the initial pro- 

 duction of fatty acids. On the other hand it has been shown definitely 

 that 2)alm kernel oil itself is not more readily decomposed into fatty 

 acids than the oils of other feeding cakes investigated in these experi- 

 ments. 



Calder has stated that heating the moistened cake for haif-an-hour 

 at 70° C. would completely destroy the lipase and prevent rancidity of 

 the cake from this source. The present investigation has shown that 

 palm kernel lipase, whether in the kernels or in the cake and meal, is 

 very resistant to heat, and capable of surviving to an appreciable e.xtent 

 four hours' exposure to a temperature of 97° C. in a moist state or two 

 hours' exposure at 120° C. in a dry condition. To render the lipase in 

 the cake inactive vigorous boiHng with water for one hour was found to 

 be necessary. 



In view of the great resistance of the lipase to heat it is not practicable 

 by this agency to render the lipase in the cake inactive before leaving the 

 factory, and even if the lipase in the cake were rendered inactive the 

 latter would be subject to deterioration by moulds and bacteria if allowed 

 to become damp. It is therefore necessary in any case to preserve palm 

 •kernel cake and all other feeding cakes in a dry condition, and these 

 experiments have shown that palm kernel cake may be kept for eighteen 

 months in a dry condition without acidity or rancidity developing. At 

 the end of this period the cake had not deteriorated, and was in sweet 

 condition. On the other hand the most favourable conditions for the 

 action of the lipase and the development of activity are warmth and 

 excess of moisture. 



Experimental. 



Preliminary experiments showed that the amount of acidity developed 

 by the cake was very small. It was therefore decided to investigate palm 

 kernels themselves, in which greater activity was to be expected, in order 

 to determine the conditions most favourable for the production of 

 acidity. 



The method of investigation consisted in maintaining the prepared 

 mixture at a given temperature for a certain number of hours in a water 

 bath and determining the rise in acidity. The mixture, to which 2 c.c. 

 of toluene had been added to prevent bacterial action, was contained 

 in a flask plugged with cotton wool. The meals were finely ground and 

 the kernels reduced to a pulp by grinding. The mixture was thoroughly 



