xii, a, 2 Brill and Parker: Philippine Coconut Oil 109 



copra which has been attacked by molds or copra with milk 

 adhering to it has oxidasing enzymes present, and when such 

 copra is ground and pressed, some of this enzyme may be sep- 

 arated with the oil. If such enzymes were present, they would 

 in all probability have an important influence on the formation 

 of rancidity. 



The oils described in this article were examined for oxidizing 

 enzymes. No. 5 gave a faint test, No. 15 gave a fair test, and 

 No. 28 gave a strong test for peroxidaselike enzymes with 

 tincture of gum guaiacum and hydrogen peroxide. All the rest 

 responded negatively for oxidizing enzymes with these reagents. 

 No conclusion can be drawn concerning the cause for the pres- 

 ence of the enzymes in these samples and their absence in all 

 the others. No. 5 is a commercial sample of oil with a smoke- 

 like odor, which indicates that it was made from tapahan-dried 

 copra. In method of preparation and history it is very similar 

 to Nos. 1, 2, 3, 4, 5, and 7. No. 15 is an oil made from a machine- 

 dried copra. This sample is very similar to No. 14 in history. 

 No. 28, made from fresh copra, is pure and sweet and similar 

 in most respects to No. 27. The enzyme here must arise from 

 contamination from the milk of the nut. The activity of the 

 other two must arise from the molds that grew on the copra 

 before it was milled, the milling temperature not being high 

 enough to destroy their activity. 



Why only these three gave positive tests is difficult of expla- 

 nation. The color appeared in them only after the sample had 

 stood in contact with the reagent for a short time. 



Tests were made on the fresh coconut meat for lipase, but 

 we were unable to confirm the positive results reported by other 

 investigators. 17 Walker 18 reports no lipase or zymogen pres- 

 ent in the fresh meat, and our results are in accord with his. 

 Where the meat of the coconut is subjected to a comparatively 

 high temperature during the process of drying, the activity of 

 any enzyme doubtless would be greatly decreased if not totally 

 destroyed. But the hydrolysis of oils in the presence of mois- 

 ture undoubtedly takes place to an appreciable extent at rela- 

 tively low temperatures. In the experiments recorded by 

 Deming, where comparatively large amounts of mineral acids 

 were used "to activate the zymogen," we believe the acid alone 

 is sufficient to bring about the hydrolysis recorded by this observ- 



" De Kruff, Bull. Dept. Agr. Indes Neerl. (1906), 4, 8. Deming; H. G., 

 Phil. Agr. For. (1914), 3, 33. 



"Walker, H. S., This Journal, Sec. A (1908), 3, 111. 



