November, 1908.] 



417 



Oils and Fats. 



Colourless Oil. 

 Coconut oil is also considerably lighten- 

 ed in colour by the above treatment, 

 but in no sense can it be considered as a 

 colourless oil. To remove the last traces 

 of colouring matter from a vegetable 

 oil is much more difficult than the des- 

 truction of the rancid odour, and in 

 order to accomplish this completely it is 

 necessary to subject the refined oil to 

 some mild bleaching action which does 

 not introduce harmful ingredients which 

 would be difficult of subsequent removal. 

 Of the many well-known methods of 

 bleaching proposed for general use, 

 hydrogen peroxide seems to be most 

 favourable in this regard as it is easy of 

 application, and at its present price is 

 not prohibitive. Sufficient dilute alkali 

 should be added to neutralize any 

 mineral acid it may contain, and a slight 

 excess favours the action of this reagent, 

 at the same time having no saponifying 

 action. Next in order of suitability is a 

 dilute solution of chloride of lime 

 slightly acidified with acetic acid. If 

 the addition of acid and the temperature 

 of the bleaching are carefully controlled, 

 the chance of injury to the oil by free 

 chlorine is a minimum, and the result is 

 a pure, water-white product. — Indian 

 Trade Journal, 24th Sept., 1908, p. 285. 



NOTES ON THE SPROUTING COCO- 

 NUT, ON COPRA, AND ON 

 COCONUT OIL. 



(By H. S. Walker, in Philippine Jour- 

 nal of Science, III, A. 1908, p. 111.) 



Abstracted by J. C, Willis. 



1. Enzymes. — Experiments were car- 

 ried on to determine if the coconut, like 

 the castor-oil and other oil seeds, 

 contains a fat-splitting enzyme. No 

 trace of such a body could be discovered, 

 and the cause of the destruction of the 

 fat in the growing nut must therefore 

 be sought elsewhere. 



2- Changes in the Sprouting Nut. — 

 " Oil is lost by the meat ; it is not taken 

 up as such by any other portion of the 

 nut, but is either burned to furnish en- 

 ergy for the growing plant oi is split up, 

 being transformed by progressive syn- 

 thesis into sugar and finally to cellulose." 



3. Copra. — The moulds which grow 

 on copra were found to have the pro- 

 perty of hydrolyzing and destroying 

 fat ; it is, therefore, a direct loss of oil 

 if these be suffered to grow. Bacteria, 

 which also grow, do not reduce the oil 

 but produce a sour smell and disin- 

 tegrate the meat. 



4. Production of Acid in Oil.— The 

 deterioration of a freshly prepared oil is 

 due to several causes. Molds destroy it 

 after it is expressed, but this may be 

 checked by filtration, preferably after 

 heating to the boiling point of water to 

 destroy moulds and enzymes formed by 

 them. Afterwards oxidation by the air 

 sets in, and the oil should therefore be 

 stored in full receptacles, impervious to 

 air. Heat also has some effect. 



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