46 EUITOIUAL. 



application and, as general!}' practiced, removes all of the susjiended 

 foreign matter and most of the soluble impurities, producing a perfectly 

 clear, light, amber oil of sufficient purity for soap stock, but it falls short 

 of being completely free from odor and color. Therefore, further refilling 

 constitutes the only known means of producing an odorless and colorless 

 product suitable for alimental or cosmetic purposes. The removal of the 

 last traces of odor and color. from coconut oil presents many difficulties 

 in the way of subsequent clarification and risk of loss of oil and the 

 methods of procedure are necessarily limited to the use of such chemical 

 reagents as are harmless or are easily removed. In general, refining proc- 

 esses may be conveniently divided into (1) acid and (8) alkaline treat- 

 ments, the former has not proved applicable for the production of oils 

 ~ for edible, cosmetic or lubricating purposes, because of the poisonous 

 nature and otherwise^ harmful action of mineral acids. The alkaline 

 process makes use of the hydrates or carbonates of the fixed alkalies, 

 ammonia, caustic lime or magnesia, with or without the aid of heat. The 

 efficiency of an alkaline treatment depends upon incomjjlete saponification, 

 whereby the free, volatile, fatty acids, which are responsiljle to a large 

 measure for the characteristic odor of coconut oil, are first neutralized and 

 precipitated as a salt of whichever alkali is employed. If the alkali be 

 added in excess of the amount necessary to neutralize the free acids and 

 the oil is steamed or otherwise heated, then the neutral glycerides — that 

 is, the oil itself — suffers partial decomposition and goes to augment 

 the amount of soaps fonned. Therefore, unless any alkaline treatment 

 of a vegetable oil is carefully regulated, both as regards the amount of 

 alkali used and the temperature employed, low yields of purified oil are 

 obtained. All of the residues or "foots" go to form soap stock, hence the 

 advisability is apparent of employing this process in conjunction with a 

 market for the by-product. The main points to note in connection with 

 refining by means of allcalies are, first, the minimum quantity of alkali 

 necessary to effect the purification and, second, the right concentration 

 of caustic lye which is unfavorable to the formation of emulsions. The 

 minimum quantity of alkali can be determined accurately by testing the 

 acidity of a small sample of the oil to l)e refined, or by the cut and 

 dried methods of practical experience. 



Ordinary commercial grades of coconut oil collected on the Manila 

 market contain from 1 to 10 per cent of free fatty acids calculated as 

 oleic acid, and these percentages require approximately 0.15 to 1.5 parts, 

 respectively, of caustic soda per 100 parts of oil. The caustic soda may 

 be added to the oil either in the solid state with suljsequent addition of 

 water, or better, in the form of a caustic liquor previously prepared. 

 The stronger the caustic liquor used the less the tendency to emulsion 

 formation and the more rapid and complete the action, if proper 

 mechanical devices for thoroughlv mixing a strong Ive with the oil are 



