Oleum Cocois. Coconut Oil.
Related entry: Oils
Synonyms.—Oleum Cocois Nuciferae; Coprah Oil.
Coconut oil is a fat obtained by expression from the kernels of the coconut, the fruit of Cocos nucifera, Linn., and C. butyracea, Linn. (N.O. Palmeae), growing chiefly in Cochin and Ceylon. It occurs as a solid, white or pearl-white fat, of the consistence of lard, having a bland taste, and a peculiar but not unpleasant odour. Specific gravity, 0.903 at 100°; melting-point, 21° to 25°. Solidifies at 13° to 12°. On exposure to the air, the oil readily turns rancid, acquiring an unpleasant odour, and a strong acrid taste. It is readily saponified by the strong alkalies, and, from the fact that its soap is not easily precipitated by salt solution, is largely used in making "marine" soap. The high saponification number of the oil (258), and low iodine value (8 to 9.5) are characteristic. The solid fats may be separated from the liquid by cold pressure. The stearin is sometimes used as an adulterant of oil of theobroma.
Soluble in alcohol (1 in 2) at 60°, less soluble at ordinary temperatures, very soluble in ether, chloroform, and in carbon bisulphide.
Constituents.—The oil contains trimyristin and trilaurin, and in smaller proportions tripalmitin, tristearin, and triolein, besides the glycerides of the volatile caproic, caprylic, and capric acids. The free fatty acids vary from 5 to 17 per cent., or even more, according to the source of the oil.
Action and Uses.—Coconut oil is used as a lubricant in massage, as a dressing for the hair, and more especially in soap manufacture; after removal of the free acids it is largely used as a butter substitute. It has been recommended as an ointment basis on account of its ready absorption. It has been given internally as a substitute for cod-liver oil. A deodorised variety of coconut oil is prepared. Coconut stearin, melting at 28.81, is used as a suppository basis.
Dose.—8 to 16 grammes (2 to 4 drachms).