Oleum Amygdalae Expressum. U. S. (Br.) Expressed Oil of Almond.

Botanical name: 

Ol. Amygd. Exp. [Oil of Sweet Almond]

Related entry: Amygdala dulcis - Peach

"A fixed oil obtained from the kernels of varieties of Prunus Amygdalus Stokes (Fam. Rosaceae). Preserve it in well-closed containers, in a cool place." U. S. "Almond Oil is the oil expressed from the Bitter or Sweet Almond." Br.

Oleum Amygdalae Br.; Almond Oil; Oleum Amygdalae Dulcis, U. S. 1860; Oil of Sweet Almond; Huile d'Amande douce, Fr. Cod.; Huile d'Amandes, Fr.; Oleum Amygdalarum, P. G.; Mandelöl, G.; Olio di mandorle dolci. It.; Aceite de almendraa dulces, Sp.

This oil is obtained equally pure from sweet and from bitter almonds. In its preparation, the almonds, having been deprived of a reddish-brown powder adhering to their surface, by being rubbed together in a piece of coarse linen, are ground in a mill resembling a coffee-mill, or bruised in a stone mortar, and then pressed in canvas sacks between plates of iron slightly heated. The oil, which is at first turbid, is clarified by rest and filtration. Sometimes the almonds are steeped in very hot water, deprived of their cuticle, and dried in a stove, previous to expression. The oil is thus obtained free from color, but in no other respect better, while it is more likely to become rancid on keeping. Bitter almonds treated in this way impart an odor of hydrocyanic acid to the oil. Boullay obtained 54 per cent. of oil from sweet almonds. Munch gives 55.4 per cent. as the yield of the former, and 52 per cent. as that of the latter. (J. P. C; 4e ser., iii, 400.) These figures are not realized, however, in the ordinary expression methods. Schaedler (Technologie der Fette und Oele, 2te Auf., 532) gives 45 per cent. as the average obtained from the sweet almonds, and 38 per cent. from bitter almonds. Though sometimes expressed in this country from imported almonds, the oil is generally brought from Europe.

Properties.—It is "a clear, pale straw-colored or colorless, oily liquid, almost odorless, and having a bland taste. It is slightly soluble in alcohol, miscible with ether, chloroform, benzene, or petroleum benzin. Specific gravity: 0.910 to 0.915 at 25° C. (77° F.). The oil remains clear at -10° C. (14° F.), and does not congeal until cooled to nearly -20° C. (-4° F.) (olive or lard oil). Shake vigorously 2 mils of the oil with a mixture of 1 mil of fuming nitric acid and 1 mil of water; a whitish mixture is formed, which, after standing for several hours at about 10° C. (50° F.), separates into a solid white or nearly white mass and a slightly colored liquid (oil of peachor apricot kernels, yielding a red color, and sesame or cottonseed oil, yielding a brown color). Heat 10 mils of the Oil with 15 mils of an aqueous solution of sodium hydroxide (1 in 6) and 30 mils of alcohol on a water bath in a flask having a small funnel inserted in the neck, occasionally agitating the mixture until it becomes clear, then transfer the solution to a shallow dish and evaporate the alcohol on a water bath. The residue, when mixed with 100 mils of distilled water, produces a clear solution (paraffin oil). Add an excess of hydrochloric acid to this solution; a layer of oleic acid rises to the surface, which, when separated, washed with warm water and clarified by heating on a water bath, remains clear if cooled to 15° C. (59° F.) (various foreign oils). One volume of the oleic acid obtained in the last test, when mixed with 1 volume of alcohol, yields a clear solution, which at 15° C. (59° F.) does not deposit any fatty acids, nor become turbid upon the further addition of 1 volume of alcohol (distinction from olive, arachis, cottonseed, sesame, or other fixed oils). Saponification value: not less than 191 nor more than 200. Iodine value: not less than 93 nor more than 100." U. S.

From the statement of Braconnoit, it appears to contain 76 per cent. of olein and 24 per cent. of a mixture of palmitin and stearin.

According to H. Hager, the oils expressed from the large sweet and the smaller bitter almonds differ considerably, as shown by the elaidin test,—the former oil congealing rapidly, and almost completely, the latter about twelve hours later, and the smaller the bitter almond has been the more imperfectly the oil congeals. Only about one-third of the bulk congeals when the oil is from the small Oporto almonds.

Oil of almond may be used for the same purposes as is olive oil, and, when suspended in water by means of mucilage or the yolk of egg and loaf sugar, forms a pleasant emulsion, useful in pulmonary affections attended with cough.

Dose, one fluidrachm to one fluidounce (3.75-30 mils).

The Dispensatory of the United States of America, 1918, was edited by Joseph P. Remington, Horatio C. Wood and others.