Almond

ALMOND, the dried fruit (stone fruit) of the tree Araygdalus communis L. (M. ordinary) (according to VII Pharmacopoeia Prunus amygdalus Stokes—M. real) of the family Rosaceae (Rosa-seeae), growing along the coast of the Mediterranean Sea, in the Crimea, and in the southern USSR. In trade, seeds are available: sweet M. (from Amygdalus comm. L., var. dulcis D. C. and from Prunus amygdalus Stokes), peeled or in shells (almond nut, dessert M., German Knack- or Krack-mandeln), and bitter M. (from Amygdalus comm. L., var. amara D. C.). Bitter M. differs from sweet M. in taste (contains bitter glycoside amygdalin—see). Seeds of sweet M. (Semina Amygdali dulcis) are ovoid, pointed at the more flattened end, cream-white, covered with a light-brown rough shell. Length—2.5–4.5 cm (rarely), width—up to 2.5 cm, thickness—0.5–1 cm. At the wide end of the seed is a round dark-gray spot (chalaza), from which to the hilum at the pointed end go the seed suture and branching vascular bundles. The kernel consists of two seed lobes with the radicle of the embryo at the pointed end. Dimensions of seeds of bitter M. (Semina Amygdali amarae): length—2 cm, width—about 1.5 cm, thickness—up to 1 cm. For medicines, kernels peeled of their shells (Sem. Amygd. excorticata, s. deglupta) are used; for this purpose M. is poured with hot water, after which the shell is easily removed. Composition of almond seed: fatty oil (Oleum Amygdalarum—almond oil; according to VII Pharmacopoeia it is obtained equally from both sweet and bitter M.)—from 40% to 55%; sugar (cane and glucose)—up to 10%; mucus—about 3%, protein substances—about 20% (among them soluble in water and alkalis but precipitated by acids—conglutin—plant casein), asparagine (see), emulsin, and ash (about 3%), containing sulfates and phosphates of potassium, sodium, calcium, magnesium, and iron. Starch is absent. In bitter M. up to 3% amygdalin is contained. Moisture of air-dry M.—about 3.5%. Almond oil, fatty, is obtained by cold pressing of selected, ground seeds of M. Almond oil consists of almost pure triolein ₃H₅(O. COC₁₇H₃₃)₃, with a slight admixture of trilinolein ₃H₅(O. COC₁₇H₃₁)₃, phytosterin (traces), etc. Constants of almond oil—see Fats (table). Almond oil is soluble in alcohol (according to VII Pharmacopoeia 1:60), easily in ether, chloroform, benzine, etc., insoluble in water. When mixed with half its volume of strong (sp. gr. 1.4) nitric acid in the presence of metallic mercury or copper shavings, the oil solidifies within half an hour into a dense, white (sometimes slightly pinkish or yellowish) mass (elaidin test); freezing point is below -15°. Seeds of M. are used in medicine only peeled; from sweet M. emulsions (almond milk, Emulsio Amygdalarum) are prepared by grinding with water, usually in a ratio of 1:10. The emulsion is used as a slightly enveloping and absorbing substance; its action is calculated on the presence of mucus and fatty oil. Emulsion of fatty oil (Emulsio oleosa, Emulsio O. Amygdalarum) is prepared from 2 parts almond oil, 1 part gum arabic, and 17 parts water; the action is the same, with the sole difference that in the emulsion from the seed contains emulsin, and therefore in the case of adding, for example, amygdalin to the emulsion from oil it will remain unchanged, while in the emulsion from seeds it will decompose with conversion into glucose and benzaldehyde cyanohydrin (nitrile of almond acid), and partially further into benzoic aldehyde (bitter almond essential oil) and hydrocyanic acid. The marc remaining after pressing almond oil is ground and extracted for the final obtaining of oil with volatile solvents (e.g., carbon tetrachloride). The extracted marc (meal) is processed into almond bran (Placenta Amygdalar., or Farina Amygdalarum) by grinding into a fine powder. Commercial almond bran contains an admixture of borax, soap, sometimes talc, starch, or flour of various cereals, and fragrances. The cosmetic significance of almond bran is doubtful; they count on the action of residual oil, and mainly on the action of admixtures (borax, etc.). From the marc of bitter M., amygdalin (see) is extracted or bitter almond water (see) is distilled off. The principle of the latter process consists in the fact that amygdalin contained in bitter almond, under the influence of emulsin, is split into nitrile of almond acid and glucose; upon distillation, glucose remains in the distillation flask, and benzaldehyde cyanohydrin is distilled, partially decomposing into benzoic aldehyde (essential oil of bitter M.) and hydrocyanic acid, which is also distilled with water vapor: .O-CrII_lu0₄-O-C₆Hii0₅.3H₂O-> c₆н₅сн( ^XCN

amygdalin .OH -> C«11.3CИ(

-b2C₆Hi20₆ + II_£0; benzaldehyde cyanohydrin glucose OH C₆И₅CH<_ ->C_eH₅CHO+HCN. ⁴CN benzaldehyde The distillate is collected in a flask containing alcohol; the latter arrests the decomposition of benzaldehyde cyanohydrin, as well as the transition of hydrocyanic acid into formic ammonium salt (HCN+2H₂0 = HCO.ONH₄) and promotes the preservation of benzaldehyde in dissolved form, which is insoluble in pure water. Upon distillation without placing alcohol in the receiver, the distillate separates into two layers, the lower of which represents the essential oil of bitter almond (Oleum Amygdal. aether.) with an admixture of hydrocyanic acid. Bitter M. is not applied in medicine directly due to the fluctuating content of amygdalin in it.

I. Obergard. Poisonings by bitter M. are rare and occur in forensic medicine as an accident or for the purpose of suicide. In one grain of bitter M. about 1 mg of hydrocyanic acid is contained, although the amount of it fluctuates depending on the variety of M. and the method of processing. In one case, the death of a 3-year-old boy followed 1 hour after the intake of 7–10 pieces of bitter almonds, and in another—an adult subject was poisoned by two handfuls of bitter almonds, but was saved. At autopsy, in addition to signs of poisoning by hydrocyanic acid (see), a certain amount of chewed M. is found in the stomach. In place of bitter M., kernels of apricot stones (Semina Pruni armenia-cae) or peaches (Semina Pruni persicae) can be admitted as containing amygdalin; also the fatty oils of seeds of almonds, apricots, and peaches are almost identical. Due to low acidity and the absence of dense fatty acids, these oils are especially willingly used for the preparation of oil solutions for injections (camphor, mercury, etc.).