dulcisMill., andA. communisL., in addition to
the above synonyms. It grows to a height of
about 7 m and has several varieties; two of
them, var. dulcis and amara, yield sweet
and bitter almonds, respectively. The tree is
native to western Asia and is now extensively
cultivatedintheMediterraneancountriesandin
California. The fruit is botanically classified as
a drupe (same as peach or plum), except that its
outer portion is leathery, not fleshy and edible
like the peach; the almond is its seed.
Sweet almonds are used as food, but bitter
almonds are not; this is due to the presence of
amygdalin in bitter almonds that can be hy-
drolyzed to yield deadly hydrocyanic acid
(HCN).
Two major types of products are derived
from the almond, namely a fixed oil and a
volatile oil. The fixed oil is commonly called
almond oil, expressed almond oil, or sweet
almond oil; it is made from both sweet and
bitter almonds by pressing the kernels. It does
not contain benzaldehyde or HCN.
Thevolatile oil is called bitter almond oil. It
is obtained by water maceration and subse-
quent steam distillation of the expressed and
partially deoleated bitter almonds or kernels
of otherPrunusspecies that contain amygda-
lin; these species include apricot (P. armenia-
caL.), peach (P. persica(L.) Batsch.), and
plum (P. domesticaL.). During maceration,
the enzyme (emulsin) present hydrolyzes the
amygdalin into sugar, benzaldehyde, and
HCN, the last two being distilled by steam.
Sweet almond does not yield a volatile oil.
CHEMICAL COMPOSITION
Both sweet and bitter almonds have similar
chemical composition and contain 35–55%
fixed oil (MERCK).1,2The only difference ap-
pears to be the presence of amygdalin (3–4%)
in bitter almond and its absence or presence in
trace amounts in sweet almonds.3,4Other
constituents reported to be present in sweet
and/or bitter almonds include protein
(18–25%); emulsin; prunasin (0.005% in
bitter almond);^5 daucosterol, and other sterols
(e.g., sitosterol, citrostadienol, 24-methylene-
cycloartanol);2,6calcium oxalate;^7 tocopher-
ols (mostlya);8,9trace amounts of vitamins
A, B complex, and E; and amino acids, includ-
ingglutamicacid,asparticacid,andarginine.^10
Expressed almond oil has been reported to
contain 53 individual triglycerides of which
triolein and dioleolinolein make up 32% and
33%, respectively;^11 fatty acids present in-
clude oleic (66–72%), linoleic (18–22%), pal-
mitic (5.7–7.9%), stearic, lauric, myristic, and
palmitoleic acids (MERCK).7,12,13
Bitter almond oil contains mostly benzal-
dehyde (95%) and HCN (2–4%). For food and
flavor uses the HCN is removed, and the
resulting oil is almost pure benzaldehyde.
Almonds also contain varying amounts
(3.11–5.25%) of soluble nonreducing sugars
(sucrose, raffinose, and stachyose), depending
on the variety.14–16PHARMACOLOGY AND BIOLOGICAL
ACTIVITIESThe results of a clinical study in men and
women suggest that combined with a heart-
healthy diet, the addition of 100 g of dry-
roasted or raw almonds per day may signifi-
cantly lower LDL cholesterol.^17
Expressed almond oil has emollient, de-
mulcent, and mildly laxative properties. It is a
weak antibacterial. While easily absorbed and
digested orally, it is slowly absorbed through
intact skin.^10 Based on prevalent data, almond
oil and almond meal are nonirritating and
nonsensitizing to the skin and are considered
safe for cosmetic use.^10
Bitter almond oil, containing 2–4% HCN,
is poisonous; and fatal poisoning of an adult
after taking 7.5 mL has been reported.
Bitter almond oil, FFPA (free from prussic
acid, outdated term for HCN), can be
regarded as pure benzaldehyde; it has anti-
peptic, local anesthetic, and antispasmodic
properties; it also has narcotic properties at
high doses; ingestion of 50–60 mL can be
fatal due to central nervous depression with
respiratory failure (GOSSELIN).^1822 Almonds