Garlic
(Allium sativum) is a bulbous perennial food plant of the family
Alliaceae. The word comes to us from Old English gārlēac, meaning "spear
leek".
The bulb has a strong and characteristic odor and an acrid taste, and
when pure yields an offensively smelling oil, essence of garlic,
identical with allyl sulphide (C6H10S2). Garlic is widely used in many
forms of cooking for its strong flavour, which is considered to enhance
many other flavours. Depending on the form of cooking and the desired
result, the flavour is either mellow or intense. It is often paired with
onion and tomato. When eaten in quantity, garlic may be strongly evident
in the diner's sweat the following day. The well-known phenomenon of
"garlic breath" can be alleviated by eating fresh parsley and this is
included in many garlic recipes. Because of its strong odor, garlic is
sometimes called the "stinking rose".
Cultivation and plant structure
Because of its wide cultivation, the
origins of garlic are uncertain; it has been traced to both southwest
Siberia and Sicily, where it grows wild. It is related to onions and
lilies, and cultivated in the same manner as the shallot. The
domesticated garlic plant does not produce seeds, but is grown from
bulbs. These bulbs, whose segments are usually called "cloves" by cooks,
are the part of the plant most commonly eaten, though some cooks also
use the early spring shoots. These shoots are often pickled in Russia
and states of the Caucasus and eaten as an appetizer. A common error of
beginning cooks is to misinterpret the word "clove" as meaning the
entire garlic bulb, rather than one of its segments, thereby wildly
exaggerating the amount of garlic in a recipe.
The garlic plant has long, narrow, flat, obscurely keeled leaves. The
bulb has a flaky outer layer of skin like that of an onion. Inside are
10 or 12 cloves, or smaller bulbs. From these, new bulbs can be procured
by planting out in late winter or early spring.
Following growing instructions:
Plant the individual cloves from a garlic plant in drills of 5 cm (2 in)
and 15 cm (6 in) apart. Ideal soil pH is in the 6.2 to 6.8 range.
Garlic grows best in hot wet
conditions, but try it all year round. It is pretty hardy and will live
through frosts.
Ensure that the growing area is weed free.
Garlic likes water; in a hot climate it may need to be watered daily. If
the shoots look dry then it is a sign that the plant needs a 'drink'.
Garlic is ready to harvest about four months after it has been sown. At
this point the foliage will lose its colour and die back. Dig up the
bulbs with a fork to avoid damaging them.
The percentage composition of the bulbs is given by E. Solly (Trans.
Hon. Soc. Loud., new ser., iii. p. 60) as water 84.09%, organic matter
13.38%, and inorganic matter 1.53% - that of the leaves being water
87.14%, organic matter 11.27% and inorganic matter 1.59%.
Culinary use
Garlic is most often used as a
seasoning or a condiment, and is believed by some to have some medicinal
value[1], notably against hypertension. When crushed or finely chopped
it yields allicin, a powerful antibiotic and anti-fungal compound. It
also contains alliin, ajoene, enzymes, vitamin B, minerals, and
flavonoids.
Allicin has been determined to be the agent behind the spiciness of raw
garlic. This chemical opens thermoTRP (transient receptor potential)
channels which are responsible for the sense of noxious heat in foods.
The process of cooking garlic removes allicin, thus mellowing its
spiciness. (Macpherson et al., 2005)
Medicinal use
Garlic is claimed by some to have many
significant medicinal benefits, but there has been no demonstration of
the effects of garlic that meets commonly accepted scientific standards.
In modern naturopathy, garlic is used as a treatment for intestinal
worms.
Pliny the Elder, in his Natural History, (N.H. xx. 23) gives an
exceedingly long list of complaints in which it was considered
beneficial. Dr. T. Sydenham valued it as an application in confluent
smallpox, and, says Cullen (Mat. Med. ii. p. 174, 1789), found some
dropsies cured by it alone. Early in the 20th century, it was sometimes
used in the treatment of pulmonary tuberculosis or phthisis.
Garlic cloves continue to be used by aficionados as a remedy for
infections (especially chest problems), digestive disorders, and fungal
infections such as thrush. They are claimed to be an effective long-term
remedy for cardiovascular problems reducing excessive blood cholesterol
levels, atherosclerosis, the risk of thrombosis, and hypertension but
these claims are disputed as there has been no clinical trial that has
demonstrated any such benefits. Whole cloves used as suppositories are
sometimes used as a home remedy for Bacterial Vaginosis. Garlic is also
alleged to help regulate blood sugar levels, and so can be helpful in
late-onset diabetes, though people taking insulin should not consume
medicinal amounts of garlic without consulting a physician. In such
applications, garlic is best used fresh.
Components
Phytochemicals
- Allicin
- Beta-carotene
- Beta-sitosterol
- Caffeic acid
- Chlorogenic acid
- Diallyl-disulfide
- Ferulic acid
- Geraniol
- Kaempferol
- Linalool
- Oleanolic acid
- P-coumaric acid
- Phloroglucinol
- Phytic acid
- Quercetin
- Rutin
- S-allyl cysteine
- Saponin
- Sinapic acid
- Stigmasterol
Nutrients
- Calcium
- Folate
- Iron
- Magnesium
- Manganese
- Phosphorus
- Potassium
- Selenium
- Zinc
- Vitamin B1 (Thiamine)
- Vitamin B2 (Riboflavin)
- Vitamin B3 (Niacin)
- Vitamin C
History
From the earliest times garlic has been
used as an article of diet. It formed part of the food of the Israelites
in Egypt (Numb. xi. 5) and of the labourers employed by Cheops in the
construction of his pyramid. Garlic is still grown in Egypt, where,
however, the Syrian is the kind most esteemed (see Rawlinson's
Herodotus, 2.125).
It was largely consumed by the ancient Greek and Roman soldiers, sailors
and rural classes (cf. Virg. Ed. ii. II), and, as Pliny tells us (N.H.
xix. 32), by the African peasantry. Galen eulogizes it as the "rustic's
theriac" (cure-all) (see F Adams's Paulus Aegineta, p. 99), and
Alexander Neckam, a writer of the 12th century (see Wright's edition of
his works, p. 473, 1863), recommends it as a palliative of the heat of
the sun in field labor.
Garlic was rare in traditional English cuisine (though it is stated to
have been grown in England before 1548), and a much more common
ingredient in southern Europe. Garlic was placed by the ancient Greeks
on the piles of stones at cross-roads, as a supper for Hecate
(Theophrastus, Characters, The Superstitious Man); and according to
Pliny, garlic and onions were invoked as deities by the Egyptians at the
taking of oaths. The inhabitants of Pelusium in lower Egypt, who
worshipped the onion, are said to have held both it and garlic in
aversion as food.
Classification
Classification of culinary garlic can
be complex. The broadest division is into "hardneck" and "softneck"
types; very broadly speaking, hardnecks have more intense flavors--they
are more closely related to their wild ancestor--but lesser storage
capabilities, while conversely softnecks are excellent "keepers" but
often milder (those are broad-brush simplifications with numerous
exceptions and half-exceptions.) Within those two types, there are
usually felt to be three subdivisions of hardnecks and two of softnecks.
One scheme, with some flavor notes from a commercial grower, is this:
- Hardneck:
- Rocambole - rich, full-bodied
flavor
- Porcelain - much like rocambole
- Purple Stripe - these often win
"baked-garlic" taste tests:
- Purple Stripe per se
- Glazed Purple Stripe
- Marbled Purple Stripe
- Softneck:
- Artichoke - "milder" flavors:
- Artichoke per se
- Asiatic
- Turban
- Silverskin:
- Silverskin per se - the familiar
supermarket garlic
- Creole
The term "wild garlic" is now used to
refer to ramsons (Allium ursinum). In North America, "wild garlic" or
"crow garlic" is (Allium vineale), and along with "wild onion" (also
known as "meadow garlic" or "wild garlic") (Allium canada) are common
weeds in fields.
Preservation
The types differ not only in culinary
qualities, but in storage potential. Under good storage conditions,
which are not hard to achieve (room temperature and medium to low
humidity), one can hope for these results:
Asiatic and Turban types: a few months
Rocambole and Purple Stripe types: 6 months
Porcelain and Artichoke types: 8 to 10 months
Silverskin (including Creole) types: up to a full year
Rocamboles, however, have a tendency to dehydrate in storage under dry
conditions (less than about 50% humidity).
The bulbs are best preserved hung in a dry place. If of fair size, four
to six of them weigh about 1 lb (0.5 kg). To prevent the plant from
running to leaf, Pliny (Nat. Hist. xix. 34) advised bending the stalk
downward and covering with earth; seeding, he observes, may be prevented
by twisting the stalk. (By "seeding", he mostly likely means the
development of small, less potent bulbs.)
Caution
- Garlic is very "heating" and can
irritate the stomach.
- While culinary quantities are
generally safe, do not take garlic in therapeutic doses during
pregnancy and lactation; it can cause digestive problems such as
heartburn, and babies may dislike the taste in breast milk.
- Garlic's strong aromatic compounds
are excreted via the lungs and the skin; eating fresh parsley may
eliminate odor on the breath.
- The medicinal effects of taking
garlic long-term are largely unknown, and no FDA approved study has
been performed.
The medicinal effects of taking garlic
long-term are largely unknown, and no FDA approved study has been
performed.
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