The almond (''Prunus amygdalus'',
syn. ''Prunus dulcis'') is a species of tree native to
Iran
Iran, officially the Islamic Republic of Iran, and also called Persia, is a country located in Western Asia. It is bordered by Iraq and Turkey to the west, by Azerbaijan and Armenia to the northwest, by the Caspian Sea and Turkmeni ...
and surrounding countries,
including the
Levant
The Levant () is an approximate historical geographical term referring to a large area in the Eastern Mediterranean region of Western Asia. In its narrowest sense, which is in use today in archaeology and other cultural contexts, it is eq ...
.
The almond is also the name of the edible and widely cultivated
seed
A seed is an embryonic plant enclosed in a protective outer covering, along with a food reserve. The formation of the seed is a part of the process of reproduction in seed plants, the spermatophytes, including the gymnosperm and angiospe ...
of this tree. Within the genus ''
Prunus
''Prunus'' is a genus of trees and shrubs, which includes (among many others) the fruits plums, cherries, peaches, nectarines, apricots, and almonds.
Native to the North American temperate regions, the neotropics of South America, and the p ...
'', it is classified with the
peach
The peach (''Prunus persica'') is a deciduous tree first domesticated and cultivated in Zhejiang province of Eastern China. It bears edible juicy fruits with various characteristics, most called peaches and others (the glossy-skinned, non-fu ...
in the subgenus ''Amygdalus'', distinguished from the other subgenera by corrugations on the shell (
endocarp
Fruit anatomy is the plant anatomy of the internal structure of fruit. Fruits are the mature ovary or ovaries of one or more flowers. They are found in three main anatomical categories: aggregate fruits, multiple fruits, and simple fruits. Agg ...
) surrounding the seed.
The fruit of the almond is a
drupe
In botany, a drupe (or stone fruit) is an indehiscent fruit in which an outer fleshy part (exocarp, or skin, and mesocarp, or flesh) surrounds a single shell (the ''pit'', ''stone'', or '' pyrena'') of hardened endocarp with a seed (''kernel'') ...
, consisting of an outer hull and a
hard shell with the seed, which is not a
true nut. ''Shelling'' almonds refers to removing the shell to reveal the seed. Almonds are sold shelled or unshelled.
Blanched almonds are shelled almonds that have been treated with hot water to soften the
seed
A seed is an embryonic plant enclosed in a protective outer covering, along with a food reserve. The formation of the seed is a part of the process of reproduction in seed plants, the spermatophytes, including the gymnosperm and angiospe ...
coat, which is then removed to reveal the white
embryo
An embryo is an initial stage of development of a multicellular organism. In organisms that reproduce sexually, embryonic development is the part of the life cycle that begins just after fertilization of the female egg cell by the male spe ...
. Once almonds are cleaned and processed, they can be stored over time. Almonds are used in many food cuisines, often featuring prominently in desserts, such as
marzipan
Marzipan is a confectionery, confection consisting primarily of sugar, honey, and almond meal (ground almonds), sometimes augmented with almond oil or extract.
It is often made into Confectionery, sweets; common uses are chocolate-covered marzi ...
.
The almond tree prospers in a moderate
Mediterranean climate
A Mediterranean climate (also called a dry summer temperate climate ''Cs'') is a temperate climate sub-type, generally characterized by warm, dry summers and mild, fairly wet winters; these weather conditions are typically experienced in the ...
with cool winter weather. California produces over half of the world's almond supply. Due to high acreage and water demand for almond cultivation, and need for
pesticide
Pesticides are substances that are meant to control pests. This includes herbicide, insecticide, nematicide, molluscicide, piscicide, avicide, rodenticide, bactericide, insect repellent, animal repellent, microbicide, fungicide, and lampri ...
s, California almond production may be unsustainable, especially during the persistent drought and heat from
climate change
In common usage, climate change describes global warming—the ongoing increase in global average temperature—and its effects on Earth's climate system. Climate change in a broader sense also includes previous long-term changes to E ...
in the 21st century.
Droughts in California
The historical and ongoing droughts in California result from various complex meteorological phenomena, some of which are not fully understood by scientists.
Drought is generally defined as “a deficiency of precipitation over an extended peri ...
have caused some producers to leave the industry, leading to lower supply and increased prices.
Description
The almond is a
deciduous
In the fields of horticulture and Botany, the term ''deciduous'' () means "falling off at maturity" and "tending to fall off", in reference to trees and shrubs that seasonally shed leaves, usually in the autumn; to the shedding of petals, aft ...
tree growing to in height, with a trunk of up to in diameter. The young
twig
A twig is a thin, often short, branch of a tree or bush.
The buds on the twig are an important diagnostic characteristic, as are the abscission scars where the leaves have fallen away. The color, texture, and patterning of the twig bark are ...
s are green at first, becoming purplish where exposed to sunlight, then gray in their second year. The
leaves
A leaf (plural, : leaves) is any of the principal appendages of a vascular plant plant stem, stem, usually borne laterally aboveground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", wh ...
are long, with a serrated margin and a
petiole.
The
flower
A flower, sometimes known as a bloom or blossom, is the reproductive structure found in flowering plants (plants of the division Angiospermae). The biological function of a flower is to facilitate reproduction, usually by providing a mechani ...
s are white to pale pink, diameter with five petals, produced singly or in pairs and appearing before the leaves in early spring.
Almond grows best in Mediterranean climates with warm, dry summers and mild, wet winters. The optimal temperature for their growth is between and the tree buds have a
chilling requirement
The chilling requirement of a fruit is the minimum period of cold weather after which a fruit-bearing tree will blossom. It is often expressed in chill hours, which can be calculated in different ways, all of which essentially involve adding up ...
of 200 to 700 hours below to break dormancy.
Almonds begin bearing an economic crop in the third year after planting. Trees reach full bearing five to six years after planting. The fruit matures in the autumn, 7–8 months after flowering.
[
The almond fruit is long. It is not a ]nut
Nut often refers to:
* Nut (fruit), fruit composed of a hard shell and a seed, or a collective noun for dry and edible fruits or seeds
* Nut (hardware), fastener used with a bolt
Nut or Nuts may also refer to:
Arts, entertainment, and media Co ...
but a drupe
In botany, a drupe (or stone fruit) is an indehiscent fruit in which an outer fleshy part (exocarp, or skin, and mesocarp, or flesh) surrounds a single shell (the ''pit'', ''stone'', or '' pyrena'') of hardened endocarp with a seed (''kernel'') ...
. The outer covering, consisting of an outer exocarp
Fruit anatomy is the plant anatomy of the internal structure of fruit. Fruits are the mature ovary or ovaries of one or more flowers. They are found in three main anatomical categories: aggregate fruits, multiple fruits, and simple fruits. Aggr ...
, or skin, and mesocarp
Fruit anatomy is the plant anatomy of the internal structure of fruit. Fruits are the mature ovary or ovaries of one or more flowers. They are found in three main anatomical categories: aggregate fruits, multiple fruits, and simple fruits. Aggre ...
, or flesh, fleshy in other members of ''Prunus'' such as the plum
A plum is a fruit of some species in ''Prunus'' subg. ''Prunus'.'' Dried plums are called prunes.
History
Plums may have been one of the first fruits domesticated by humans. Three of the most abundantly cultivated species are not found i ...
and cherry
A cherry is the fruit of many plants of the genus ''Prunus'', and is a fleshy drupe (stone fruit).
Commercial cherries are obtained from cultivars of several species, such as the sweet ''Prunus avium'' and the sour ''Prunus cerasus''. The nam ...
, is instead a thick, leathery, gray-green coat (with a downy exterior), called the hull. Inside the hull is a woody endocarp
Fruit anatomy is the plant anatomy of the internal structure of fruit. Fruits are the mature ovary or ovaries of one or more flowers. They are found in three main anatomical categories: aggregate fruits, multiple fruits, and simple fruits. Agg ...
which forms a reticulated, hard shell (like the outside of a peach pit) called the pyrena
A pyrena or pyrene (commonly called a "pit" or "stone") is the fruitstone within a drupe or drupelet produced by the ossification of the endocarp or lining of the fruit. It consists of a hard endocarp tissue surrounding one or more seeds (also ...
. Inside the shell is the edible seed, commonly called a nut. Generally, one seed is present, but occasionally two occur. After the fruit matures, the hull splits and separates from the shell, and an abscission layer
Abscission () is the shedding of various parts of an organism, such as a plant dropping a leaf, fruit, flower, or seed. In zoology, abscission is the intentional shedding of a body part, such as the shedding of a claw, husk, or the autotomy of a ...
forms between the stem and the fruit so that the fruit can fall from the tree.
Taxonomy
Sweet and bitter almonds
The seeds of ''Prunus dulcis'' var. ''dulcis'' are predominantly sweet but some individual trees produce seeds that are somewhat more bitter. The genetic basis for bitterness involves a single gene, the bitter flavor furthermore being recessive
In genetics, dominance is the phenomenon of one variant (allele) of a gene on a chromosome masking or overriding the effect of a different variant of the same gene on the other copy of the chromosome. The first variant is termed dominant and t ...
, both aspects making this trait easier to domesticate. The fruits from ''Prunus dulcis'' var. ''amara'' are always bitter, as are the kernels from other species of genus ''Prunus'', such as apricot, peach and cherry (although to a lesser extent).
The bitter almond is slightly broader and shorter than the sweet almond and contains about 50% of the fixed oil that occurs in sweet almonds. It also contains the enzyme emulsin
β-Glucosidase (EC 3.2.1.21; systematic name β-D-glucoside glucohydrolase) is an enzyme that catalyses the following reaction:
: Hydrolysis of terminal, non-reducing β-D-glucosyl residues with release of β-D-glucose
Structure
β-Glucosidase ...
which, in the presence of water, acts on the two soluble
In chemistry, solubility is the ability of a substance, the solute, to form a solution with another substance, the solvent. Insolubility is the opposite property, the inability of the solute to form such a solution.
The extent of the solubil ...
glucoside
A glucoside is a glycoside that is derived from glucose. Glucosides are common in plants, but rare in animals. Glucose is produced when a glucoside is hydrolysed by purely chemical means, or decomposed by fermentation or enzymes.
The name was o ...
s amygdalin
Amygdalin (from Ancient Greek: ' "almond") is a naturally occurring chemical compound found in many plants, most notably in the seeds (kernels) of apricots, bitter almonds, apples, peaches, cherries, and plums.
Amygdalin is classified as a cy ...
and prunasin
(''R'')-prunasin is a cyanogenic glycoside related to amygdalin. Chemically, it is the glucoside of (''R'')-mandelonitrile.
Natural occurrences
Prunasin is found in species in the genus ''Prunus'' such as ''Prunus japonica'' or '' P. maximowicz ...
yielding glucose
Glucose is a simple sugar with the molecular formula . Glucose is overall the most abundant monosaccharide, a subcategory of carbohydrates. Glucose is mainly made by plants and most algae during photosynthesis from water and carbon dioxide, using ...
, cyanide
Cyanide is a naturally occurring, rapidly acting, toxic chemical that can exist in many different forms.
In chemistry, a cyanide () is a chemical compound that contains a functional group. This group, known as the cyano group, consists of ...
and the essential oil
An essential oil is a concentrated hydrophobic liquid containing volatile (easily evaporated at normal temperatures) chemical compounds from plants. Essential oils are also known as volatile oils, ethereal oils, aetheroleum, or simply as the o ...
of bitter almonds, which is nearly pure benzaldehyde
Benzaldehyde (C6H5CHO) is an organic compound consisting of a benzene ring with a formyl substituent. It is the simplest aromatic aldehyde and one of the most industrially useful.
It is a colorless liquid with a characteristic almond-like odor. ...
, the chemical causing the bitter flavor. Bitter almonds may yield 4–9 milligrams of hydrogen cyanide
Hydrogen cyanide, sometimes called prussic acid, is a chemical compound with the formula HCN and structure . It is a colorless, extremely poisonous, and flammable liquid that boils slightly above room temperature, at . HCN is produced on an ...
per almond and contain 42 times higher amounts of cyanide than the trace levels found in sweet almonds. The origin of cyanide content in bitter almonds is via the enzymatic hydrolysis
In biochemistry, enzymatic hydrolysis is a process in which enzymes facilitate the cleavage of bonds in molecules with the addition of the elements of water (i.e. hydrolysis). It plays an important role in the digestion of food.
It may be used t ...
of amygdalin. P450
Cytochromes P450 (CYPs) are a superfamily of enzymes containing heme as a cofactor that functions as monooxygenases. In mammals, these proteins oxidize steroids, fatty acids, and xenobiotics, and are important for the clearance of various compo ...
monooxygenase
Monooxygenases are enzymes that incorporate one hydroxyl group (−OH) into substrates in many metabolic pathways. In this reaction, the two atoms of dioxygen are reduced to one hydroxyl group and one H2O molecule by the concomitant oxidation o ...
s are involved in the amygdalin biosynthetic pathway. A point mutation in a bHLH transcription factor
In molecular biology, a transcription factor (TF) (or sequence-specific DNA-binding factor) is a protein that controls the rate of transcription of genetic information from DNA to messenger RNA, by binding to a specific DNA sequence. The fu ...
prevents transcription
Transcription refers to the process of converting sounds (voice, music etc.) into letters or musical notes, or producing a copy of something in another medium, including:
Genetics
* Transcription (biology), the copying of DNA into RNA, the fir ...
of the two cytochrome P450 genes, resulting in the sweet kernel trait.
Etymology
The word "almond" comes from Old French
Old French (, , ; Modern French: ) was the language spoken in most of the northern half of France from approximately the 8th to the 14th centuries. Rather than a unified language, Old French was a linkage of Romance dialects, mutually intelligib ...
''almande'' or ''alemande'', Late Latin
Late Latin ( la, Latinitas serior) is the scholarly name for the form of Literary Latin of late antiquity.Roberts (1996), p. 537. English dictionary definitions of Late Latin date this period from the , and continuing into the 7th century in t ...
*''amandula'', *''amindula'', derived from ''amygdala'' from the Ancient Greek
Ancient Greek includes the forms of the Greek language used in ancient Greece and the ancient world from around 1500 BC to 300 BC. It is often roughly divided into the following periods: Mycenaean Greek (), Dark Ages (), the Archaic peri ...
ἀμυγδάλη (''amygdálē'') (cf. amygdala
The amygdala (; plural: amygdalae or amygdalas; also '; Latin from Greek, , ', 'almond', 'tonsil') is one of two almond-shaped clusters of nuclei located deep and medially within the temporal lobes of the brain's cerebrum in complex verteb ...
, an almond-shaped portion of the brain). The ''al-'' in English, for the ''a-'' used in other languages may be due a confusion with the Arabic
Arabic (, ' ; , ' or ) is a Semitic languages, Semitic language spoken primarily across the Arab world.Semitic languages: an international handbook / edited by Stefan Weninger; in collaboration with Geoffrey Khan, Michael P. Streck, Janet C ...
article ''al'', the word having first dropped the ''a-'' as in the Italian form ''mandorla''; the British
British may refer to:
Peoples, culture, and language
* British people, nationals or natives of the United Kingdom, British Overseas Territories, and Crown Dependencies.
** Britishness, the British identity and common culture
* British English, ...
pronunciation ''ah-mond'' and the modern Catalan
Catalan may refer to:
Catalonia
From, or related to Catalonia:
* Catalan language, a Romance language
* Catalans, an ethnic group formed by the people from, or with origins in, Northern or southern Catalonia
Places
* 13178 Catalan, asteroid #1 ...
''ametlla'' and modern French ''amande'' show a form of the word closer to the original.
The adjective "amygdaloid" (literally "like an almond") is used to describe objects which are roughly almond-shaped, particularly a shape which is part way between a triangle
A triangle is a polygon with three Edge (geometry), edges and three Vertex (geometry), vertices. It is one of the basic shapes in geometry. A triangle with vertices ''A'', ''B'', and ''C'' is denoted \triangle ABC.
In Euclidean geometry, an ...
and an ellipse
In mathematics, an ellipse is a plane curve surrounding two focus (geometry), focal points, such that for all points on the curve, the sum of the two distances to the focal points is a constant. It generalizes a circle, which is the special ty ...
. For example, the amygdala
The amygdala (; plural: amygdalae or amygdalas; also '; Latin from Greek, , ', 'almond', 'tonsil') is one of two almond-shaped clusters of nuclei located deep and medially within the temporal lobes of the brain's cerebrum in complex verteb ...
of the brain, which uses a direct borrowing of the Greek term ''amygdalē''.
Distribution and habitat
Almond is native to Southwestern Asia and ancient remains of almonds were discovered in the Levant
The Levant () is an approximate historical geographical term referring to a large area in the Eastern Mediterranean region of Western Asia. In its narrowest sense, which is in use today in archaeology and other cultural contexts, it is eq ...
area. It was spread by humans in ancient times along the shores of the Mediterranean into northern Africa and southern Europe, and more recently transported to other parts of the world, notably California, United States.[Introduction to Fruit Crops (Published Online)]
Mark Rieger, 2006 The wild form of domesticated almond grows in parts of the Levant.
Selection of the sweet type from the many bitter types in the wild marked the beginning of almond domestication. It is unclear as to which wild ancestor of the almond created the domesticated species. The species ''Prunus fenzliana
''Prunus fenzliana'' is a species of wild almond native to the Caucasus areas of Turkey, Armenia, Azerbaijan, Iran, and Turkmenistan, preferring to grow at 1400-3500m above sea level. On the basis of morphology it has been long thought to be one ...
'' may be the most likely wild ancestor of the almond, in part because it is native to Armenia
Armenia (), , group=pron officially the Republic of Armenia,, is a landlocked country in the Armenian Highlands of Western Asia.The UNbr>classification of world regions places Armenia in Western Asia; the CIA World Factbook , , and ''Ox ...
and western Azerbaijan
Western Azerbaijan ( az, Qərbi Azərbaycan) is an Irredentism, irredentist political concept that is used in the Republic of Azerbaijan mostly to refer to the territory of the Republic of Armenia. Azerbaijani statements claim that the territory ...
, where it was apparently domesticated. Wild almond species were grown by early farmers, "at first unintentionally in the garbage heaps, and later intentionally in their orchards".
Cultivation
Almonds were one of the earliest domesticated fruit trees
A fruit tree is a tree which bears fruit that is consumed or used by animals and humans — all trees that are flowering plants produce fruit, which are the ripened ovaries of flowers containing one or more seeds. In horticultural usage, t ...
, due to "the ability of the grower to raise attractive almonds from seed. Thus, in spite of the fact that this plant does not lend itself to propagation from suckers or from cuttings, it could have been domesticated even before the introduction of grafting
Grafting or graftage is a horticultural technique whereby tissues of plants are joined so as to continue their growth together. The upper part of the combined plant is called the scion () while the lower part is called the rootstock. The succ ...
".[ Domesticated almonds appear in the ]Early Bronze Age
The Bronze Age is a historic period, lasting approximately from 3300 BC to 1200 BC, characterized by the use of bronze, the presence of writing in some areas, and other early features of urban civilization. The Bronze Age is the second prin ...
(3000–2000 BC), such as the archaeological sites of Numeira
Numeira (also an-Numayra) is an archaeological site in Jordan near the southern Dead Sea. The site has substantial Early Bronze Age remains.
The site is 280 m below sea level, on the shore of the Dead Sea.
Numeira is also the name given to ...
(Jordan),[ or possibly earlier. Another well-known archaeological example of the almond is the fruit found in ]Tutankhamun
Tutankhamun (, egy, twt-ꜥnḫ-jmn), Egyptological pronunciation Tutankhamen () (), sometimes referred to as King Tut, was an Egyptian pharaoh who was the last of his royal family to rule during the end of the Eighteenth Dynasty (ruled ...
's tomb in Egypt (c. 1325 BC), probably imported from the Levant.[ An article on almond tree cultivation in Spain is brought down in ]Ibn al-'Awwam
Ibn al-'Awwam ( ar, ابن العوام), also called Abu Zakariya Ibn al-Awwam ( ar, أبو زكريا بن العوام), was a Muslim Arab agriculturist who flourished at Seville (modern-day southern Spain) in the later 12th century. He wrote a ...
's 12th-century agricultural work, ''Book on Agriculture''.
Of the European countries that the Royal Botanic Garden Edinburgh
The Royal Botanic Garden Edinburgh (RBGE) is a scientific centre for the study of plants, their diversity and conservation, as well as a popular tourist attraction. Founded in 1670 as a physic garden to grow medicinal plants, today it occupies ...
reported as cultivating almonds, Germany is the northernmost, though the domesticated form can be found as far north as Iceland.
Varieties
Almond trees are small to medium sized but commercial cultivars can be grafted
Grafting or graftage is a horticultural technique whereby tissues of plants are joined so as to continue their growth together. The upper part of the combined plant is called the scion () while the lower part is called the rootstock. The succ ...
onto a different root-stock to produce smaller trees. Varieties include:
* Nonpareil – originates in the 1800s. A large tree that produces large, smooth, thin-shelled almonds with 60–65% edible kernel per nut. Requires pollination from other almond varieties for good nut production.[
* Tuono – originates in Italy. Has thicker, hairier shells with only 32% of edible kernel per nut. The thicker shell gives some protection from pests such as the navel orangeworm. Does not require pollination by other almond varieties.][
* Mariana – used as a rootstock to result in smaller trees
]
Breeding
Breeding program
A breeding program is the planned breeding of a group of animals or plants, usually involving at least several individuals and extending over several generations. There are a couple of breeding methods, such as artificial (which is man made) and ...
s have found the high shell-seal trait.
Pollination
The most widely planted varieties of almond are self-incompatible
Self-incompatibility (SI) is a general name for several genetic mechanisms that prevent self-fertilization in sexually reproducing organisms, and thus encourage outcrossing and allogamy. It is contrasted with separation of sexes among individuals ...
; hence these trees require pollen from a tree with different genetic characters to produce seeds. Almond orchards therefore must grow mixtures of almond varieties. In addition, the pollen is transferred from flower to flower by insects; therefore commercial growers must ensure there are enough insects to perform this task. The large scale of almond production in the U.S. creates a significant problem of providing enough pollinating insects. Additional pollinating insects are therefore brought to the trees. The pollination
Pollination is the transfer of pollen from an anther of a plant to the stigma of a plant, later enabling fertilisation and the production of seeds, most often by an animal or by wind. Pollinating agents can be animals such as insects, birds ...
of California's almonds is the largest annual managed pollination event in the world, with 1.4 million hives (nearly half of all beehives
A beehive is an enclosed structure in which some honey bee species of the subgenus '' Apis'' live and raise their young. Though the word ''beehive'' is commonly used to describe the nest of any bee colony, scientific and professional literature ...
in the US) being brought to the almond orchards each February.[
Much of the supply of bees is managed by pollination brokers, who contract with migratory ]beekeeper
A beekeeper is a person who keeps honey bees.
Beekeepers are also called honey farmers, apiarists, or less commonly, apiculturists (both from the Latin '' apis'', bee; cf. apiary). The term beekeeper refers to a person who keeps honey bees i ...
s from at least 49 states for the event. This business was heavily affected by colony collapse disorder
Colony collapse disorder (CCD) is an abnormal phenomenon that occurs when the majority of worker bees in a honey bee colony disappear, leaving behind a queen, plenty of food, and a few nurse bees to care for the remaining immature bees. While s ...
at the turn of the 21st century, causing a nationwide shortage of honey bees and increasing the price of insect pollination
Entomophily or insect pollination is a form of pollination whereby pollen of plants, especially but not only of flowering plants, is distributed by insects. Flowers pollinated by insects typically advertise themselves with bright colours, some ...
. To partially protect almond growers from these costs, researchers at the USA government Agricultural Research Service
The Agricultural Research Service (ARS) is the principal in-house research agency of the United States Department of Agriculture (USDA). ARS is one of four agencies in USDA's Research, Education and Economics mission area. ARS is charged with ext ...
have developed self-pollinating
Self-pollination is a form of pollination in which pollen from the same plant arrives at the stigma of a flower (in flowering plants) or at the ovule (in gymnosperms). There are two types of self-pollination: in autogamy, pollen is transferred to ...
almond trees that combine this character with quality characters such as a flavor and yield. Self-pollinating almond varieties exist, but they lack some commercial characters. However, through natural hybridisation between different almond varieties, a new variety that was self-pollinating with a high yield of commercial quality nuts was produced.
Diseases
Almond trees can be attacked by an array of damaging microbes, fungal pathogens, plant viruses, and bacteria.
Pests
Pavement ants (''Tetramorium caespitum
''Tetramorium caespitum'', also known as the pavement ant, is a species of ant in the family Formicidae.
References
Tetramorium
Ants described in 1758
Taxa named by Carl Linnaeus
{{ant-stub ...
''), southern fire ants (''Solenopsis xyloni
The southern fire ant (''Solenopsis xyloni''), also known as the Californian fire ant or cotton ant, is a stinging fire ant native to southern parts of the United States. Its behaviour is similar to the red imported fire ant ''(S. invicta)'', alt ...
''), and thief ants (''Solenopsis molesta
''Solenopsis molesta'' is the best known species of '' Solenopsis'' thief ants. They get their names from their habit of nesting close to other ant nests, from which they steal food. They are also called grease ants because they are attracted to ...
'') are seed predator
Seed predation, often referred to as granivory, is a type of plant-animal interaction in which granivores (seed predators) feed on the seeds of plants as a main or exclusive food source,Hulme, P.E. and Benkman, C.W. (2002) "Granivory", pp. 13 ...
s. '' Bryobia rubrioculus'' mites are most known for their damage to this crop.
Sustainability
Almond production in California is concentrated mainly in the Central Valley, where the mild climate, rich soil, abundant sunshine and water supply make for ideal growing conditions. Due to the persistent droughts in California in the early 21st century, it became more difficult to raise almonds in a sustainable manner. The issue is complex because of the high amount of water needed to produce almonds: a single almond requires roughly of water to grow properly.[ Regulations related to water supplies are changing so some growers have destroyed their current almond orchards to replace with either younger trees or a different crop such as ]pistachio
The pistachio (, ''Pistacia vera''), a member of the cashew family, is a small tree originating from Central Asia and the Middle East. The tree produces seeds that are widely consumed as food.
''Pistacia vera'' is often confused with other sp ...
that needs less water.
Sustainability strategies implemented by the Almond Board of California
California produces 80% of the world's almonds and 100% of the United States commercial supply. Although almonds are not native to California, a hot, dry Mediterranean climate and developed water infrastructure create favorable conditions for co ...
and almond farmers include:
* tree and soil health
Soil health is a state of a soil meeting its range of ecosystem functions as appropriate to its environment. In more colloquial terms, the health of soil arises from favorable interactions of all soil components (living and non-living) that belong ...
, and other farming practices
* minimizing dust production during the harvest
* bee health
* irrigation
Irrigation (also referred to as watering) is the practice of applying controlled amounts of water to land to help grow Crop, crops, Landscape plant, landscape plants, and Lawn, lawns. Irrigation has been a key aspect of agriculture for over 5,00 ...
guidelines for farmers
* food safety
* use of waste biomass
Biomass is plant-based material used as a fuel for heat or electricity production. It can be in the form of wood, wood residues, energy crops, agricultural residues, and waste from industry, farms, and households. Some people use the terms bi ...
as coproducts with a goal to achieve zero waste
Zero waste is a set of principles focused on waste prevention that encourages redesigning resource life cycles so that all products are reused. The goal of this movement is to avoid sending trash to landfills, incinerators, or the ocean. Curren ...
* use of solar energy
Solar energy is radiant light and heat from the Sun that is harnessed using a range of technologies such as solar power to generate electricity, solar thermal energy (including solar water heating), and solar architecture. It is an essenti ...
during processing
* job development
* support of scientific research
The scientific method is an empirical method for acquiring knowledge that has characterized the development of science since at least the 17th century (with notable practitioners in previous centuries; see the article history of scientific m ...
to investigate potential health benefits of consuming almonds
* international education about sustainability practices
Production
In 2020, world production of almonds was 4.1 million tonnes
The tonne ( or ; symbol: t) is a unit of mass equal to 1000 kilograms. It is a non-SI unit accepted for use with SI. It is also referred to as a metric ton to distinguish it from the non-metric units of the short ton ( United States ...
, led by the United States providing 57% of the world total (table). Other leading producers were Spain, Australia, and Iran
Iran, officially the Islamic Republic of Iran, and also called Persia, is a country located in Western Asia. It is bordered by Iraq and Turkey to the west, by Azerbaijan and Armenia to the northwest, by the Caspian Sea and Turkmeni ...
.
United States
In the United States, production is concentrated in California where and six different almond varieties were under cultivation in 2017, with a yield of of shelled almonds. California production is marked by a period of intense pollination during late winter by rented
Renting, also known as hiring or letting, is an agreement where a payment is made for the temporary use of a good, service or property owned by another. A gross lease is when the tenant pays a flat rental amount and the landlord pays for a ...
commercial bees transported by truck across the U.S. to almond groves, requiring more than half of the total U.S. commercial honeybee population. The value of total U.S. exports of shelled almonds in 2016 was $3.2 billion.
All commercially grown almonds sold as food in the U.S. are sweet cultivars. The U.S. Food and Drug Administration
The United States Food and Drug Administration (FDA or US FDA) is a List of United States federal agencies, federal agency of the United States Department of Health and Human Services, Department of Health and Human Services. The FDA is respon ...
reported in 2010 that some fractions of imported sweet almonds were contaminated with bitter almonds, which contain cyanide.
Spain
Spain has diverse commercial cultivars of almonds grown in Catalonia
Catalonia (; ca, Catalunya ; Aranese Occitan: ''Catalonha'' ; es, Cataluña ) is an autonomous community of Spain, designated as a ''nationality'' by its Statute of Autonomy.
Most of the territory (except the Val d'Aran) lies on the north ...
, Valencia
Valencia ( va, València) is the capital of the Autonomous communities of Spain, autonomous community of Valencian Community, Valencia and the Municipalities of Spain, third-most populated municipality in Spain, with 791,413 inhabitants. It is ...
, Murcia
Murcia (, , ) is a city in south-eastern Spain, the capital and most populous city of the autonomous community of the Region of Murcia, and the seventh largest city in the country. It has a population of 460,349 inhabitants in 2021 (about one ...
, Andalusia, and Aragón
Aragon ( , ; Spanish and an, Aragón ; ca, Aragó ) is an autonomous community in Spain, coextensive with the medieval Kingdom of Aragon. In northeastern Spain, the Aragonese autonomous community comprises three provinces (from north to sout ...
regions, and the Balearic Islands
The Balearic Islands ( es, Islas Baleares ; or ca, Illes Balears ) are an archipelago in the Balearic Sea, near the eastern coast of the Iberian Peninsula. The archipelago is an autonomous community and a province of Spain; its capital is ...
. Production in 2016 declined 2% nationally compared to 2015 production data.[
The 'Marcona' almond cultivar is recognizably different from other almonds and is marketed by name.] The kernel is short, round, relatively sweet, and delicate in texture. Its origin is unknown and has been grown in Spain for a long time; the tree is very productive, and the shell of the nut is very hard.[
]
Australia
Australia is the largest almond production region in the Southern Hemisphere. Most of the almond orchards are located along the Murray River
The Murray River (in South Australia: River Murray) (Ngarrindjeri: ''Millewa'', Yorta Yorta: ''Tongala'') is a river in Southeastern Australia. It is Australia's longest river at extent. Its tributaries include five of the next six longest r ...
corridor in New South Wales
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, image_map = New South Wales in Australia.svg
, map_caption = Location of New South Wales in AustraliaCoordinates:
, subdivision_type = Country
, subdivision_name = Australia
, established_title = Before federation
, es ...
, Victoria, and South Australia
South Australia (commonly abbreviated as SA) is a state in the southern central part of Australia. It covers some of the most arid parts of the country. With a total land area of , it is the fourth-largest of Australia's states and territories ...
.
Toxicity
Bitter almonds contain 42 times higher amounts of cyanide than the trace levels found in sweet almonds. Extract of bitter almond was once used medicinally but even in small doses, effects are severe or lethal, especially in children; the cyanide must be removed before consumption. The acute oral lethal dose of cyanide for adult humans is reported to be of body weight (approximately 50 bitter almonds), so that for children consuming 5–10 bitter almonds may be fatal. Symptoms of eating such almonds include vertigo and other typical cyanide poisoning effects.
Almonds may cause food allergy, allergy or food intolerance, intolerance. Cross-reactivity is common with peach
The peach (''Prunus persica'') is a deciduous tree first domesticated and cultivated in Zhejiang province of Eastern China. It bears edible juicy fruits with various characteristics, most called peaches and others (the glossy-skinned, non-fu ...
allergens (lipid transfer proteins) and Tree nut allergy, tree nut allergens. Symptoms range from local signs and symptoms (e.g., oral allergy syndrome, contact urticaria) to systemic signs and symptoms including anaphylaxis (e.g., urticaria, angioedema, gastrointestinal and respiratory symptoms).
Almonds are susceptible to aflatoxin-producing molds. Aflatoxins are potent carcinogenic chemicals produced by molds such as ''Aspergillus flavus'' and ''Aspergillus parasiticus''. The mold contamination may occur from soil, previously infested almonds, and almond pests such as navel-orange worm. High levels of mold growth typically appear as gray to black filament like growth. It is unsafe to eat mold-infected tree nuts.
Some countries have strict limits on allowable levels of aflatoxin contamination of almonds and require adequate testing before the nuts can be marketed to their citizens. The European Union, for example, introduced a requirement since 2007 that all almond shipments to EU be tested for aflatoxin. If aflatoxin does not meet the strict safety regulations, the entire consignment may be reprocessed to eliminate the aflatoxin or it must be destroyed.
Breeding programs have found the trait. High shell-seal provides crop disease resistance, resistance against these ''Aspergillus'' species and so against the development of their toxins.
Mandatory pasteurization in California
After tracing cases of salmonellosis to almonds, the USDA approved a proposal by the Almond Board of California to pasteurize almonds sold to the public. After publishing the rule in March 2007, the almond pasteurization program became mandatory for California companies effective 1 September 2007. Raw, untreated California almonds have not been available in the U.S. since then.
California almonds labeled "raw" must be steam-pasteurized or chemically treated with propylene oxide (PPO). This does not apply to imported almonds or almonds sold from the grower directly to the consumer in small quantities. The treatment also is not required for raw almonds sold for export outside of North America.
The Almond Board of California states: "PPO residue dissipates after treatment". The U.S. Environmental Protection Agency has reported: "Propylene oxide has been detected in fumigated food products; consumption of contaminated food is another possible route of exposure". PPO is classified as List of IARC Group 2B carcinogens, Group 2B ("possibly carcinogenic to humans").
The USDA-approved marketing order was challenged in court by organic farmers organized by the Cornucopia Institute, a Wisconsin-based farm policy research group which filed a lawsuit in September 2008. According to the institute, this almond marketing order has imposed significant financial burdens on small-scale and organic growers and damaged domestic almond markets. A federal judge dismissed the lawsuit in early 2009 on procedural grounds. In August 2010, a federal appeals court ruled that the farmers have a right to appeal the USDA regulation. In March 2013, the court vacated the suit on the basis that the objections should have been raised in 2007 when the regulation was first proposed.
Uses
Nutrition
Almonds are 4% water, 22% carbohydrates, 21% protein, and 50% fat (table). In a reference amount, almonds supply of food energy. The almond is a nutritionally dense food (table), providing a rich source (20% or more of the Daily Value, DV) of the B vitamins riboflavin and Niacin (nutrient), niacin, vitamin E, and the essential minerals calcium, copper, iron, magnesium, manganese, phosphorus, and zinc. Almonds are a moderate source (10–19% DV) of the B vitamins thiamine, vitamin B6, vitamin B6, and folate, choline, and the essential mineral potassium. They also contain substantial dietary fiber, the monounsaturated fat, oleic acid, and the polyunsaturated fat, linoleic acid. Typical of nuts and seeds, almonds are a source of phytosterols such as beta-sitosterol, stigmasterol, campesterol, sitostanol, and campestanol.
Health
Almonds are included as a good source of protein among recommended healthy foods by the U.S. Department of Agriculture (USDA). A 2016 review of clinical research indicated that regular consumption of almonds may reduce the risk of heart disease by lowering blood levels of LDL cholesterol.
Culinary
While the almond is often eaten on its own, raw or toasted, it is also a component of various dishes. Almonds are available in many forms, such as whole, slivered, and ground into flour. Almond pieces around in size, called "nibs", are used for special purposes such as decoration.
Almonds are a common addition to breakfast muesli or oatmeal.
Desserts
A wide range of classic sweets feature almonds as a central ingredient. Marzipan was developed in the Middle Ages. Since the 19th century almonds have been used to make bread, almond butter, cakes and puddings, candied confections, almond cream-filled pastries, nougat, cookies (macaroons, biscotti and qurabiya), and cakes (Financier (pastry), financiers, Esterházy torte), and other sweets and desserts.
The young, developing fruit of the almond tree can be eaten whole (green almonds) when they are still green and fleshy on the outside and the inner shell has not yet hardened. The fruit is somewhat sour, but is a popular snack in parts of the Middle East, eaten dipped in salt to balance the sour taste. Also in the Middle East they are often eaten with dates. They are available only from mid-April to mid-June in the Northern Hemisphere; pickling or brining extends the fruit's shelf life.
=Marzipan
=
Marzipan, a smooth, sweetened almond paste, is used in a number of elegant cakes and desserts. Princess cake is covered by marzipan (similar to Fondant icing, fondant), as is Battenberg cake. In Sicily, sponge cake is covered with marzipan
Marzipan is a confectionery, confection consisting primarily of sugar, honey, and almond meal (ground almonds), sometimes augmented with almond oil or extract.
It is often made into Confectionery, sweets; common uses are chocolate-covered marzi ...
to make cassatella di sant'Agata and cassata siciliana, and marzipan is dyed and crafted into realistic fruit shaped to make frutta martorana. The Andalusian cuisine, Andalusian Christmas pastry ''pan de Cádiz'' is filled with marzipan and candied fruit.
World cuisines
*In French cuisine, alternating layers of almond and hazelnut meringue are used to make the dessert ''dacquoise''. Pithivier is one of many almond cream-filled pastries.
*In German cuisine, Germany, List of Easter breads, Easter bread called ''Deutsches Osterbrot'' is baked with raisins and almonds.
*In Greece almond flour is used to make ''amygdalopita'', a ''glyka tapsiou'' dessert cake baking in a tray. Almonds are used for ''kourabiedes'', a Greek version of the traditional ''quarabiya'' almond biscuits. A soft drink known as ''soumada'' is made from almonds in various regions.
*In Saudi Arabia, almonds are a typical embellishment for the rice dish kabsa.
*In Iran, green almonds are dipped in sea salt and eaten as snacks on street markets; they are called ''chaqale bâdam''. Candied almonds called noghl are served alongside tea and coffee. Also, sweet almonds are used to prepare special food for babies, named ''harire badam''. Almonds are added to some foods, cookies, and desserts, or are used to decorate foods. People in Iran consume roasted nuts for special events, for example, during New Year (Nowruz) parties.
*In Italy, ''colomba di Pasqua'' is a traditional Easter cake made with almonds. Bitter almonds are the base for ''Amaretti di Saronno, amaretti'' cookies, a common dessert. Almonds are also a common choice as the nuts to include in ''torrone''.
*In Morocco, almonds in the form of sweet almond paste are the main ingredient in pastry fillings, and several other List of Moroccan dishes#Desserts, desserts. Fried blanched whole almonds are also used to decorate sweet ''tajines'' such as lamb with prunes. Southwestern Berber regions of Essaouira and Souss are also known for ''amlou'', a spread made of almond paste, argan oil, and honey. Almond paste is also mixed with toasted flour and among others, honey, olive oil or butter, anise, fennel, sesame seeds, and cinnamon to make ''sellou'' (also called ''zamita'' in Meknes or ''slilou'' in Marrakech), a sweet snack known for its long shelf life and high nutritive value.
*In Indian cuisine, almonds are the base ingredients of ''pasanda''-style and Mughlai curry, curries. ''Badam halva'' is a sweet made from almonds with added coloring. Almond flakes are added to many sweets (such as ''sohan barfi''), and are usually visible sticking to the outer surface. Almonds form the base of various drinks which are supposed to have cooling properties. Almond sherbet or ''sherbet-e-badaam'', is a popular summer drink. Almonds are also sold as a snack with added salt.
*In Israel almonds are used as a topping for tahini cookies or eaten as a snack.
*In Spain ''Marcona'' almonds are usually toasted in oil and lightly salted. They are used by Spanish confectioners to prepare a sweet called ''turrón''.
*In Arabian cuisine, almonds are commonly used as garnishing for Mansaf.
Certain natural food stores sell "bitter almonds" or "apricot kernels" labeled as such, requiring significant caution by consumers for how to prepare and eat these products.
Milk
Almonds can be processed into a milk substitute called almond milk; the nut's soft texture, mild flavor, and light coloring (when skinned) make for an efficient analog to dairy, and a soy-free choice for lactose intolerant people and vegans. Raw, blanched, and lightly toasted almonds work well for different production techniques, some of which are similar to that of soymilk and some of which use no heat, resulting in raw milk.
Almond milk, along with almond butter and almond oil, are a versatile products used in both sweet and savoury dishes.
In Moroccan cuisine, sharbat billooz is one of the best known beverages, served for weddings, it is made by blending blanched almonds with milk, sugar and other flavorings.
Flour and skins
Almond flour or ground almond meal combined with sugar or honey as marzipan
Marzipan is a confectionery, confection consisting primarily of sugar, honey, and almond meal (ground almonds), sometimes augmented with almond oil or extract.
It is often made into Confectionery, sweets; common uses are chocolate-covered marzi ...
is often used as a gluten-free alternative to wheat flour in cooking and baking.
Almonds contain polyphenols in their seed coat, skins consisting of flavonols, flavan-3-ols, hydroxybenzoic acids and flavanones analogous to those of certain fruits and vegetables. These phenolic compounds and almond skin prebiotic (nutrition), prebiotic dietary fiber have commercial interest as food additives or dietary supplements.[
]
Syrup
Historically, almond syrup was an emulsion of sweet and bitter almonds, usually made with barley syrup (orgeat syrup) or in a syrup of orange flower water and sugar, often flavored with a synthetic aroma of almonds. Orgeat syrup is an important ingredient in the Mai Tai and many other Tiki bar, Tiki drinks.
Due to the cyanide
Cyanide is a naturally occurring, rapidly acting, toxic chemical that can exist in many different forms.
In chemistry, a cyanide () is a chemical compound that contains a functional group. This group, known as the cyano group, consists of ...
found in bitter almonds, modern syrups generally are produced only from sweet almonds. Such syrup products do not contain significant levels of hydrocyanic acid, so are generally considered safe for human consumption.
Oils
Almonds are a rich source of oil, with 50% of kernel dry mass as fat (whole almond nutrition table). In relation to total dry mass of the kernel, almond oil contains 32% monounsaturated oleic acid (an omega-9 fatty acid), 13% linoleic acid (a polyunsaturated Omega-6 fatty acid, omega-6 essential fatty acid), and 10% saturated fatty acid (mainly as palmitic acid). Linolenic acid, a polyunsaturated omega-3 fat, is not present (table). Almond oil is a rich source of vitamin E, providing 261% of the Daily Value per 100 millilitres.
When almond oil is analyzed separately and expressed per 100 grams as a reference mass, the oil provides of food energy, 8 grams of saturated fat (81% of which is palmitic acid), 70 grams of oleic acid, and 17 grams of linoleic acid (oil table).
''Oleum amygdalae'', the fixed oil, is prepared from either sweet or bitter almonds, and is a glyceryl oleate with a slight odour and a nutty taste. It is almost insoluble in ethanol, alcohol but readily soluble in chloroform or diethyl ether, ether. Almond oil is obtained from the dried seed, kernel of almonds. Sweet almond oil is used as a carrier oil in aromatherapy and cosmetics while bitter almond oil, containing benzaldehyde, is used as a food flavouring and in perfume.
In culture
The almond is highly revered in some cultures. The tree originated in the Middle East. In the Bible the almond is mentioned ten times, beginning with Book of Genesis, Genesis 43:11, where it is described as "among the best of fruits". In Book of Numbers, Numbers 17 Levi is chosen from the other tribes of Israel by Aaron's rod, which brought forth almond flowers. The almond blossom supplied a model for the Menorah (Temple), menorah which stood in the Holy Temple, "Three cups, shaped like almond blossoms, were on one branch, with a knob and a flower; and three cups, shaped like almond blossoms, were on the other...on the candlestick itself were four cups, shaped like almond blossoms, with its knobs and flowers" (Book of Exodus, Exodus 25:33–34; 37:19–20). Many Sephardi Jews, Sephardic Jews give five almonds to each guest before special occasions like weddings.
Similarly, Christian symbolism often uses almond branches as a symbol of the virgin birth of Jesus; paintings and icons often include mandorla, almond-shaped haloes encircling the Christ Child and as a symbol of Mary, the mother of Jesus, Mary. The word "Luz", which appears in Genesis 30:37, sometimes translated as "hazel", may actually be derived from the Aramaic name for almond (Luz), and is translated as such in the New International Version and other versions of the Bible. The Arabic name for almond is لوز "lauz" or "lūz". In some parts of the Levant and North Africa it is pronounced "loz", which is very close to its Aramaic origin.
The Entrance of the flower (''La entrada de la flor'') is an event celebrated on 1 February in Torrent, Valencia, Torrent, Spain, in which the clavarios and members of the Confrerie of the Mother of God deliver a branch of the first-blooming almond-tree to the Virgin.
See also
* Fruit tree forms
* Fruit tree propagation
* Fruit tree pruning
* List of almond dishes
* List of edible seeds
References
External links
*
*
University of California Fruit and Nut Research and Information Center
{{Authority control
Almonds,
Prunus, Almond
Edible nuts and seeds
Flora of Asia
Pollination management
Snack foods
Nut oils, Almond oil
Crops
Fruit trees
Symbols of California
Flora of Lebanon and Syria