Cashew

Cashewis the common name of a tropicalevergreen treeAnacardium occidentale, in the familyAnacardiaceae. It is native toSouth Americaand is the source of the cashew nut and the cashew apple, anaccessory fruit. The tree can grow as tall as 14 meters (46 feet), but the dwarf cultivars, growing up to 6 m (20 ft), prove more profitable, with earlier maturity and greater yields. The cashewnutis edible and is eaten on its own as asnack, used in recipes, or processed into cashew cheese orcashew butter. The nut is often simply called a 'cashew'. The cashew apple is a light reddish to yellow fruit, whose pulp and juice can be processed into a sweet,astringentfruit drink or fermented and distilled into liquor.
In 2023, 3.9 milliontonnesof cashew nuts were harvested globally, led by theIvory CoastandIndia. In addition to the nut and fruit, the shell yields derivatives used in lubricants, waterproofing, and paints.
The cashew tree is large andevergreen, growing to 14 metres (46 feet) tall, with a short, often irregularly shaped trunk.Theleavesare spirally arranged, leathery textured, elliptic to obovate,4–22 centimetres (1+1⁄2–8+3⁄4inches) long and2–15 cm (3⁄4–6 in)  broad, with smooth margins. Theflowersare produced in apanicleorcorymbup to 26 cm (10 in) long; each flower is small, pale green at first, then turning reddish, with five slender, acutepetals7–15 millimeters (1⁄4–5⁄8in) long.The largest cashew tree in the worldcovers an area around 7,500 m(81,000 sq ft) and is located inNatal,Brazil.
The fruit of the cashew tree is anaccessory fruit(sometimes called a pseudocarp or false fruit).What appears to be the fruit is an oval or pear-shaped structure, ahypocarpium, that develops from thepediceland the receptacle of the cashew flower.Called the cashew apple, better known in Central America asmarañón, it ripens into a yellow or red structure about5–11 cm (2–4+1⁄4in) long.
The true fruit of the cashew tree is akidney-shaped orboxing glove-shapeddrupethat grows at the end of the cashew apple.The drupe first develops on the tree and then the pedicel expands to become the cashew apple.The drupe becomes the true fruit, a singleshell-encasedseed, which is often considered anutin the culinary sense.The seed is surrounded by a double-shell that contains an allergenicphenolicresin,anacardic acid- which is a potent skinirritantchemically related to the better-known and alsotoxicallergenic oilurushiol, which is found in the relatedpoison ivyandlacquer tree.
The English name derives from the Portuguese name for the fruit of the cashew tree:Caju(Portuguese pronunciation:[kaˈʒu]), also known asacaju, which itself is from theTupiwordacajú, literally meaning "nut that produces itself".
Thegeneric nameAnacardiumis composed of the Greek prefixana-(ἀνά-,aná, 'up, upward'), the Greekcardia(καρδία,kardía, 'heart'), and theNeo-Latinsuffix-ium. It possibly refers to the heart shape of the fruit,to "the top of the fruit stem"or to the seed.The wordanacardiumwas earlier used to refer toSemecarpus anacardium(the marking nut tree) beforeCarl Linnaeustransferred it to the cashew; both plants are in the same family.Theepithetoccidentalederives from the Western (or Occidental) world.
The plant has diversecommon namesin various languages among its wide distribution range,includinganacardier(French) with the fruit referred to aspomme de cajou,caju(Portuguese pronunciation:[kaˈʒu]), oracaju(Portuguese).
The species is native to tropical South Americaand later was distributed around the world in the 1500s byPortuguese explorers.Portuguese colonists in Brazil began exporting cashew nuts as early as the 1550s.The Portuguese took it toGoa, formerlyEstado da Índia Portuguesain India, between 1560 and 1565. From there, it spread throughout Southeast Asia and eventually Africa.
The cashew tree is cultivated in the tropics between 25°N and 25°S, and is well-adapted to hot lowland areas with a pronounced dry season, where the mango and tamarind trees also thrive.The traditional cashew tree is tall, up to 14 m (46 ft), requiring three years from planting before it starts production, and eight years before economic harvests.
More recent breeds, such as the dwarf cashew trees, are up to 6 m (20 ft) tall and start producing after the first year, with economic yields after three years. The cashew nut yields for the traditional tree are about 0.25 t (0.25 long tons; 0.28 short tons) per hectare, in contrast to over a ton per hectare for the dwarf variety. Grafting and other modern tree management technologies improve and sustain cashew nut yields in commercial orchards.
In 2023, global production of cashew nuts (as the kernel) was 3.9 milliontonnes, led by Ivory Coast and India with a combined 46% of the world total (table).
Almost all cashews produced in Africa between 2000 and 2019 were exported as raw nuts which are much less profitable than shelled nuts.One of the goals of theAfrican Cashew Allianceis to promote Africa's cashew processing capabilities to improve the profitability of Africa's cashew industry.
Some people areallergicto cashews, but they are a less frequentallergenthan other tree nuts orpeanuts.For up to 6% of children and 3% of adults, consuming cashews may causeallergic reactions, ranging from mild discomfort to life-threateninganaphylaxis.These allergies are triggered by the proteins found in tree nuts, and cooking often does not remove or change these proteins.Reactions to cashew and tree nuts can also occur as a consequence of hidden nut ingredients or traces of nuts that may inadvertently be introduced during food processing, handling, or manufacturing.
Theshellof the cashew nut contains oil compounds that can causecontact dermatitissimilar topoison ivy, primarily resulting from thephenolic lipids,anacardic acid, andcardanol.Because it can cause dermatitis, cashews are typically not sold in the shell to consumers.Readily and inexpensively extracted from the waste shells, cardanol is under research for its potential applications innanomaterialsandbiotechnology.
Raw cashew nuts are 5% water, 30%carbohydrates, 44%fat, and 18%protein(table). In a 100-gram reference amount, raw cashews provide 553kilocalories, 67% of theDaily Value(DV) in total fats, 36% DV ofprotein, 13% DV ofdietary fiber, and 11% DV ofcarbohydrates.Cashew nuts are rich sources (20% or more of the DV) ofdietary minerals, including particularlycopper,manganese,phosphorus, andmagnesium(79-110% DV), and ofthiamin,vitamin B6, andvitamin K(32-37% DV).Iron,potassium,zinc, andseleniumare present in significant content (14-61% DV) (table).Cashews (100g, raw) contain 113 milligrams (1.74 gr) ofbeta-sitosterol.
Culinary uses for cashew seeds in snacking and cooking are similar to those for all tree seeds called nuts.
Cashews are commonly used inSouth Asian cuisine, whole for garnishing sweets or curries, or ground into a pastethat forms a base of sauces for curries (e.g.,korma), or some sweets (e.g.,kaju barfi). It is also used in powdered form in the preparation of several Indian sweets and desserts. InGoan cuisine, both roasted and raw kernels ofGoa Kajuare used whole for making curries and sweets. Cashews are also used inThaiandChinese cuisines, generally in whole form. In the Philippines, cashew is a known product ofAntipoloand is eaten withsuman. The province ofPampangaalso has a sweet dessert calledturrones de casuy, which is cashewmarzipanwrapped in white wafers. In Indonesia, roasted and salted cashews are calledkacang meteorkacang mede, while the cashew apple is calledjambu monyet(lit.'monkey rose apple').
In the 21st century, cashew cultivation increased in several African countries to meet the manufacturing demands forcashew milk, aplant milkalternative todairy milk.In Mozambique,bolo polanais a cake prepared using powdered cashews and mashed potatoes as the main ingredients. This dessert is common in South Africa.
The cashew nut kernel has a slight curvature and twocotyledons, each representing around 20-25% of the weight of the nut. It is encased in a reddish-brown membrane called a husk, which accounts for approximately 5% of the total nut. Cashew nut husk is used in emerging industrial applications, such as anadsorbent,composites,biopolymers,dyes, and enzyme synthesis.
The mature cashew apple can be eaten fresh, cooked in curries, or fermented into vinegar, citric acid,or an alcoholic drink.It is also used to make preserves, chutneys, and jams in some countries, such as India and Brazil.In many countries, particularly in South America, the cashew apple is used to flavor drinks, both alcoholic and nonalcoholic.
In Brazil, cashew fruit juice and fruit pulp are used to make sweets, and juice mixed with alcoholic beverages such ascachaça, and as flour, milk, or cheese.In Panama, the cashew fruit is cooked with water and sugar for a prolonged time to make a sweet, brown, paste-like dessert calleddulce de marañón(marañónbeing a Spanish name for cashew).
Cashew nuts are more widely traded than cashew apples, because the fruit, unlike the nut, is easily bruised and has a very limited shelf life.Cashew apple juice, however, may be used for manufacturing blended juices.
When the apple is consumed, itsastringencyis sometimes removed by steaming the fruit for five minutes before washing it in cold water.Steepingthe fruit in boiling salt water for five minutes reduces the astringency.
In Cambodia, where the plant is usually grown as an ornamental rather than an economic tree, the fruit is a delicacy and is eaten with salt.
In the Indian state ofGoa, the ripened cashew apples are mashed, and the juice, called "neero", is extracted and kept for fermentationfor a few days. This fermented juice then undergoes a double distillation process. The resulting beverage is calledfenior fenny.Feniis about 40-42% alcohol (80-84 proof). The single-distilled version is calledurrak, which is about 15% alcohol (30 proof).In Tanzania, the cashew apple (biboinSwahili) is dried and reconstituted with water and fermented, then distilled to make a strong liquor calledgongo.
Cashew nut oil is a dark yellow oil derived from pressing the cashew nuts (typically from lower-value broken chunks created accidentally during processing) and used for cooking or salad dressing. The highest quality oil is produced from a single cold pressing.
Cashew nutshell liquid (CNSL) or cashew shell oil (CAS registry number8007-24-7) is a naturalresinwith a yellowishsheenfound in thehoneycomb structureof the cashew nutshell, and is a byproduct of processing cashew nuts. Since it is a strong irritant, it should not be confused with edible cashew nut oil. It is dangerous to handle in small-scale processing of the shells, but is itself a raw material with multiple uses.It is used in tropicalfolk medicineand for anti-termitetreatment of timber.Its composition varies depending on how it is processed.
These substances are skin allergens, likelacquerand the oils of poison ivy, and they present a danger during manual cashew processing.
This natural oil phenol has interesting chemical structural features that can be modified to create a wide spectrum of biobasedmonomers. These capitalize on the chemically-versatile construct, which contains threefunctional groups: Thearomatic ring, thehydroxyl group, and thedouble bondsin the flankingalkylchain. These includepolyols, which have recently seen increased demand for their biobased origin and key chemical attributes such as high reactivity, range of functionalities, reduction in blowing agents, and naturally occurring fire retardant properties in the field of rigid polyurethanes, aided by their inherent phenolic structure and larger number of reactive units per unit mass.
CNSL may be used as a resin forcarbon compositeproducts.CNSL-basednovolacis another versatile industrial monomer deriving from cardanol typically used as areticulatingagent (hardener) forepoxymatrices incompositeapplicationsproviding good thermal and mechanical properties to the final composite material.
Discarded cashew nuts are unfit for human consumption and the residues of oil extraction from cashew kernels can be fed to livestock. Animals can also eat the leaves of cashew trees.
In addition to its nut and fruit, the plant has several other uses. In Cambodia, the bark gives a yellow dye, the timber is used in boat-making, and for house-boards, and the wood makes excellent charcoal.The shells yield a black oil used as a preservative and water-proofing agent invarnishes, cement, and as alubricantor timber seal.Timber is used to manufacture furniture, boats, packing crates, andcharcoal.Its juice turns black on exposure to air, providing an indelible ink.