Cashew

Anacardium occidentale, from Köhler's Medicinal Plants (1887)

Its English name derives from the Portuguese name for the fruit of the cashew tree: caju (Portuguese pronunciation: [kaˈʒu]), also known as acaju, which itself is from the Tupian word acajú, literally meaning "nut that produces itself".[1]

The generic name Anacardium is composed of the Greek prefix ana- (ἀνά-, aná, 'up, upward'), the Greek cardia (καρδία, kardía, 'heart'), and the New Latin suffix -ium. It possibly refers to the heart shape of the fruit,[6] to "the top of the fruit stem"[7] or to the seed.[8] The word anacardium was earlier used to refer to Semecarpus anacardium (the marking nut tree) before Carl Linnaeus transferred it to the cashew; both plants are in the same family.[9] The epithet occidentale derives from the Western (or Occidental) world.[10]

Flower of cashew tree

Cashew tree

The cashew tree is large and evergreen, growing to 14 m (46 ft) tall, with a short, often irregularly shaped trunk. The leaves are spirally arranged, leathery textured, elliptic to obovate, 4–22 cm (1.6–8.7 in) long and 2–15 cm (0.79–5.91 in) broad, with smooth margins. The flowers are produced in a panicle or corymb up to 26 cm (10 in) long; each flower is small, pale green at first, then turning reddish, with five slender, acute petals 7–15 mm (0.28–0.59 in) long. The largest cashew tree in the world covers an area around 7,500 m² (81,000 sq ft) and is located in Natal, Brazil.

The fruit of the cashew tree is an accessory fruit (sometimes called a pseudocarp or false fruit).[1] What appears to be the fruit is an oval or pear-shaped structure, a hypocarpium, that develops from the pedicel and the receptacle of the cashew flower.[11] Called the cashew apple, better known in Central America as marañón, it ripens into a yellow or red structure about 5–11 cm (2.0–4.3 in) long. It is edible and has a strong "sweet" smell and taste.

The true fruit of the cashew tree is a kidney– or boxing-glove–shaped drupe that grows at the end of the cashew apple. The drupe develops first on the tree, and then the pedicel expands to become the cashew apple.[1] The true fruit contains a single seed, which is often considered a nut in the culinary sense. The seed is surrounded by a double shell that contains an allergenic phenolic resin, anacardic acid—which is a potent skin irritant chemically related to the better-known and also toxic allergenic oil urushiol, which is found in the related poison ivy and lacquer tree. Some people are allergic to cashews, but they are a less frequent allergen than tree nuts or peanuts.[12]

The cashew tree is native to northeastern Brazil, but the Portuguese took it to Goa, India between 1560 and 1565. From there, it spread throughout Southeast Asia, and eventually Africa.

A woman uses a machine to shell cashews in Phuket, Thailand.

Cashews as a snack

Culinary uses for cashew seeds in snacking and cooking are similar to those for all tree seeds called nuts.

Cashews are commonly used in South Asian cuisine, whole for garnishing sweets or curries, or ground into a paste that 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. In Goan cuisine, both roasted and raw kernels are used whole for making curries and sweets. Cashews are also used in Thai and Chinese cuisines, generally in whole form. In the Philippines, cashew is a known product of Antipolo, and is eaten with suman. The province of Pampanga also has a sweet dessert called turrones de casuy, which is cashew marzipan wrapped in white wafers. In Indonesia, roasted and salted cashews are called kacang mete or kacang mede, while the cashew apple is called jambu monyet (lit. ‘monkey rose apple’).

In the 21st century, cashew cultivation increased in several African countries to meet the demands for manufacturing cashew milk, a plant milk alternative to dairy milk.[13] In Mozambique, bolo polana is a cake prepared using powdered cashews and mashed potatoes as the main ingredients. This dessert is popular in South Africa.[14]

In Brazil, cashew fruit juice and the fruit pulp are used in the production of sweets, juice, alcoholic beverages, such as cachaça, and as a flour, milk or cheese.[15] In Panama, the cashew fruit is cooked with water and sugar for a prolonged time to make a sweet, brown, paste-like dessert called dulce de marañón (marañón being a Spanish name for cashew).

The shell of the cashew nut contains oil compounds that can cause contact dermatitis similar to poison ivy, primarily resulting from the phenolic lipids, anacardic acid, and cardanol.[16] Due to the possible dermatitis, cashews are typically not sold in the shell to consumers.[17] Readily and inexpensively extracted from the waste shells, cardanol is under research for its potential applications in nanomaterials and biotechnology.[18]

In 2019, global production of cashew nuts (as the kernel) was 3,960,680 tonnes, led by Côte d'Ivoire and India with a combined 39% of the world total (table). Burundi, Vietnam, Tanzania, the Philippines, Tanzania, and Benin also had significant production of raw cashew nut. Vietnam is notable as the largest processor of cashew globally.[19]

Cashew production (with shell), 2019
Country	Production (tonnes)
Côte d'Ivoire	792,678
India	743,000
Burundi	283,328
Vietnam	283,328
World	3,960,680
Source: FAOSTAT of the United Nations[20]

Young cashew fruits

In 2014, rapid growth of cashew cultivation in Ivory Coast made this country the top African exporter.[21] Fluctuations in world market prices, poor working conditions, and low pay for local harvesting have caused discontent in the cashew nut industry.[22][23][24]

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.[25] The traditional cashew tree is tall (up to 14 m) and takes three years from planting before it starts production, and eight years before economic harvests can begin. More recent breeds, such as the dwarf cashew trees, are up to 6 m 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 metric tons per hectare, in contrast to over a ton per hectare for the dwarf variety. Grafting and other modern tree management technologies are used to further improve and sustain cashew nut yields in commercial orchards.

Raw cashews are 5% water, 30% carbohydrates, 44% fat, and 18% protein (table). In a 100 gram reference amount, raw cashews provide 553 Calories, 67% of the Daily Value (DV) in total fats, 36% DV of protein, 13% DV of dietary fiber and 11% DV of carbohydrates.[26] Cashews are rich sources (20% or more of the DV) of dietary minerals, including particularly copper, manganese, phosphorus, and magnesium (79-110% DV), and of thiamin, vitamin B₆ and vitamin K (32-37% DV) (table).[26] Iron, potassium, zinc, and selenium are present in significant content (14-61% DV) (table).[26] Cashews (100 grams, raw) contain 113 milligrams (1.74 gr) of beta-sitosterol.[26]

Cashew oil is a dark yellow oil for cooking or salad dressing pressed from cashew nuts (typically broken chunks created during processing). This may be produced from a single cold pressing.[31]

The cashew apple, also called cashew fruit, is the fleshy part of the cashew fruit attached to the cashew nut.[1] The top end of the cashew apple is attached to the stem that comes off the tree. The bottom end of the cashew apple attaches to the cashew nut, which is encased in a shell. In botanical terms, the cashew apple is an accessory fruit that grows on the cashew seed (which is the nut).

The cashew apple can be eaten fresh, cooked in curries, or fermented into vinegar, as well as 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.[1]

Cashew nuts are more widely traded than cashew fruits, because the fruit, unlike the nut, is easily bruised and has a very limited shelf life.[36] Cashew apple juice, however, may be used for manufacturing blended juices.[36]

When consumed, the apple's astringency is sometimes removed by steaming the fruit for five minutes before washing it in cold water. Steeping the fruit in boiling salt water for five minutes also reduces the astringency.[37]

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.[38]

Discarded cashew nuts unfit for human consumption, alongside the residues of oil extraction from cashew kernels, can be used to feed livestock. Animals can also eat the leaves of cashew trees.[39]

As well as the 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.[38]

As well as the botanical name Anacardium occidentale, the tree is known by common, or vernacular names. These include anacardier (French with the fruit referred to as pomme de Cajour;[38] sva:y chan'ti Khmer;[38] caju (Portuguese pronunciation: [kaˈʒu]), also known as acaju (Portuguese);[1] acajú (Tupian word ="nut that produces itself")[1]

• 
  Ripe cashew fruit
• 
  Cashew sprouts are eaten raw or cooked
• 
  Distilling cashew apple liquor (muchekele) in Mozambique
• 
  Shriveled, fermented cashew apples ready for distillation, Mozambique
• 
  Mameluca woman under a fruiting cashew tree (1641–1644) by Albert Eckhout. National Museum of Denmark
• 
  View of a cashew tree stem in Lawachara National Park, Bangladesh. Photo from 2016

• Cajuína
• Cashew pie
• List of culinary nuts
• Semecarpus anacardium (the Oriental Anacardium) is a native of India and is closely related to the cashew.