Cashew is the common name of a tropical Evergreen Anacardium occidentale, in the family Anacardiaceae. It is native to South America and is the source of the cashew nut and the cashew apple, an accessory fruit. The tree can grow as tall as , but the dwarf cultivars, growing up to , prove more profitable, with earlier maturity and greater yields. The cashew nut is edible and is eaten on its own as a snack, used in recipes, or processed into cashew cheese or cashew 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, astringent fruit drink or fermented and distilled into liquor.
In 2023, 3.9 million of cashew nuts were harvested globally, led by the Ivory Coast and India. In addition to the nut and fruit, the shell yields derivatives used in lubricants, waterproofing, and paints.
The fruit of the cashew tree is an accessory fruit (sometimes called a pseudocarp or false fruit).
The true fruit of the cashew tree is a kidney-shaped or boxing glove-shaped drupe that 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 single Nutshell-encased seed, which is often considered a nut in the culinary sense. The seed is surrounded by a double-shell that contains an allergenic natural phenol resin, anacardic acid - which is a potent skin Irritation chemically related to the better-known and also toxin allergenic oil urushiol, which is found in the related poison ivy and lacquer tree.
The generic name Anacardium is composed of the Greek prefix ana- (), the Greek cardia (), and the Neo-Latin suffix . It possibly refers to the heart shape of the fruit, to "the top of the fruit stem" Merriam-Webster: "from the heartlike shape of the top of the fruit stem" or to the seed. 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. The epithet occidentale derives from the Western (or Occidental) world.
The plant has diverse in various languages among its wide distribution range, including anacardier (French language) with the fruit referred to as pomme de cajou, (), or (Portuguese).
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 , 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 tall and start producing after the first year, with economic yields after three years. The cashew nut yields for the traditional tree are about 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.
The nutshell of the cashew nut contains oil compounds that can cause contact dermatitis similar to poison ivy, primarily resulting from the , anacardic acid, and cardanol. 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 in nanomaterials and biotechnology.
Cashews are commonly used in Indian 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 of Goa Kaju are used whole for making curries and sweets. Cashews are also used in Thai cuisine and , 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 ( 'monkey rose apple').
In the 21st century, cashew cultivation increased in several African countries to meet the manufacturing demands for cashew milk, a plant milk alternative to dairy milk. In Mozambique, bolo polana is a cake prepared using powdered cashews and mashed potatoes as the main ingredients. This dessert is common in South Africa.
In Brazil, cashew fruit juice and fruit pulp are used to make sweets, and juice mixed with alcoholic beverages such as cachaça, 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 called dulce de marañón (marañón being 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, its 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 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.
These substances are skin allergens, like lacquer and 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 biobased . These capitalize on the chemically-versatile construct, which contains three : The aromatic ring, the hydroxyl group, and the in the flanking alkyl chain. These include polyols, 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 for carbon composite products. CNSL-based novolac is another versatile industrial monomer deriving from cardanol typically used as a cross-link agent (hardener) for epoxy matrices in composite applications providing good thermal and mechanical properties to the final composite material.
Distribution and habitat
Cultivation
Tonnes 1,044,450 782,000 347,634 164,152 136,264
Production
Trade
Toxicity
Uses
Nutrition
Nut and shell
Husk
Apple
Alcohol
Nut oil
Shell oil
Animal feed
Other uses
See also
External links
|
|