The cashew, cachou or bombay nut is the seed of the cashew tree, also known as anacardium occidentale. The tree is native to Brazil, but harvest and production have expanded to Asia and, more recently, Africa.
The aforementioned anacardium occidentale is native to Brazil and was first introduced to India some 500 years ago. Portuguese explorers planted the tree in Goa to prevent coastal erosion, as they tend to have extensive root systems, keeping the soil in place. Its presence soon spread, expanding its conquest of the entire coastal region of the peninsula thanks to elephants eating the trees’ fruit and dispersing its seeds. It was the beginning of the global industry it is today;
The largest cashew nut producing countries are India, Vietnam, Indonesia, Mozambique, Madagascar, Brazil, Ivory Coast, Burkina Faso, Benin, Ghana and Togo. Most of the cashew nuts grown in Africa are shipped to India and Vietnam, where they are then processed into the final edible nut in just a few steps. Due to developments in African countries, more and more raw nuts are processed in the country of harvest. The economy of the West African republic Guinea-Bissau is 95 percent dependent on the export of cashew nuts. Current global production of raw cashew nuts exceeds 2 million tons, or about a quarter of the world edible nuts production.
The fruit, or ‘cashew apple’, which resembles a bell pepper, of the anacardium occidentale is what is called a ‘false fruit’. The real fruit, a single seed carrying the cashew nut, hangs from the apple. The fruit matures in 90 to 100 days after flowering. The ripe fruits normally start to drop in late January. The peak fruit collection period is between February and March, with a few late maturing trees dropping their fruits in April. Cashew harvesting can take place about two months after the fruit has set, when the apple takes on a pink or red cast and the nut turns gray. Alternatively, you can wait until the fruit falls to the ground, when you know it’s ripe. After harvesting, twist the nuts off of the apples by hand.
The actual fruit containing the seed is inconspicuous and hangs under the mock fruit. The skin contains poison, known as CNSL or ‘cashew nut shell liquid’, a highly corrosive oil which can cause severe skin irritation. Production of the raw nut kernels is therefore very difficult, and different in many production regions. After removing the in-shell nuts from the cashew apple, processing typically includes the following steps: preparing the nuts for shelling (drying, sizing, cleaning, steam cooking or roasting), shelling (with automatic, semi-automatic or manual machines), peeling (drying shelled nuts, automatic or manual peeling), grading (color sorting, sizing, cleaning) and packing (weighing, vacuum sealing).
The cashew apple is used for its juicy but acidic pulp, which can be eaten raw or used in the production of jam, chutney, or various beverages. However, the cashew apple contains much tannin and is very perishable. In many production regions, the fruit is discarded after removal of the cashew nut. The nuts removed from the skin are processed in various ways: they can be fried in oil (and possibly salted), roasted with hot air, coated in sugar like a sugar peanut, coated with a batter similar to bubbly nuts or used as a kitchen ingredient. Raw cashews found in health food shops have been cooked but not roasted or browned. Cashew nuts are a common ingredient in Asian cooking. They can also be ground into a spread called cashew butter similar to peanut butter. Cashews have a very high oil content, and they are used in some other nut butters to add extra oil. Due to its taste, the cashew is seen as an upper-class nut, becoming more and more interesting for industrial processing and its use in cookies and cereals or as a topping on ice-cream. The CNSL in the shells of the nut is useful too; it can be fractionated in a process similar to the distillation of petroleum, and has two primary end products: solids that are pulverized and used as friction particle for brake linings, and an amber-colored liquid that is aminated to create phenalkamine curing agents and resin modifiers.
As a general rule, the value of cashew nuts increases from production to consumer depending on the market. The price of unprocessed cashew nuts for instance is lower than that of processed cashews. In Vietnam, cashew exports are mainly live unprocessed kernels.
The origin of cashew nuts significantly affects their quality and nutritional composition. All cashew nuts are classified according to different standards, applicable to exports and domestic consumption. Another factor are the complexities of the production process and the fact that not all regions have fully switched to mechanization, which would require huge investments as well as state support. Price factors include grain size, nutritional content, origin, processing stage, in addition to exchange rates and transport costs.
Cashews at the beginning of the season usually have higher prices, thanks in part to a more evenly colored appearance and a higher quality of nutrition.