Cashew Nut Utility

Cashew is a very popular nut that belongs to the Anacardiaceae family. Cashew’s English name comes from a Portuguese word. It grows well in tropical climates for cashew and cashew apples. Name Anacardium refers to the shape of the fruit that resembles an inverted heart. The cashew tree is small, evergreen and reaches a height of 10-12 meters with an irregular trunk. The leaves are somewhat spiral in shape, leathery in texture, elliptic to ovate, and about 4-22 cm long and 2-15 cm broad with a smooth margin. The flowers are born in a panicle or corymb 26 cm long. The flowers are green but later turn red with five thin, pointed petals and are 7–15 mm long. The cashew fruit is an accessory fruit that has a pear-shaped structure that develops from the pedicel and flower receptacle. The fruit is known as cashew and cashew in Central America. The fruit is pale and turns red after ripening and is 5-11 cm long. The fruit is edible with a sweet smell and a sweet taste. The pulp of the cashew apple is juicy but the skin is fragile, making it difficult to transport.

The true fruit of the cashew is a kidney-shaped drupe that develops at the end of the cashew apple. The drupes develop first and then the pedicel expands into cashew. Inside the fruit is a single fruit known as a cashew. In the botanical sense, the cashew is actually the seed. The seed is surrounded by a hard shell that contains allergenic phenolic resin, anardic acid and a potent skin irritant. The chemical nature of the skin irritant is exactly similar to that of the allergenic oil known as urushiol. Some people are allergic to cashews, but the nuts are less allergic compared to other tree nuts and peanuts. The cashew is actually native to Brazil, but the credit for introducing this nut to India goes to the Portuguese. From India, the fruit spread to Southeast Asia and Africa. Cashew Shell Liquid (CNSL) is a product produced after processing cashew nut rich in anacardic acids. The liquid is very effective in treating dental abscesses caused by Gram-positive bacteria. The bark is scraped, soaked, boiled, and used to treat diarrhea. The gum obtained from the tree is used for varnishing. The seeds are ground to make powders that are used as an antivenom against snakebites. Walnut oil has antifungal properties. Anacardic acid is used for the production of cardanol, which is used as a friction and lining material.

The cashew nut is used as a popular snack that is salted or sweetened. The walnuts are also covered in chocolate and are somewhat cheaper than peanuts and almonds. The walnut is also an important agent in Thai, Chinese and Indian cuisines. In Indian cuisine they are used to garnish sweets and other preparations. In India, particularly in Goa, the cashew apple is crushed and the juice obtained is left to ferment for 2-3 days. The fermented juice then undergoes a double distillation which results in the production of a drink called feni. Nuts are a good source of energy, carbohydrates, sugars, fats, proteins, dietary fibers, vitamin B complex, vitamin C, calcium, magnesium, phosphorus, zinc, and iron. The fats and oils present in cashew oil contain 54% monounsaturated fat, 18% polyunsaturated fat and 16% saturated fat, and 7% stearic acid.