Anacardium occidentale, cashew (caju in Portuguese) is a small tree probably native to the arid and sandy northeast of South America but which is now present in the majority of warm countries (especially in coastal areas).
It is planted both to recolonize and stabilize deforested and arid areas as well as for industrial fruit production or in association with other tropical crops (cotton for example) or only as a fruit tree in tropical gardens.
The cashew tree is a medium-sized tree but covers a large area with spreading branches that can descend to the ground on unpruned trees.
Its foliage is always green, simple, alternate leaves, oblong leathery and rounded at their tips 10-15 cm by 15 to 20 cm.
Discreet flowers in terminal panicles comprising male flowers and female flowers, they are attractive to bees who make quality honey from them.
Its fruit is characteristic, it includes two parts:
- A fleshy, oblong, pear-shaped part, 5 to 10 cm long, green in color becoming yellow or orange-pink as it ripens. It is the peduncle of the very dilated fruit, a false fruit therefore, it has a fibrous texture and a tangy and slightly acrid, astringent flesh. It’s the cashew apple.
- At the lower part of this cashew apple there is the real fruit or cashew nut, shaped like a kidney or a large bean 2 to 3 cm long, green in color turning brown.
This fruit contains an edible kernel but its wall contains very caustic phenolic substances which mean that in many countries only the cashew apple is consumed.
CASHEW, AN EDIBLE PLANT with its OILSEED NUTS and APPLES RICH IN VITAMIN C AND ANTI-OXIDANTS
The kernel of the cashew nut is extracted with difficulty because of the caustic substances in its shell.
It is found commercially in cooked and salted form, more rarely in fresh form.
- It contains, when dry, approximately 50% of fatty substances (lipids), 20% of carbohydrates and 18% of proteins (proteins), interesting quantities of B group vitamins, vitamin E, mineral salts (potassium, magnesium, calcium and iron), soluble and insoluble fiber.
- Lipids are of interest in dietetics because they are mainly (80%) monounsaturated and dominated by oleic acid.
The carbohydrate percentage is high for an almond and allows fresh cashew to be used in many cooked dishes.
- In the West it is most often eaten cooked and salted, as an aperitif; the large quantity of salt removes its dietary benefit.
- The natural and ripe cashew apple contains a lot of vitamin C (in % 4 to 5 times more than an orange) but it is quite astringent.
It is a good source of magnesium and potassium.
You can fragment it, remove the ends of the cashew apple which contain the most tannin and « disgorge » it with a little salt to incorporate it into a salad.
We can also extract the acidic but fragrant juice by pressing and remove a large part of the tannins which cloud the juice by precipitating them with starchy solutions or powdered gelatin.
- Example:
For 1 liter of cashew juice in a glass or stainless steel container, add 75 to 150 ml of cold rice water, mix well and allow to sediment. Collect the supernatant which has cleared and consume it immediately or keep it cold in a glass container. - In Brazil you can find “cajuina” in stores, which is cashew apple juice; Sterilization by heat gives it a golden color (but reduces its vitamin C content).
- Cashew apple juice ferments easily, « cashew wine » or a consumable alcohol is obtained by distilating the fermented juice.
An oily, highly caustic liquid is extracted from the cashew nut shell, and has numerous applications in industrial synthesis chemistry (Cashew Nut Shell Liquid or CNSL) in the paint, ink and plastics industries..
ANACARDIUM OCCIDENTALE MEDICINAL PLANT
We have detailed above the dietary benefit of the cashew apple which provides the body with a significant quantity of vitamin C, a vitamin necessary for the proper functioning of the body and which strengthens our ability to resist viral or bacterial infections.
The other interest of cashew is the medicinal tannin content of its bark or leaves.
A bark decoction gives a concentrated tannin solution that can be used to clean a wound, even an infected one, to treat a burn or an oozing dermatosis, as a sitz bath or vaginal injection, or diluted for digestive disorders (diarrhea).
- Example: a fragment of cleaned bark measuring 5 by 10 cm, fragmented in 1/2 to 1 liter of boiling water, decoction for 15 to 20 minutes.
The leaves are less concentrated in tannin, they can be used to treat: diarrhea or an episode of colitis, as a mouthwash or gargle (canker sores, mouth sores, sore throat), to clean a wound or burn.
You can also use this infusion decoction of leaves to alleviate disorders secondary to type 2 diabetes.
- Example: a handful of leaves in 1 liter of boiling water infusion for 10 minutes (for a slightly concentrated solution), or decoction for 10 minutes.
The slightly concentrated solution is the one preferred to alleviate type 2 diabetes at a rate of 1/4 to 1/2 liter of infusion twice during the day.
The oily resin contained in cashew nut husks is sometimes used (but with care) to destroy warts or to help heal (cauterize) « cracks » or fissures on the soles of feet and toes, common in the tropics.
It is obtained by heating the whole nut with tongs or in a container; the caustic resin oozes out under the action of the heat, but can catch fire if the heat is too strong and it is brought close to a flame.
The smoke released is then very irritating and toxic.
CASHEW OR CASHEW CULTURE
Anacardium occidentale is a tree or shrub very resistant to drought, not demanding on the qualities of the soil but which does not tolerate flooded, overly humid soils or cold climates.
It grows very well in sandy soils because its root system is deep and well developed.
Propagation is most often done from seeds which germinate without too much problem and which are best planted to avoid damaging the taproot of the young plant when transplanting it.
In India where cashew is very widespread, agronomists also use layering and grafting of improved varieties.
Plantings can be fairly tightly spaced, then thinned out to give a tree every 10 m or so.
We can only encourage the planting of this tree in hot areas, especially when the soil has been weakened by uncontrolled deforestation and in association with annual crops such as cotton in fragile areas with low rainfall.
Copyright 2024 : Dr Jean-Michel Hurtel
You are on www.phytomania.com
French site dedicated to medicinal plants and essential oils