The cashew tree (its Latin name: Anacardium occidentale) is a tropical evergreen tree that produces the cashew seed and the cashew apple. And it grows in the many gardens of Trinidad and Tobago.
A tree can grow as high as 15 m (48 ft). Another variety is the dwarf cashew (about 6 meters or 20 feet tall) but we have not seen any this small here yet. The cashew apple is a light reddish to yellow fruit, whose pulp is yellow to a deep orange color and can be processed into a sweet, astringent fruit drink mixed with other fresh fruits. Some will eat the fruit like an apple. They are very fragrant and the taste is like cashew hints, sweet and sour-ish. The cashew seed, often simply called a cashew, is widely consumed.
Even the shell of the cashew seed has a good use. It yields derivatives that can be used in many applications from lubricants to paints. The species are originally native to northeastern Brazil. Not too far away from Trinidad and Tobago!
What makes the cashew toxic?
The seed is surrounded by a double shell containing an allergenic phenolic resin, anacardic acid, a potent skin irritant chemically related to the better-known allergenic oil urushiol which is also a toxin found in the related poison ivy.
People who are allergic to cashew (or poison ivy) urushiols may cross-react to mango or pistachio which are also in the Anacardiaceae family. Some people are allergic to cashews, but cashews are a less frequent allergen than tree nuts or peanuts.
Most of us who has no allergies for nuts do agree that cashew has a nice flavor. Usually eaten just so or mixed with other nuts such as almonds, peanuts and walnuts. So how come the nuts we eat are safe?
How locals remove he resins and acid out of the cashew nut
Simply said: Burn it!
Properly roasting cashews destroys the toxin, but it must be done outdoors as the smoke (unlike that from burning poison ivy) contains urushiol droplets which can cause severe, sometimes life-threatening, reactions by irritating the lungs.
We upload some pictures showing a roast session of the cashew nuts. Outdoors and well ventilated.
Scientific source: Wikipedia