Cashew

The cashew tree is native to Brazil. The Portuguese introduced the tree to Africa and India. It belongs to the same family as the mango and the pistachio. The tree produces fleshy applelike fruits, each with a single seed—the cashew nut—growing from the bottom as a hard protuberance. The nut is protected by a double shell (or actually three shells, if you count the skin on the nut itself). The space between the inner and outer shells is filled with a toxic oily brown liquid called, appropriately enough, cashew nut shell oil. This oil is used to make resins and alkali-resistant flexible materials. Because small amounts of the oil are found on the inner shell and the kernel itself, the nuts are always heated before shelling to destroy the toxicity and avoid burns on the skin of the workers. Cashew nuts contain almost 50 percent fat and should therefore be stored, covered, in the refrigerator or freezer to prevent them from becoming rancid.