Cashews

The cashew fruit is unusual in comparison with other tree nuts since the nut is outside the fruit. The cashew apple is an edible false fruit, attached to the externally born nut by a stem. In its raw state, the shell of the nut is leathery, not brittle. It contains the thick vesicant oil, CNSL, within a sponge-like interior. A thin testa skin surrounds the kernel and keeps it separated from the inside of the shell. The primary products of cashew nuts are the kernels which have value as confectionery nuts. Cashew nut shell liquid (CNSL) is an important industrial raw material for resin manufacture and the shells can be burned to provide heat for the decorticating operation

Processing overview

‘Cashews are expensive because there is just one nut per fruit. Cashews trees have to be farmed, harvested, separated from the false fruit, roasted, cooled, cracked open, peeled, sundried, and sorted – and only then can you sell them as raw nuts. The amount of value added is incommensurate to the amount of labour that goes into it.

The most difficult step in how cashew nuts are processed is extracting the kidney-bean-shaped nut from its shell, which is labour-intensive and requires a skilled workforce. When cracked open, the shell oozes a highly corrosive oil referred to as CNSL or ‘cashew nut shell liquid’. This oil, when in contact with skin, causes burns and sores which often present health risks for workers [Reference www.foodunfolded.com]

The process depends on whether it is done using a traditional method that is manually done or the semi-auto process adopted by most high-volume suppliers.