CASHEW NUT SHELL LIQUID: AN AGRICULTURAL BY-PRODUCT WITH GREAT POTENTIAL FOR COMMERCIAL EXPLOITATION IN KENYA

Abstract

Cashew nut shell liquid (CNSL) is the main by‐product from cashew nuts processing and is obtained during roasting of the nuts by the oil‐bath method. It may also be obtained through expression of residual shells or solvent extraction of the pulverized shells.Kenya  has  the  potential  to  produce  200,000  Tonnes  of  cashew  nuts  and  45,000 Tonnes of CNSL if all the nuts were to be processed locally and with recovery of the liquid.  Currently,  the  country  realizes  only  about  5‐10%  of  its  nuts  production potential.  Processing  of  the  nuts  has  been  left  to  small  scale  processors  who  in many  cases,  burn residue  shells  as  fuel  or  as  waste.  This  practice  pollutes  the environment  profoundly  through  emission  of  thick  dark  smoke  with  particulate matter. No CNSL is recovered in Kenya currently. The aim of this review paper is to highlight  a  number  of  products  which  can  be  manufactured  in  Kenya  based  on research initially done at Kenya Industrial Research and Development Institute and more recently at Jomo Kenyatta University of Agriculture and Technology Recovery of CNSL and its exploitation in Kenya will not only enhance the economic returns to the  cashew  industry  but  also  contribute  significantly  to  conservation  of  the environment. It is recommended that further work be done to scale‐up production of  CNSL based products and demonstrate feasibility of  the same. Production and local processing of  the cashew nuts accompanied by recovery of  CNSL should be enhanced.