Screening of new cocoa types for insect infestation and biochemical analysis of the stored beans

Abstract

New cocoa types, mainly hybrids, are being developed and selected by the Cocoa Research Institute of Ghana (CRIG) on the basis of their early establishment and high yields. It is, however, necessary to screen them for their attractiveness to insect pests and diseases to ensure that the materials given to farmers are not prone to insect pests and diseases, both in the field and during storage of the beans. This study reports on investigation on the susceptibility/tolerance in five hybrid cocoa types to four storage insect pests (both beetles and moths). It also reports on the effects of insect pests' infestation on the levels of free fatty acids (FFA), the percentage shell, sugar and fat contents. For all the five cocoa types tested, the level of insect infestation was minimal (0-1) by four months after their introduction into the beans. The results also showed that, Lasioderma serricorne (Fabricus), Tribolium castaneum (Herbst), Ephestia cautella (Walker) and Corcyra cephalonica (Stainton) had no adverse effects on the beans within the four-month experimental period. The fat content remained high whilst the FFA levels remained within acceptable limits. There was virtually no reduction in the sugar and shell contents of the cocoa beans. © 2006 Asian Network for Scientific Information.