The Impact of Insect Infestation on Stored Purpled Cocoa Beans

Abstract

Under-fermentation of cocoa beans produces purple beans. The fermentation period is 6 to 7 days but some cocoa farmers under-ferment their cocoa beans leading to the development of purple cocoa beans. This study determined the impact of insect infestation on stored purple cocoa beans. Wet cocoa beans were fermented for 1, 2, 3, 4 and 5 days to produce the purple beans. Ephestia cautella and Tribolium castaneum, both singly and in combination, were introduced into the cocoa beans and stored for different (30, 60, 90 and 120 days) period. Insect population, percentage weight loss and the contaminants produced by these insects were determined. Cocoa beans infested with E. cautella alone had the highest population of 297.0 ± 22.7. Beans fermented for 3 days had the lowest insect population both singly and in combination after 120 days of storage. The highest percentage weight loss was recorded in cocoa beans fermented for one day (10.1 ± 1.87%) and 4 days (10.1 ± 8.74%). T. castaneum did not cause much damage to the cocoa beans but E. cautella alone caused significant damage to stored cocoa beans. Insect infestation and poor fermentation contribute significantly to the reduction in quality of cocoa beans.