A review on the technological evolution and advancements of cocoa dryers

Cocoa (Theobroma cacao) is an important commodity crop that is cultivated to produce cocoa beans which serve as a major ingredient in chocolate processing. Fresh cocoa beans need to undergo fermentation and drying in order to develop the flavor precursors. Cocoa drying is usually carried out by conventional sun and artificial drying techniques. However, these techniques are not efficient and the designs are still crude in many cases. Several published works have attempted to improve the drying efficiency by mechanizing the drying process and developing advanced dryers (heat pump, adsorption, infrared, fluidized bed and solar dryers). These studies showed that both drying efficiency and product quality could be improved substantially. The aim of this review is to provide a technological advancement of the cocoa drying techniques used by the smallholders and plantations and compare the effectiveness of these dryers including discussion on the development of non-conventional dryers with advanced features.