Fundamental artificial drying characteristics of cocoa beans
AbstractA series of experiments was carried out in order to determine the fundamental drying characteristics of cocoa beans, using air under constant controlled conditions. These experiments indicated that there were three separate drying periods. In the first period the rate of drying was constant, the value of this constant rate being a function of both air temperature and velocity. There was a complex mechanism of drying in this period, but the rate of drying was controlled by the rate of heat transfer to the beans from the air stream. The testa dried out considerably in this period. In the second period, the moisture in the internal passages of the bean was transferred to the air stream through the testa. The bean temperature began to approach the air temperature in this period and the beans underwent a considerable change of shape. In the final period, the moisture remaining in the matrix of the nib was removed, the drying being extremely slow. The rate of drying was a function only of air temperature in the second and third periods.