A comparative study of some physical properties of large and medium size cocoa beans from Ghana

Abstract

The physical properties of Cocoa are necessary for the design of equipment to handle, transport, process and store the commodity. Cocoa beans can be categorised into several groups based on their sizes. A comparative study of the physical properties of the large group (category B) and the medium group (category D) Cocoa beans were evaluated as a function of moisture content within the moisture content range of 5.67 - 25.04% wet basis. The bulk density decreased linearly from 559.60 - 505.05 kg/m3 between a moisture content range of 8.6 - 23.78% for category B and from 699.9 - 630.18 kg/m3 between a moisture content of 9.19 - 25.05% for category D. The 1000-bean mass increased linearly from 984.75 – 1112 g and 1125 – 1247 g when moisture increased from 9.19 - 25.04% and 8.6 - 23.78% for categories D and B respectively. The emptying angle of repose for cat D at m.c. range of 9.19 - 25.04% increased from 27.98 – 46.52. Cat B. with m.c. range of 7.56 – 18.8% also increased from 27.26 – 37.470. The filling angle of repose for category D increased with values ranging from 30.33 - 42.980 between m.c. of 9.19 - 25.04%, whiles for category B at mc of 5.67- 22.0% the filling angle of repose increased non-linearly from 23.74 – 33.810. The static coefficient of friction increased linearly from 0.56 - 0.69, 0.48 - 0.60 and 0.21 - 0.28 for plywood, mild steel and rubber respectively for category B and for category D, a linear increment in static co-efficient of friction from 0.53 - 0.62 and 0.56 - 0.63 was observed for mild steel and plywood while in the case of the rubber, static co-efficient of friction increased non linearly from 0.12 - 0.32