Rotor Mill Makes Short Work Of Cocoa

Cocoa beans are exported worldwide for use in chocolate products and loved for their sweet taste by billions. Grown mainly in Indonesia, West Africa and South America the beans have to undergo several processes before being usable in foodstuffs.

They are roasted, peeled and cracked open and the broken pieces, called nibs, are then ground to a semi-fluid cocoa mass. This is then pressed and patty ground to make cocoa powder and butter.

The whole process involves the use of complex equipment, and a Fritsch rotor mill is the ideal solution for creating a fine, pourable powder.

Using a rotor mill to process cocoa beans

When tasked with processing amounts of 2kg of cocoa beans in a way so they could be further processed in an experimental lab into a chocolate mass, a Fritsch rotor mill solved the problem.

The Variable Speed Rotor Mill PULVERISETTE 14 is well-suited to the task of grinding the nibs to a fine, pourable powder.

It is capable of processing 100g of nibs in under a minute utilizing a 2mm sieve. A 1mm sieve was unsuccessful, but 2mm gives an adequate fineness. A potential avenue for further fineness could include mixing with dry ice. Tests have not been carried out, but this presents a promising approach for obtaining an even finer, pourable powder.

Furthermore, inspection of the open laboratory grinding chamber revealed enough room for additional nibs. To reach the required amount of 2kg, the nibs can be worked in batches or the rotor mill can be equipped with the conversion kit for the comminution of large quantities.

Sensory testing with a mortal mill

The Mortar Mill PULVERISETTE 2 is proven for sensory testing. It passes the energy with pressure and friction to the material to be milled. The applied energy per time unit is much less than with a planetary ball mill.

In this process, the sample remains in the mortar mill and the fat is only partially squeezed from the grain to form a clod-shaped mass.

For sensory tests where the mechanical strains and consistency of the sample have to be imitated, higher temperatures must be used. For this, a zirconium oxide mortar bowl and pestle is recommended and both should also be warmed. The heat energy produces the homogenous mass capable of flowing in 10 minutes.

Sample examination for contaminants

When the sample needs to be examined for pesticides, mycotoxins and heavy metals, the Planetary-Ball Mill PULVERISETTE 6 classic line should be used. This instrument gives an absolute homogenous mass in a very short time, although sensory testing is influenced by the high application of energy.

Date added: 2015-05-25 11:22:46