Buhler develops flavour-saving cocoa processing
has been developed for US chocolate and cocoa producer Blommer. The
process is claimed to preserve the properties of cocoa better.
A large number of process operations are required in the manufacture of fine chocolate. During the roasting of cocoa beans for example, the raw material must be treated with extreme care to ensure the full development of flavour.
To achieve this, German equipment provider Buhler has developed a process that allows for not only gentle and continuous roasting, but also the debacterisation of beans while still in their shells. This method, claims Buhler, allows the full aroma contained in the cocoa beans to be preserved.
The company claims that the debacterisation unit is capable of inactivating even heat resistant vegetative germs and spores.
The debacterisation unit was installed ahead of the roaster. It is fully automated to ensure that all cocoa beans are reliablydebacterised. At short 100-second intervals, the debacterisation system discharges a batch directly into the roaster, ensuring that the material, which has been moistened by steam, will be dried and stabilised immediately.
The Buhler system operates under pressure to increase the condensation temperature and substantially reduce the reaction time. This, says Buhler, is very important to ensure that the temperature and the moisture will not have time to migrate from the shell to the kernel.
Next comes roasting. The cocoa beans pass gently through the roaster from top to bottom in a narrow vertical duct choke-filled with material. Buhler claims that the product is not subjected to any mechanical action by, say, a drum or other agitating components. This prevents fat from the kernels migrating to the shell and thereby being lost.
An automatic dust extraction system keeps the roasting and cooling zones clean and reduces the maintenance requirement. The rugged design and construction of the system also allows long life cycles to be achieved.
In addition, roasting of the whole beans in their shells alsoprevents fat from being lost to the roasting air along with the extracted moisture. As a result, the valuable cocoa fat is entirely preserved in the cocoa.
In designing the process, system engineering was done on a virtual basis using 3D-CAD. This allowed the system to be incorporated into the existing building and in the existing upstream and downstream processes at Blommer's Chicago plant.
This is the latest confectionery processing innovation from Buhler. The firm has also been a pioneer of tailored microstructure as a means of improving the texture of the chocolate.
"A major challenge for the chocolate industry is the fact that cocoa butter has to be crystallised in stable form," Marcos Bobzin, Buhler's product manager for chocolate technology recently told FoodProductionDaily.com. "Because if the crystals within the chocolate have different melting points, then some parts of the chocolate will melt before other parts. It will become sticky, and this is the challenge from the technology point of view."
Buhler's SeedMaster is one means of achieving better texture. This piece of equipment is designed to replace conventional processes of precrystallising the chocolate mass to produce chocolate with denser texture and higher strength.
"The SeedMaster is a means of precrystallising cocoa butter and so-called CBEs (cocoa butter equivalents)," said Bobzin. "These are polyforms - in other words the different forms of fats crystallise in a complex way. Conventional processing tends to create what are known as beta-5 crystals. But with SeedMaster, we are able to make even smaller more compact crystals called beta-6."
This is significant for a number of reasons. For a start, it can enhance the lifetime of a product. "In chocolate, the fat tends to go out to the surface overtime, and this makes the product go rancid," said Bobzin. "But if the crystals are more compact, this acts as a filter. In addition, the chocolate tastes smoother."
