Debacterisation system
for cocoa beans
The first handling of cocoa, fermentation and drying, takes place in the countries of origin, mainly in Africa and South America, where health and hygiene standards are not always known or consistently followed. Confectionery companies receive the dried cocoa beans, ready to be processed into cocoa mass, chocolate, powder and cocoa butter.
The bacterial load is always very high and cannot be eliminated through traditional roasting alone by means of heat with hot air. Some bacteria, known as heat-resistant bacteria, are able to survive the roasting process in a dry environment even at relatively high temperatures. As a result, the finished products are heavily contaminated.
THE STUDY
Starting from the assumption that bacteria are mainly distributed on the surface of the shell and that their removal takes place in a hot and humid environment, TECNO 3 has focused its design on a system to be integrated into the continuous processing line between the cleaning station and the hot air roaster for whole beans.
This system must allow the beans to remain in contact with the very hot and humid air in the environment for a relatively short amount of time, but in such a way that the flora can be removed from the skin without altering the underlying cotyledon.
THE SOLUTION
The system implemented by TECNO 3 processes a dosed amount of beans with superheated steam for the time required to carry out the operation. It is therefore a discontinuous process, yet it is so fast that it could easily be integrated into continuous processing lines.
It consists of two vertically stacked conical tanks communicating through a tube equipped with two valves ensuring perfect insulation. The quantity subject to treatment goes to the upper tank meant for cocoa beans receipt. The lower tank, a process reactor, receives the right dose of product, stirs it and processes it with superheated steam.
The vapour feeding takes place when the upper loading and lower emptying valves are perfectly closed. At the end of the process, the lower valve opens and the beans descend to be sent to the next stage. The processing cycle is automatically repeated, thus feeding the continuous roaster.
THE REQUEST
The first handling of cocoa, fermentation and drying, takes place in the countries of origin, mainly in Africa and South America, where health and hygiene standards are not always known or consistently followed. Confectionery companies receive the dried cocoa beans, ready to be processed into cocoa mass, chocolate, powder and cocoa butter.
The bacterial load is always very high and cannot be eliminated through traditional roasting alone by means of heat with hot air. Some bacteria, known as heat-resistant bacteria, are able to survive the roasting process in a dry environment even at relatively high temperatures. As a result, the finished products are heavily contaminated.
The result
The smooth operation of the system is now proven by the many satisfied customers that have installed the system. Bacteriological analyses have shown and continue to show a significant reduction of the bacterial load on the samples taken after roasting during the various stages of processing, up to the finished product.
TECNO 3 guarantees results up to 1000 CFU/g on roasted beans, even if the values found are generally much lower.
An interesting technological observation is that the humidity condensed on the shell during debacterisation facilitates its complete removal from the cotyledon by means of heat during roasting, making separation easier during the winnowing stage.
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