(119c) Standardization of Cocoa Butter Extraction in the Cocoa Pressing Process in a Chocolate Factory

At chocolate factories, dry cocoa beans are roasted, milled, sieved to remove seed shells, and crushed to produce a viscous mass (cocoa paste) which by heating melts into the cocoa liquor. This liquor contains roughly equal proportions of fat (cocoa butter) and solids. In order to reduce the fat content in cocoa liquor a hydraulic pressing process is commonly used. By compressing cocoa liquor under high pressure against a filter media, cocoa butter is extracted, and the remaining solid cake is pulverized to obtain cocoa powder. Fat content is a major specification in cocoa powder, being 12% and 16% w/w commercial standards in the chocolate market. In order to control this specification, a trial an error method is generally applied at industrial scale. Depending on the required fat content and the liquor characteristics, extraction time in the press is adjusted. This operation is not desirable because it reduces productivity and affects quality of the product. In order to standardize operating conditions during pressing process, in this work it was studied the effect of cocoa liquor fat content and pressing time in the final fat content of powdered cocoa. By mean of a statistical approach based upon preliminary experiments, and using the statistical software R, it was established a reliable method for cake sampling at the industrial scale press. Using this technique, and by taking the appropriate average over different solid cakes from the press, a standardized method for the measurement of fat content in powdered cocoa was established. By using this characterization technique, a series of extractions experiments were carried out (using a box-behnken design) varying liquor fat content and pressing time, and observing the effect over solid cake fat content. Results were correlated with a linear expression and a good agreement between model and experiments was observed. By implementing obtained model during extraction process in the chocolate factory increased cocoa powder and cocoa butter daily production, and significantly reduced the amount of non-conforming product.