Improvement of industrial processes in Colombia. Case study: Cocoa pressing process in a chocolate factory

Abstract

This work explored an industrial-scale cocoa liquor pressing process used to obtain two standard fat-reduced cocoa powders with 12% and 16% wt. fat, respectively. A novel methodology was developed to sample and characterize fat content in cocoa cakes as released from the press before the powdering. Cocoa liquors with ~ 53% wt. fat, and with solids containing maximum ~1% wt. of particle below mesh 200 were pressed at 90 °C, and up to 550 bar following a specific time-pressure profile. Fat content in samples was measured with a pulsed nuclear magnetic resonance spectrometer. Experiments enabled to evaluate the variability of fat content of products from different batches, in different cakes from a batch, and within the cakes, verifying large average deviations (~ 5% wt.). By using a Kernel canonical correlation analysis with a Kriging interpolation approach, it was possible to map the fat content profile within the cakes, enabling to identify suitable sampling areas in the cakes for consistent and more accurate measurements of fat content in the product. Finally, the developed methodology was used to characterize different pressing batches at the industrial facility, and to correlate the required processing time for a specific fat content in the liquor.